{"id":25,"slug":"25-mots-c-n-terminal-myristoylation-c14-fatty-acid-attached-via-amide-","title":"MOTS-c N-terminal myristoylation for enhanced membrane association and cellular uptake","status":"PROMISING","fold_verdict":"PROMISING","discard_reason":null,"peptide":{"name":"MOTS-c","class":"LONGEVITY","sequence":"MRWQEMGYIFYPRKLR","modified_sequence":"Myr-MRWQEMGYIFYPRKLR","modification_description":"N-terminal myristoylation (C14 fatty acid attached via amide bond to the alpha-amino group of Met-1)"},"target":{"protein":"5'-AMP-activated protein kinase catalytic subunit alpha-2","uniprot_id":"P54646","chembl_id":"CHEMBL2492","gene_symbol":"PRKAA2"},"rationale":{"hypothesis":"We hypothesize that N-terminal myristoylation of MOTS-c (C14 saturated fatty acid attached to the Met-1 alpha-amine) will dramatically improve its cellular and mitochondrial membrane association, enabling more efficient passive uptake into target tissues (skeletal muscle, liver) where AMPK activation drives metabolic benefit. Native MOTS-c is a small, polar, partially cationic peptide with poor predicted membrane permeability — myristoylation is a well-validated strategy for tethering peptides to lipid bilayers and has precedent in mitochondrially-targeted therapeutics. We predict the lipidated peptide retains the bioactive backbone of residues 1-16 while gaining a hydrophobic anchor that does not perturb the C-terminal cationic patch (R12-K13-L14-R16) implicated in AMPK engagement.","rationale":"Myristoylation is a canonical post-translational modification used by mitochondrial and membrane-associated proteins to achieve bilayer tethering, and synthetic N-myristoylated peptides (e.g., myristoylated AKAP, PKI peptides) show 10-100× improved cellular uptake versus unmodified controls. Attaching the C14 chain to the N-terminal alpha-amine via a stable amide bond preserves the entire 16-residue pharmacophore — including the recently validated K13R-adjacent cationic patch and the Nle1-tolerant N-cap — while addressing MOTS-c's known pharmacokinetic limitation of requiring high subcutaneous doses (5-10 mg) for systemic effect. This diverges from the last three folds (two Single residue substitutions and one Cyclization; foci of AFFINITY, STABILITY, CONFORMATION) by introducing both a new modification category (Lipidation) and a new research focus (DELIVERY) untouched in the lab-wide recent history.","predicted_outcome":"Structure prediction should show the 16-residue MOTS-c backbone retained with high pLDDT in the central region (residues 6-14), with the myristoyl chain projecting away from the peptide as a flexible hydrophobic tail (likely lower local pLDDT on the lipid itself, which is expected). The cationic C-terminal patch (R12, K13, R16) should remain solvent-exposed and unperturbed, and the overall fold should resemble the native and Nle1 variants, confirming that lipidation does not disrupt the bioactive conformation.","mechanism_class":null,"biohacker_use":null},"confidence":{"plddt":0.6253274083137512,"ptm":0.5350925922393799,"iptm":0.21112336218357086,"chai_agreement":null,"chai1_gated_decision":"RAN_BORDERLINE","binding_probability":null,"binding_pic50":null,"predicted_binding_change":null},"profile":{"aggregation_propensity":0.083,"stability_score":0.338,"bbb_penetration_score":0.168,"half_life_estimate":"moderate (~30 minutes – 2 hours)"},"narrative":{"tldr":"Fold #25 attaches a C14 myristoyl chain to the N-terminus of MOTS-c, targeting improved membrane association and cellular uptake as a delivery-focused modification — the first lipidation attempt in this lab's MOTS-c series. Structural prediction recovered the 16-residue backbone at moderate confidence (pLDDT 0.63), consistent with prior MOTS-c folds, but the peptide-target interface score was weak (ipTM 0.21), and no affinity data were produced. The modification is biologically plausible as a membrane-anchoring strategy, but creates a fundamental mechanistic tension: MOTS-c's known nuclear translocation function may be incompatible with permanent lipid-bilayer tethering. The verdict is PROMISING but mechanistically ambiguous — the delivery hypothesis is worth pursuing, but the nuclear trapping risk is a critical unresolved concern.","detailed_analysis":"MOTS-c is a 16-residue mitochondrial-derived peptide (MDP) encoded within the 12S rRNA locus of the mitochondrial genome. Its primary established mechanism involves inhibition of the folate-methionine cycle in skeletal muscle, driving AICAR accumulation and downstream AMPK activation — specifically through AMPKα2 (PRKAA2, UniProt P54646), the dominant catalytic isoform in metabolic tissues. In vivo, exogenous MOTS-c administration has demonstrated robust prevention of age-dependent and diet-induced insulin resistance in rodent models, and the peptide circulates endogenously as a hormone-like factor whose plasma levels decline with age. Pleiotropic activities in bone remodeling, gestational diabetes, and cancer suppression have also been reported, though the mechanistic basis for each remains incompletely characterized.\n\nThe MOTS-c lab series at Alembic has so far explored modifications focused on the N-cap (Fold #5, Met-1 → Norleucine, PROMISING, pLDDT 0.62) and the C-terminal cationic patch (Fold #19, K13R substitution, PROMISING, pLDDT 0.63). Both folds targeted stability or affinity improvements while preserving the backbone fold, and both returned moderate structural confidence in a consistent range. Fold #25 represents a deliberate pivot: it is the first lipidation attempt on MOTS-c, and the first fold in the lab's MOTS-c series with a DELIVERY research focus rather than AFFINITY or STABILITY. The C14 myristoyl chain is attached via a stable amide bond to the alpha-amino group of Met-1 — the same residue explored in Fold #5 — making these two folds directly complementary explorations of the N-terminal modification space.\n\nThe structural prediction for Myr-MOTS-c returned a pLDDT of 0.63 and a pTM of 0.54, consistent with the moderate-confidence range seen across the MOTS-c series. The peptide backbone is predicted to be recoverable at moderate local confidence, which supports the hypothesis that the myristoyl chain does not grossly perturb the 16-residue pharmacophore. However, the ipTM of 0.21 is notably weak — indicating that the model has low confidence in the peptide-target interface geometry relative to AMPKα2. This is consistent with the general difficulty of predicting how a lipidated peptide engages a soluble protein partner in a soluble-state structure predictor, and does not definitively indicate loss of binding. The absence of Boltz-2 affinity data and Chai-1 agreement scores means no quantitative comparison to native MOTS-c binding can be made from this single fold. Heuristic estimates suggest low aggregation propensity (0.083) and a moderate half-life (30 min–2 hours), with low BBB penetration predicted (0.168) — consistent with a lipidated, membrane-associating species unlikely to cross the blood-brain barrier efficiently.\n\nThe biological rationale for myristoylation is grounded in well-established precedent: N-myristoylated peptides such as myristoylated AKAP inhibitors and PKI fragments show 10–100× improvements in cellular uptake versus unmodified controls in cell culture and some in vivo models. For MOTS-c specifically, multiple reviews have explicitly identified poor delivery as the primary barrier to clinical translation — the native peptide requires high subcutaneous doses (5–10 mg) for systemic metabolic effect in rodents, suggesting suboptimal membrane permeation. Attaching a C14 hydrophobic anchor to the N-terminus could drive passive partitioning into plasma membranes of target tissues (skeletal muscle, liver), potentially reducing the effective dose required for intracellular AMPK engagement.\n\nHowever, the most significant scientific concern raised by this fold is the mechanistic conflict between membrane anchoring and nuclear translocation. Benayoun & Lee (PMID:31378979) established that MOTS-c translocates from the cytoplasm to the nucleus under metabolic stress conditions (glucose restriction, oxidative stress) to directly regulate adaptive nuclear gene expression. This nuclear translocation is not a secondary effect — it appears to be a core component of MOTS-c's mechanism of action, distinct from and parallel to the AICAR-AMPK axis. A permanently myristoylated MOTS-c, by design anchored to lipid bilayers, would be expected to be physically sequestered at the plasma membrane, ER, or mitochondrial outer membrane, potentially preventing the cytoplasm-to-nucleus transit required for gene-regulatory activity. This represents a genuine biological risk to the modification strategy that the structural prediction cannot resolve — it is a pharmacological question, not a folding question.\n\nThe heuristic property profile is internally consistent with a lipidated peptide: low aggregation propensity reflects the amphipathic character of the molecule (hydrophilic peptide body, hydrophobic myristoyl tail), and the moderate half-life estimate is plausible given that myristoylated peptides are substrates for plasma acylhydrolases and acyl-protein thioesterases. The low BBB score (0.168) is expected and not a primary concern given the target tissues. The stability score of 0.338 is modest, suggesting the modification does not dramatically improve proteolytic resilience — which may be a limitation if DPP-IV or aminopeptidase N activity at the N-terminal Met-1 is a significant degradation route (though the myristoyl amide bond blocks direct aminopeptidase attack on Met-1 itself).\n\nIn aggregate, Fold #25 yields a PROMISING signal on structural grounds — the backbone is preserved, the modification is chemically rational, and the delivery hypothesis addresses a real gap identified in the literature. But the nuclear translocation conflict is a high-priority mechanistic concern that distinguishes this fold from a straightforward uptake-enhancement strategy. The path forward requires either a cleavable linker design that allows myristoyl release after membrane crossing, or direct experimental testing of nuclear localization competence in the myristoylated analog. This fold is best interpreted as establishing the baseline for a lipidation sub-series, not as a standalone validation of the delivery concept.","executive_summary":"Myr-MOTS-c recovers the peptide backbone at moderate confidence (pLDDT 0.63), consistent with prior MOTS-c folds, but the interface score is weak (ipTM 0.21) and no affinity data were produced. The delivery hypothesis is biologically motivated, but permanent membrane anchoring may conflict with MOTS-c's nuclear translocation mechanism — a critical open question.","tweet_draft":"DISTILLATION №25 — promising.\nMOTS-c, N-terminal myristoylation (C14 lipid anchor).\nBackbone pLDDT: 0.63. Interface ipTM: 0.21.\nDelivery hypothesis: plausible. Nuclear trapping risk: unresolved.\nIn silico exploration only. Full report: alembic.bio","research_brief_markdown":"# DISTILLATION №25 — MOTS-c N-Terminal Myristoylation\n**Verdict: PROMISING** | Class: LONGEVITY | Focus: DELIVERY\n**Modified sequence:** Myr-MRWQEMGYIFYPRKLR\n**Target:** AMPKα2 (PRKAA2, UniProt P54646)\n\n---\n\n## Mechanism of Action\n\nMOTS-c (MRWQEMGYIFYPRKLR) is a 16-residue mitochondrial-derived peptide (MDP) encoded within the 12S rRNA region of the human mitochondrial genome. Upon cellular entry, MOTS-c inhibits the folate-methionine cycle in skeletal muscle, causing accumulation of the purine biosynthesis intermediate AICAR (5-aminoimidazole-4-carboxamide ribonucleoside). AICAR is a well-characterized allosteric activator of AMP-activated protein kinase, specifically the AMPKα2 catalytic isoform (PRKAA2) dominant in skeletal muscle and liver. AMPK activation drives GLUT4 translocation to the plasma membrane, enhanced glucose uptake, fatty acid oxidation, and suppression of anabolic pathways — producing the insulin-sensitizing, anti-obesity effects observed in rodent models (Lee et al., PMID:25738459).\n\nA critical secondary mechanism, established by Benayoun & Lee (PMID:31378979), involves **nuclear translocation**: under metabolic stress conditions (glucose deprivation, oxidative stress), MOTS-c translocates from the cytoplasm to the nucleus to directly regulate adaptive gene expression programs. This nuclear function is mechanistically distinct from the cytoplasmic AICAR-AMPK axis and may be equally important to the full therapeutic profile of the peptide. Any modification strategy must account for both arms of this mechanism.\n\nEndogenous MOTS-c circulates in plasma as a hormone-like factor, and its levels decline with aging — consistent with its proposed role in age-related metabolic deterioration. Multiple reviews identify delivery efficiency as the primary translational barrier: native MOTS-c requires high subcutaneous doses (5–10 mg/kg range in rodents) for systemic metabolic benefit, implying suboptimal membrane permeation or bioavailability.\n\n---\n\n## Performance Applications\n\nBased on the established preclinical evidence for native MOTS-c, a successfully delivered, bioactive myristoylated analog could theoretically support:\n\n- **Insulin sensitivity and glucose homeostasis**: The primary validated application — AMPK-driven GLUT4 upregulation in skeletal muscle and liver, relevant to metabolic syndrome, type 2 diabetes, and age-related insulin resistance\n- **Exercise performance and recovery**: AMPK activation in skeletal muscle overlaps with endurance training adaptations; MOTS-c has been studied in the context of physical performance enhancement\n- **Longevity-adjacent metabolic health**: As an endogenous peptide whose levels decline with age, restored MOTS-c signaling is hypothesized to contribute to healthspan extension — the same rationale driving the broader MOTS-c therapeutic development effort\n- **Gestational metabolic support**: A published study (PMID:34798268) demonstrated MOTS-c activity in gestational diabetes models, though this is a specialized clinical context\n\n*All applications are speculative extrapolations from preclinical data. No human clinical data exist for native or modified MOTS-c.*\n\n---\n\n## Modification Rationale\n\nN-terminal myristoylation attaches a 14-carbon saturated fatty acid (myristic acid, C14:0) via a stable amide bond to the alpha-amino group of Met-1. This is the first **lipidation** modification applied to MOTS-c in this lab's distillation series, and the first fold with a **DELIVERY** focus — complementing the prior MOTS-c folds that targeted affinity (Fold #19, K13R) and stability (Fold #5, Met-1 → Norleucine).\n\nNotably, Fold #5 also modified Met-1 — replacing it with Norleucine to eliminate oxidation liability. Fold #25 instead modifies the Met-1 **alpha-amine** while retaining the methionine sidechain, meaning the two folds are chemically distinct despite sharing a common site of intervention. The myristoyl amide bond blocks direct aminopeptidase attack on Met-1, potentially offering a partial oxidation/proteolysis benefit analogous to Fold #5, though this is a secondary effect rather than the primary hypothesis.\n\nThe biological rationale draws on extensive precedent for N-myristoylation as a membrane-anchoring strategy:\n- Myristoylated AKAP inhibitor peptides and PKI fragments show 10–100× improved cellular uptake versus unmodified controls\n- Synthetic myristoylated peptides designed for mitochondrial targeting have been validated as a class\n- Multiple MOTS-c reviews explicitly identify the absence of effective delivery methods as the key gap in clinical translation (PMID:36761202)\n\nThe modification targets the **plasma membrane → cytoplasm** uptake step, hypothesizing that lipid bilayer partitioning driven by the C14 chain will increase the intracellular concentration of MOTS-c in target tissues (skeletal muscle, liver) at lower administered doses.\n\n---\n\n## Predicted Properties — Where the Signal Is Moderate\n\n| Parameter | Value | Interpretation |\n|---|---|---|\n| pLDDT | 0.625 | Moderate backbone confidence — consistent with Folds #5 (0.62) and #19 (0.63) |\n| pTM | 0.535 | Moderate overall structure quality |\n| ipTM | 0.211 | **Weak interface confidence** — model uncertain about peptide-target engagement geometry |\n| Affinity (Boltz-2) | Not produced | Cannot quantify binding change vs. native MOTS-c |\n| Chai-1 agreement | Not produced | No orthogonal structural confirmation |\n| Aggregation propensity | 0.083 | Low — favorable for a lipidated amphipathic species |\n| Stability score | 0.338 | Modest — not a stability-focused modification |\n| BBB penetration | 0.168 | Low — expected and acceptable for peripheral metabolic targets |\n| Half-life estimate | ~30 min–2 hours | Moderate — myristoyl chain susceptible to plasma acylhydrolases |\n\n**What the structural prediction supports**: The 16-residue MOTS-c backbone is recovered at moderate confidence, consistent with the established pattern for this peptide across multiple folds. The myristoyl chain contributes expected low local pLDDT as a flexible aliphatic tail — structurally normal behavior for a disordered hydrophobic appendage in a soluble-state predictor. The C-terminal cationic patch (R12, K13, L14, R16) is structurally preserved, supporting the hypothesis that lipidation does not grossly disrupt the bioactive pharmacophore.\n\n**Where the signal weakens**: The ipTM of 0.21 indicates low confidence in how the myristoylated peptide interfaces with AMPKα2 in the predicted complex. This is consistent with the inherent limitation of applying soluble-state structure predictors to a peptide designed to function at lipid-bilayer interfaces — the relevant biological context (membrane-anchored peptide presenting its C-terminal pharmacophore to a cytoplasmic kinase) is not well-represented by the prediction setup. The weak interface score should not be over-interpreted as evidence of lost binding, but it also cannot be reframed as confidence in retained binding.\n\n---\n\n## What Would Strengthen This Signal\n\n### Immediate in silico next steps\n\n1. **Ensemble prediction**: Run 3–5 independent structure predictions of Myr-MOTS-c to assess reproducibility of the backbone fold and interface geometry. The single-run ipTM of 0.21 has high variance — ensemble averaging would establish whether weak interface confidence is systematic or a run artifact.\n\n2. **Cleavable linker variant**: Design a Myr-[disulfide or ester linker]-MRWQEMGYIFYPRKLR construct where the myristoyl chain is released intracellularly by glutathione or esterases after membrane crossing. Predict the structure of the released (de-myristoylated) peptide. This would directly address the nuclear translocation concern: if the released species is structurally native-like, the delivery hypothesis can be pursued without sacrificing nuclear function.\n\n3. **Direct comparison fold**: Run a matched prediction of Myr-MOTS-c in complex with a nuclear import receptor (importin-α or -β) to assess whether the myristoyl chain structurally occludes the putative NLS-like C-terminal cationic patch. This is speculative but would provide structural data on the nuclear trapping hypothesis.\n\n4. **Palmitoylation (C16) vs. myristoylation (C14) comparison**: A slightly longer acyl chain (palmitoyl) could be tested to determine whether chain length affects predicted backbone quality or interface scores — informing whether C14 is optimal for this peptide geometry.\n\n### Experimental validation priorities\n\n1. **Nuclear localization assay (highest priority)**: GFP-tagged Myr-MOTS-c versus native MOTS-c in skeletal muscle cells under glucose restriction — direct readout of whether myristoylation traps the peptide at the membrane or permits nuclear translocation. This is the critical mechanistic gating experiment.\n\n2. **Cellular uptake quantification**: Fluorescently labeled Myr-MOTS-c vs. native MOTS-c in C2C12 myotubes, with quantitative confocal imaging — validates the core delivery hypothesis.\n\n3. **AMPK activation assay**: p-AMPK/total AMPK ratio at matched concentrations of Myr-MOTS-c vs. native MOTS-c — functional benchmark for whether the modification preserves or ablates the primary metabolic activity.\n\n4. **Plasma stability**: Incubation of Myr-MOTS-c in human plasma with LC-MS/MS monitoring of myristoyl chain integrity — characterizes the lipid anchor stability risk flagged by the heuristic profile.\n\n---\n\n## Lab Context and Cross-Fold Connections\n\nThis fold sits at the intersection of two prior MOTS-c explorations. **Fold #5** (Met-1 → Norleucine, PROMISING, pLDDT 0.62) established that the N-terminus of MOTS-c tolerates structural modification without disrupting the backbone — providing a degree of confidence that the Met-1 site is modifiable. However, Fold #5 replaced the sidechain while leaving the amine free; Fold #25 modifies the amine directly. Whether the alpha-amine modification is equally tolerated remains a structural open question that these two folds together highlight rather than resolve.\n\n**Fold #19** (K13R, PROMISING, pLDDT 0.63) focused on the C-terminal cationic patch — the region hypothesized to mediate AMPK engagement and nuclear localization. The structural preservation of this patch in Fold #25 is reassuring and consistent with the Fold #19 finding that cationic patch modifications are recoverable in prediction. Together, Folds #5, #19, and #25 define a nascent structure-activity map of MOTS-c modifications: N-cap tolerance (Fold #5), cationic patch modifiability (Fold #19), and now N-cap lipidation for delivery (Fold #25).\n\nThe **nuclear translocation concern** raised here has an analog in the FOXO4-DRI series: **Fold #12** (CPP tail truncation, DISCARDED) demonstrated that modifications to the cell-penetrating/nuclear-targeting region of a peptide can abolish predicted complex formation. MOTS-c's situation is mechanistically inverted — the concern is not that the NLS-like C-terminal patch is being modified, but that the N-terminal lipid anchor may physically prevent the nuclear import process. The lesson from Fold #12 applies: delivery-focused modifications must not inadvertently compromise the nuclear targeting that makes the peptide functional.\n\n---\n\n*All structural data are in silico predictions from a single model run. Heuristic property estimates are sequence-based approximations, not experimentally derived values. This is research, not medical advice.*","structural_caption":"The 16-residue MOTS-c backbone is recovered with moderate local confidence, consistent with the expectation that lipidation does not grossly disrupt the peptide fold. However, the predicted peptide-target interface is weak (ipTM 0.21), suggesting the model is not confident about how the myristoylated peptide engages its partner. The myristoyl chain is expected to contribute low local pLDDT as a flexible aliphatic tail, which is structurally normal but limits what can be concluded about membrane-anchoring geometry from a soluble-state predictor. No affinity prediction was produced, so binding strength relative to native MOTS-c cannot be quantified here.","key_findings_summary":"MOTS-c is a 16-amino-acid mitochondrial-derived peptide (MDP) encoded within the 12S rRNA region of the mitochondrial genome. The foundational 2015 study by Lee et al. (PMID:25738459) established that MOTS-c's primary target organ is skeletal muscle, where it inhibits the folate-methionine cycle, leading to AICAR accumulation and downstream AMPK activation. This mechanism drives improvements in insulin sensitivity, glucose uptake (via GLUT4 regulation), and metabolic homeostasis. In vivo, exogenous MOTS-c administration prevented age-dependent and high-fat-diet-induced insulin resistance and obesity in mice, establishing strong preclinical proof-of-concept for therapeutic delivery of this peptide.\n\nMultiple review papers (PMID:36677050, PMID:36761202) confirm that MOTS-c activates the AICAR-AMPK signaling axis as its dominant metabolic mechanism, with downstream effects on GLUT4, STAT3, and IL-10 gene expression. The peptide is secreted into plasma, circulates as a hormone-like factor, and its levels decline with age — a pattern consistent with its proposed role in age-related metabolic decline. Beyond metabolism, MOTS-c has demonstrated activity in bone remodeling (PMID:37200834), gestational diabetes (PMID:34798268), ovarian cancer suppression (PMID:39321430), and potential cardioprotection (DOI:10.20944/preprints202604.0328.v1). The breadth of activity underscores the peptide's pleiotropic signaling role, but also raises questions about target engagement specificity relevant to any modified analog.\n\nA critical mechanistic nuance identified by Benayoun & Lee (PMID:31378979) is that MOTS-c translocates to the nucleus under metabolic stress conditions (glucose restriction, oxidative stress) to directly regulate adaptive nuclear gene expression. This nuclear translocation suggests that the bioactive form of MOTS-c must be cytosolic/nuclear-accessible, not simply membrane-associated. The C-terminal cationic region of MOTS-c has been implicated in cellular uptake and AMPK engagement, while the N-terminus (Met-1) is less characterized as a pharmacophore. Whether N-terminal modification interferes with the nuclear translocation mechanism or any upstream receptor/transporter engagement remains entirely uncharacterized in the published literature.\n\nWith respect to the proposed N-terminal myristoylation strategy, there is no published literature directly addressing lipidation of MOTS-c in any form. The hypothesis draws on general precedents for N-myristoylation as a membrane-anchoring strategy, which is well-validated in the broader peptide/protein field. The gestational diabetes study (PMID:34798268) and the original metabolic study (PMID:25738459) both used systemic (likely intraperitoneal) injection of native MOTS-c and achieved tissue-level effects, suggesting the native peptide does reach skeletal muscle despite its hydrophilic character — though the efficiency of this uptake is unknown. The ME/CFS preprints (DOI:10.20944/preprints202507.0058.v1 and v2) note that no human safety or efficacy data exist, highlighting the early stage of MOTS-c therapeutic development overall.\n\nThe literature does not directly characterize which specific residues of MOTS-c are required for AMPK activation, making it difficult to predict with confidence whether Met-1 modification is tolerated. The C-terminal cationic patch (R12-K13-L14-R16) implicated in the hypothesis is consistent with what is known about membrane-permeating and nuclear-targeting peptide motifs, but direct mutagenesis or SAR (structure-activity relationship) data for MOTS-c are absent from the available abstracts. This is a significant gap: any myristoylated analog must be benchmarked against native MOTS-c for AMPK activation and nuclear translocation competence."},"structured":{"known_activity":null,"known_binders":null,"candidate_variants":null,"domain_annotations":null,"literature_context":{"pubmed":[{"pmid":"36677050","title":"MOTS-c Functionally Prevents Metabolic Disorders.","abstract":"Mitochondrial-derived peptides are a family of peptides encoded by short open reading frames in the mitochondrial genome, which have regulatory effects on mitochondrial functions, gene expression, and metabolic homeostasis of the body. As a new member of the mitochondrial-derived peptide family, mitochondrial open reading frame of the 12S rRNA-c (MOTS-c) is regarding a peptide hormone that could reduce insulin resistance, prevent obesity, improve muscle function, promote bone metabolism, enhance immune regulation, and postpone aging. MOTS-c plays these physiological functions mainly through activating the AICAR-AMPK signaling pathways by disrupting the folate-methionine cycle in cells. Recent studies have shown that the above hormonal effect can be achieved through MOTS-c regulating the expression of genes such as GLUT4, STAT3, and IL-10. However, there is a lack of articles summarizing the genes and pathways involved in the physiological activity of MOTS-c. This article aims to summarize and interpret the interesting and updated findings of MOTS-c-associated genes and pathways involved in pathological metabolic processes. Finally, it is expected to develop novel diagnostic markers and treatment approaches with MOTS-c to prevent and treat metabolic disorders in the future.","authors":["Gao Yue","Wei Xinran","Wei Pingying","Lu Huijie","Zhong Luying","Tan Jie","Liu Hongbo","Liu Zheng"],"year":2023,"journal":"Metabolites"},{"pmid":"36761202","title":"MOTS-c: A promising mitochondrial-derived peptide for therapeutic exploitation.","abstract":"Mitochondrial ORF of the 12S rRNA Type-C (MOTS-c) is a mitochondrial-derived peptide composed of 16 amino acids encoded by the 12S rRNA region of the mitochondrial genome. The MOTS-c protein is transferred to the nucleus during metabolic stress and directs the expression of nuclear genes to promote cell balance. Different tissues co-expressed the protein with mitochondria, and plasma also contained the protein, but its level decreased with age. In addition, MOTS-c has been shown to improve glucose metabolism in skeletal muscle, which indicates its benefits for diseases such as diabetes, obesity, and aging. Nevertheless, MOTS-c has been used less frequently in disease treatment, and no effective method of applying MOTS-c in the clinic has been developed. Throughout this paper, we discussed the discovery and physiological function of mitochondrial-derived polypeptide MOTS-c, and the application of MOTS-c in the treatment of various diseases, such as aging, cardiovascular disease, insulin resistance, and inflammation. To provide additional ideas for future research and development, we tapped into the molecular mechanisms and therapeutic potentials of MOTS-c to improve diseases and combined the technology with synthetic biology in order to offer a new approach to its development and application.","authors":["Zheng Yuejun","Wei Zilin","Wang Tianhui"],"year":2023,"journal":"Frontiers in endocrinology"},{"pmid":"31378979","title":"MOTS-c: A Mitochondrial-Encoded Regulator of the Nucleus.","abstract":"Mitochondria are increasingly being recognized as information hubs that sense cellular changes and transmit messages to other cellular components, such as the nucleus, the endoplasmic reticulum (ER), the Golgi apparatus, and lysosomes. Nonetheless, the interaction between mitochondria and the nucleus is of special interest because they both host part of the cellular genome. Thus, the communication between genome-bearing organelles would likely include gene expression regulation. Multiple nuclear-encoded proteins have been known to regulate mitochondrial gene expression. On the contrary, no mitochondrial-encoded factors are known to actively regulate nuclear gene expression. MOTS-c (mitochondrial open reading frame of the 12S ribosomal RNA type-c) is a recently identified peptide encoded within the mitochondrial 12S ribosomal RNA gene that has metabolic functions. Notably, MOTS-c can translocate to the nucleus upon metabolic stress (e.g., glucose restriction and oxidative stress) and directly regulate adaptive nuclear gene expression to promote cellular homeostasis. It is hypothesized that cellular fitness requires the coevolved mitonuclear genomes to coordinate adaptive responses using gene-encoded factors that cross-regulate the opposite genome. This suggests that cellular gene expression requires the bipartite split genomes to operate as a unified system, rather than the nucleus being the sole master regulator.","authors":["Benayoun Bérénice A","Lee Changhan"],"year":2019,"journal":"BioEssays : news and reviews in molecular, cellular and developmental biology"},{"pmid":"25738459","title":"The mitochondrial-derived peptide MOTS-c promotes metabolic homeostasis and reduces obesity and insulin resistance.","abstract":"Mitochondria are known to be functional organelles, but their role as a signaling unit is increasingly being appreciated. The identification of a short open reading frame (sORF) in the mitochondrial DNA (mtDNA) that encodes a signaling peptide, humanin, suggests the possible existence of additional sORFs in the mtDNA. Here we report a sORF within the mitochondrial 12S rRNA encoding a 16-amino-acid peptide named MOTS-c (mitochondrial open reading frame of the 12S rRNA-c) that regulates insulin sensitivity and metabolic homeostasis. Its primary target organ appears to be the skeletal muscle, and its cellular actions inhibit the folate cycle and its tethered de novo purine biosynthesis, leading to AMPK activation. MOTS-c treatment in mice prevented age-dependent and high-fat-diet-induced insulin resistance, as well as diet-induced obesity. These results suggest that mitochondria may actively regulate metabolic homeostasis at the cellular and organismal level via peptides encoded within their genome.","authors":["Lee Changhan","Zeng Jennifer","Drew Brian G","Sallam Tamer","Martin-Montalvo Alejandro","Wan Junxiang","Kim Su-Jeong","Mehta Hemal","Hevener Andrea L","de Cabo Rafael","Cohen Pinchas"],"year":2015,"journal":"Cell metabolism"},{"pmid":"37307934","title":"MOTS-c: A potential anti-pulmonary fibrosis factor derived by mitochondria.","abstract":"Pulmonary fibrosis (PF) is a serious lung disease characterized by diffuse alveolitis and disruption of alveolar structure, with a poor prognosis and unclear etiopathogenesis. While ageing, oxidative stress, metabolic disorders, and mitochondrial dysfunction have been proposed as potential contributors to the development of PF, effective treatments for this condition remain elusive. However, Mitochondrial open reading frame of the 12S rRNA-c (MOTS-c), a peptide encoded by the mitochondrial genome, has shown promising effects on glucose and lipid metabolism, cellular and mitochondrial homeostasis, as well as the reduction of systemic inflammatory responses, and is being investigated as a potential exercise mimetic. Additionally, dynamic expression changes of MOTS-c have been closely linked to ageing and ageing-related diseases, indicating its potential as an exercise mimetic. Therefore, the review aims to comprehensively analyze the available literature on the potential role of MOTS-c in improving PF development and to identify specific therapeutic targets for future treatment strategies.","authors":["Zhang Zewei","Chen Dongmei","Du Kaili","Huang Yaping","Li Xingzhe","Li Quwen","Lv Xiaoting"],"year":2023,"journal":"Mitochondrion"},{"pmid":"39321430","title":"Mitochondrial-Derived Peptide MOTS-c Suppresses Ovarian Cancer Progression by Attenuating USP7-Mediated LARS1 Deubiquitination.","abstract":"Mitochondrial-nuclear communication plays a vital role in maintaining cellular homeostasis. MOTS-c, a short peptide derived from the 12S rRNA of mitochondrial DNA, has been suggested as a retrograde mitochondrial signal. Although recent clinical studies have suggested a possible link between MOTS-c and human cancer, the role of MOTS-c in tumorigenesis has yet to be investigated. Here, MOTS-c levels are found to be reduced in both serum and tumor tissues from ovarian cancer (OC) patients, which are associated with poor patients' prognosis. Exogenous MOTS-c inhibits the proliferation, migration and invasion of OC cells, and induces cell cycle arrest and apoptosis. Mechanistically, MOTS-c interacts with LARS1 and promotes its ubiquitination and proteasomal degradation. In addition, USP7 was identified as a deubiquitinase of LARS1, and MOTS-c can attenuates USP7-mediated LARS1 deubiquitination by competing with USP7 for binding to LARS1. Besides, LARS1 was found to be increased and play an important oncogenic function in OC. More importantly, MOTS-c displays a marked anti-tumor effect on OC growth without systemic toxicity in vivo. In conclusion, this study reveals a crucial role of MOTS-c in OC and provides a possibility for MOTS-c as a therapeutic target for the treatment of this manlignacy.","authors":["Yin Yadong","Li Yujie","Ma Boyi","Ren Chenlu","Zhao Shuhua","Li Jia","Gong Yun","Yang Hong","Li Jibin"],"year":2024,"journal":"Advanced science (Weinheim, Baden-Wurttemberg, Germany)"},{"pmid":"37200834","title":"Role of MOTS-c in the regulation of bone metabolism.","abstract":"MOTS-c, a mitochondrial-derived peptide (MDP), is an essential regulatory mediator of cell protection and energy metabolism and is involved in the development of specific diseases. Recent studies have revealed that MOTS-c promotes osteoblast proliferation, differentiation, and mineralization. Furthermore, it inhibits osteoclast production and mediates the regulation of bone metabolism and bone remodeling. Exercise effectively upregulates the expression of MOTS-c, but the specific mechanism of MOTS-c regulation in bone by exercise remains unclear. Therefore, this article reviewed the distribution and function of MOTS-c in the tissue, discussed the latest research developments in the regulation of osteoblasts and osteoclasts, and proposed potential molecular mechanisms for the effect of exercise on the regulation of bone metabolism. This review provides a theoretical reference for establishing methods to prevent and treat skeletal metabolic diseases.","authors":["Yi Xuejie","Hu Guangxuan","Yang Yang","Li Jing","Jin Junjie","Chang Bo"],"year":2023,"journal":"Frontiers in physiology"},{"pmid":"34798268","title":"The mitochondrial-derived peptide MOTS-c relieves hyperglycemia and insulin resistance in gestational diabetes mellitus.","abstract":"The most common complication during pregnancy, gestational diabetes mellitus (GDM), can cause adverse pregnancy outcomes and result in the mother and infant having a higher risk of developing type 2 diabetes after pregnancy. However, existing therapies for GDM remain scant, with the most common being lifestyle intervention and appropriate insulin treatment. MOTS-c, a mitochondrial-derived peptide, can target skeletal muscle and enhance glucose metabolism. Here, we demonstrate that MOTS-c can be an effective treatment for GDM. A GDM mouse model was established by short term high-fat diet combined with low-dose streptozotocin (STZ) treatment while MOTS-c was administrated daily during pregnancy. GDM symptoms such as blood glucose and insulin levels, glucose and insulin tolerance, as well as reproductive outcomes were investigated. MOTS-c significantly alleviated hyperglycemia, improved insulin sensitivity and glucose tolerance, and reduced birth weight and the death of offspring induced by GDM. Similar to a previous study, MOTS-c also could activate insulin sensitivity in the skeletal muscle of GDM mice and elevate glucose uptake in vitro. In addition, we found that MOTS-c protects pancreatic β-cell from STZ-mediated injury. Taken together, our findings demonstrate that MOTS-c could be a promising strategy for the treatment of GDM.","authors":["Yin Yadong","Pan Yihui","He Jin","Zhong Hong","Wu Yangyang","Ji Chenbo","Liu Lan","Cui Xianwei"],"year":2022,"journal":"Pharmacological research"}],"biorxiv":[{"pmid":"","doi":"10.20944/preprints202604.0328.v1","title":"Humanin and MOTS-c Attenuate Atrial Fibrillation by Suppressing Fibrosis and Mitochondrial Dysfunction","abstract":"A single paragraph of about 200 words maximum. For research articles, abstracts should give a pertinent overview of the work. We strongly encourage authors to use the following style of structured abstracts, but without headings: (1) Background: Place the question addressed in a broad context and highlight the purpose of the study; (2) Methods: briefly describe the main methods or treatments applied; (3) Results: summarize the article’s main findings; (4) Conclusions: indicate the main conclusions or interpretations. The abstract should be an objective representation of the article and it must not contain results that are not presented and substantiated in the main text and should not exaggerate the main conclusions.","authors":["Liao Y","Xu J","Jiao Y","Sun X","Gao M","Ding Y","Cai D","Shen Y","Zhou X","Han W."],"year":2026,"journal":"PPR","source":"PPR","preprint":true},{"pmid":"","doi":"10.20944/preprints202507.0058.v2","title":"Redefining Mitochondrial Therapy for ME/CFS: The Case for MOTS-c","abstract":"Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a debilitating, multi-system disease characterized by profound fatigue, post-exertional malaise (PEM), and a constellation of immune, neurological, and autonomic symptoms. Despite its global prevalence, the pathophysiology of ME/CFS remains elusive, and there are no FDA-approved treatments targeting the underlying mechanisms. Symptom-based pharmacologic management is often complicated by hypersensitivity reactions and mitochondrial toxicity. Non-pharmacologic interventions, such as energy conservation, autonomic regulation, and nutritional strategies, are frequently employed to mitigate symptom burden. Emerging research points to mitochondrial dysfunction as a core contributor to ME/CFS pathology, marked by impaired ATP production, oxidative stress, and bioenergetic failure. Mitochondrial-derived peptides (MDPs), particularly MOTS-c, offer a novel therapeutic avenue by enhancing mitochondrial biogenesis, reducing oxidative damage, and modulating inflammatory responses through AMPK and NRF2 activation. Preclinical evidence suggests that MOTS-c improves glucose metabolism, increases mitochondrial density, and enhances fatigue resistance. However, safety and efficacy data in humans are lacking. Future investigations are needed to evaluate MOTS-c's potential as a disease-modifying therapy in ME/CFS.","authors":["Cheema AK","Tehrani L","Patel S","Rozenfeld I","Renesca V","Fornos A","Kempuraj D","Klimas NG."],"year":2025,"journal":"PPR","source":"PPR","preprint":true},{"pmid":"","doi":"10.20944/preprints202507.0058.v1","title":"Redefining Mitochondrial Therapy for ME/CFS: The Case for MOTS-c","abstract":"Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a debilitating, multi-system disease characterized by profound fatigue, post-exertional malaise (PEM), and a constellation of immune, neurological, and autonomic symptoms. Despite its global prevalence, the pathophysiology of ME/CFS remains elusive, and there are no FDA-approved treatments targeting the underlying mechanisms. Symptom-based pharmacologic management is often complicated by hypersensitivity reactions and mitochondrial toxicity. Non-pharmacologic interventions, such as energy conservation, autonomic regulation, and nutritional strategies, are frequently employed to mitigate symptom burden. Emerging research points to mitochondrial dysfunction as a core contributor to ME/CFS pathology, marked by impaired ATP production, oxidative stress, and bioenergetic failure. Mitochondrial-derived peptides (MDPs), particularly MOTS-c, offer a novel therapeutic avenue by enhancing mitochondrial biogenesis, reducing oxidative damage, and modulating inflammatory responses through AMPK and NRF2 activation. Preclinical evidence suggests that MOTS-c improves glucose metabolism, increases mitochondrial density, and enhances fatigue resistance. However, safety and efficacy data in humans are lacking. Future investigations are needed to evaluate MOTS-c's potential as a disease-modifying therapy in ME/CFS.","authors":["Cheema AK","Tehrani L","Patel S","Rozenfeld I","Renesca V","Fornos A","Kempuraj D","Klimas NG."],"year":2025,"journal":"PPR","source":"PPR","preprint":true}],"preprints":[{"pmid":"","doi":"10.20944/preprints202604.0328.v1","title":"Humanin and MOTS-c Attenuate Atrial Fibrillation by Suppressing Fibrosis and Mitochondrial Dysfunction","abstract":"A single paragraph of about 200 words maximum. For research articles, abstracts should give a pertinent overview of the work. We strongly encourage authors to use the following style of structured abstracts, but without headings: (1) Background: Place the question addressed in a broad context and highlight the purpose of the study; (2) Methods: briefly describe the main methods or treatments applied; (3) Results: summarize the article’s main findings; (4) Conclusions: indicate the main conclusions or interpretations. The abstract should be an objective representation of the article and it must not contain results that are not presented and substantiated in the main text and should not exaggerate the main conclusions.","authors":["Liao Y","Xu J","Jiao Y","Sun X","Gao M","Ding Y","Cai D","Shen Y","Zhou X","Han W."],"year":2026,"journal":"PPR","source":"PPR","preprint":true},{"pmid":"","doi":"10.20944/preprints202507.0058.v2","title":"Redefining Mitochondrial Therapy for ME/CFS: The Case for MOTS-c","abstract":"Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a debilitating, multi-system disease characterized by profound fatigue, post-exertional malaise (PEM), and a constellation of immune, neurological, and autonomic symptoms. Despite its global prevalence, the pathophysiology of ME/CFS remains elusive, and there are no FDA-approved treatments targeting the underlying mechanisms. Symptom-based pharmacologic management is often complicated by hypersensitivity reactions and mitochondrial toxicity. Non-pharmacologic interventions, such as energy conservation, autonomic regulation, and nutritional strategies, are frequently employed to mitigate symptom burden. Emerging research points to mitochondrial dysfunction as a core contributor to ME/CFS pathology, marked by impaired ATP production, oxidative stress, and bioenergetic failure. Mitochondrial-derived peptides (MDPs), particularly MOTS-c, offer a novel therapeutic avenue by enhancing mitochondrial biogenesis, reducing oxidative damage, and modulating inflammatory responses through AMPK and NRF2 activation. Preclinical evidence suggests that MOTS-c improves glucose metabolism, increases mitochondrial density, and enhances fatigue resistance. However, safety and efficacy data in humans are lacking. Future investigations are needed to evaluate MOTS-c's potential as a disease-modifying therapy in ME/CFS.","authors":["Cheema AK","Tehrani L","Patel S","Rozenfeld I","Renesca V","Fornos A","Kempuraj D","Klimas NG."],"year":2025,"journal":"PPR","source":"PPR","preprint":true},{"pmid":"","doi":"10.20944/preprints202507.0058.v1","title":"Redefining Mitochondrial Therapy for ME/CFS: The Case for MOTS-c","abstract":"Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a debilitating, multi-system disease characterized by profound fatigue, post-exertional malaise (PEM), and a constellation of immune, neurological, and autonomic symptoms. Despite its global prevalence, the pathophysiology of ME/CFS remains elusive, and there are no FDA-approved treatments targeting the underlying mechanisms. Symptom-based pharmacologic management is often complicated by hypersensitivity reactions and mitochondrial toxicity. Non-pharmacologic interventions, such as energy conservation, autonomic regulation, and nutritional strategies, are frequently employed to mitigate symptom burden. Emerging research points to mitochondrial dysfunction as a core contributor to ME/CFS pathology, marked by impaired ATP production, oxidative stress, and bioenergetic failure. Mitochondrial-derived peptides (MDPs), particularly MOTS-c, offer a novel therapeutic avenue by enhancing mitochondrial biogenesis, reducing oxidative damage, and modulating inflammatory responses through AMPK and NRF2 activation. Preclinical evidence suggests that MOTS-c improves glucose metabolism, increases mitochondrial density, and enhances fatigue resistance. However, safety and efficacy data in humans are lacking. Future investigations are needed to evaluate MOTS-c's potential as a disease-modifying therapy in ME/CFS.","authors":["Cheema AK","Tehrani L","Patel S","Rozenfeld I","Renesca V","Fornos A","Kempuraj D","Klimas NG."],"year":2025,"journal":"PPR","source":"PPR","preprint":true}],"consensus_view":"The literature consensus strongly supports MOTS-c as a biologically active peptide that activates AMPK through a folate cycle-AICAR mechanism in skeletal muscle, with confirmed in vivo metabolic benefits when administered exogenously in rodent models. The consensus also recognizes the dual cytoplasmic/nuclear localization of MOTS-c as essential to its function. However, there is no consensus — nor any published data — on chemical modification of MOTS-c, lipidation strategies, or structure-activity relationships. The field has not yet characterized the minimal pharmacophore or identified which residues are dispensable for AMPK engagement. Delivery challenges are acknowledged across multiple reviews, but no modified analog has been published. The evidence base is entirely preclinical (rodent models and cell lines), with zero human clinical data, making the overall evidence level moderate-to-low for therapeutic translation of any MOTS-c analog.","knowledge_gaps":"1) No SAR (structure-activity relationship) data exist for MOTS-c — it is unknown whether Met-1 is part of the pharmacophore or freely modifiable. 2) The molecular mechanism by which extracellular/exogenous MOTS-c enters cells is unknown (receptor-mediated, transporter, or direct membrane permeation) — this is critical for predicting whether myristoylation helps or redirects uptake. 3) The nuclear translocation signal within MOTS-c has not been mapped to specific residues; whether N-terminal modification blocks nuclear import is unstudied. 4) No lipidated MOTS-c analog (myristoylated or otherwise) has been synthesized or tested in any published study. 5) The pharmacokinetics (half-life, tissue distribution, clearance) of native MOTS-c after systemic administration are poorly characterized, making it difficult to establish the PK baseline the modification intends to improve. 6) The specific molecular interaction between MOTS-c and the AMPK complex (AMPKα2 or scaffold subunits) has not been structurally characterized, so the role of the C-terminal cationic patch in AMPK binding is inferential.","supporting_evidence":"1) MOTS-c's primary metabolic target tissue is skeletal muscle (PMID:25738459), and the liver is also implicated — both tissues are metabolically active and highly amenable to lipid-anchored peptide uptake via membrane partitioning. 2) The AICAR-AMPK axis is well-established as MOTS-c's mechanism (PMID:25738459, PMID:36677050), and AMPKα2 is the dominant catalytic isoform in skeletal muscle and liver, consistent with the target. 3) Multiple studies confirm exogenous MOTS-c administration is pharmacologically active, establishing that the peptide survives in vivo handling and reaches intracellular targets — a lipidated version with improved membrane association could plausibly enhance this uptake efficiency. 4) The C-terminal cationic residues (RKLR region) are structurally analogous to cell-penetrating peptide motifs and nuclear localization signals, supporting the hypothesis that this region mediates functional engagement and should be preserved. 5) N-myristoylation as a strategy for mitochondrial membrane anchoring and enhanced cellular uptake has precedent in the broader MDP/therapeutic peptide field, even if not demonstrated for MOTS-c specifically. 6) Reviews (PMID:36761202) explicitly identify the absence of effective delivery methods as the key gap in MOTS-c clinical translation, validating the motivation for the modification.","challenging_evidence":"1) MOTS-c undergoes nuclear translocation as a key part of its mechanism of action (PMID:31378979). A myristoylated peptide, by design, would be anchored to lipid membranes (plasma membrane, ER, mitochondrial outer membrane), potentially preventing the cytoplasm-to-nucleus transit required for gene-regulatory activity. This is a fundamental mechanistic conflict with the hypothesis. 2) Native MOTS-c is biologically active when delivered systemically in rodents (PMID:25738459, PMID:34798268), suggesting the unmodified peptide achieves sufficient intracellular bioavailability for therapeutic effect — the degree to which improved membrane association is actually rate-limiting is not established. 3) Myristoylation of the N-terminal Met-1 adds a bulky C14 hydrophobic chain adjacent to the peptide backbone; if any N-terminal residues are involved in protein-protein interactions (e.g., with LARS1 as shown in PMID:39321430, or with AMPK subunits), steric occlusion could ablate activity. 4) Improved membrane association from myristoylation may dramatically alter biodistribution — preferential partitioning into lipid-rich tissues (adipose, myelin-rich neural tissue) rather than the intended skeletal muscle/liver targets could reduce on-target potency. 5) Myristoylated peptides are substrates for acyl-protein thioesterases and other lipases; metabolic instability of the lipid anchor in plasma or intracellularly could yield unpredictable PK. 6) The preprint evidence (DOI:10.20944/preprints202507.0058) is non-peer-reviewed and the atrial fibrillation preprint abstract is entirely uninformative, limiting confidence in the broader activity landscape. The overall evidence base is thin, meaning both the hypothesis and challenges are largely inferential."},"caveats":["in silico prediction only — requires wet lab validation","single-run prediction (not ensembled); ipTM of 0.21 has high variance and should not be interpreted as definitive evidence of weakened or preserved binding","predicted properties may not reflect real-world biological behavior","this is research, not medical advice","soluble-state structure predictors are not optimized for lipidated, membrane-anchored peptides — the biological context (bilayer-tethered peptide engaging a cytoplasmic kinase) is not well-represented by the prediction setup","no Boltz-2 affinity values or Chai-1 agreement scores were produced — binding change relative to native MOTS-c cannot be quantified from this fold","heuristic property estimates (aggregation, stability, BBB, half-life) are sequence-based approximations, not experimentally derived values","the nuclear translocation conflict (myristoyl anchor vs. cytoplasm-to-nucleus transit) is a pharmacological hypothesis that structural prediction cannot resolve — experimental nuclear localization assays are required before this modification can be validated as delivery-compatible","no SAR data exist for MOTS-c — whether Met-1 alpha-amine modification is tolerated for AMPK activation is entirely unknown from the published literature","myristoyl chain susceptibility to plasma acylhydrolases and acyl-protein thioesterases introduces metabolic instability risk not captured by the heuristic half-life estimate"],"works_cited":[{"pmid_or_doi":"25738459","title":"The mitochondrial-derived peptide MOTS-c promotes metabolic homeostasis and reduces obesity and insulin resistance","year":2015,"relevance":"Foundational discovery paper establishing MOTS-c's primary mechanism — AMPK activation via folate cycle inhibition in skeletal muscle — and demonstrating in vivo metabolic benefit with exogenous peptide treatment, directly relevant to the therapeutic target and tissue tropism in our hypothesis."},{"pmid_or_doi":"31378979","title":"MOTS-c: A Mitochondrial-Encoded Regulator of the Nucleus","year":2019,"relevance":"Establishes that MOTS-c must translocate to the nucleus under metabolic stress to exert gene-regulatory functions, raising the critical question of whether membrane-anchoring via myristoylation would sequester the peptide and prevent this necessary nuclear trafficking."},{"pmid_or_doi":"36677050","title":"MOTS-c Functionally Prevents Metabolic Disorders","year":2023,"relevance":"Comprehensive review confirming AICAR-AMPK as the dominant signaling axis and identifying GLUT4 and related genes as downstream targets in skeletal muscle and liver — the same target tissues and pathway addressed by our hypothesis."},{"pmid_or_doi":"36761202","title":"MOTS-c: A promising mitochondrial-derived peptide for therapeutic exploitation","year":2023,"relevance":"Highlights that no effective clinical delivery method for MOTS-c has been developed, directly motivating the myristoylation strategy, while also noting the peptide's co-expression with mitochondria across tissues and its age-dependent plasma decline."},{"pmid_or_doi":"34798268","title":"The mitochondrial-derived peptide MOTS-c relieves hyperglycemia and insulin resistance in gestational diabetes mellitus","year":2022,"relevance":"Demonstrates that systemically administered native MOTS-c reaches skeletal muscle and activates insulin sensitivity in vivo, providing a baseline against which the membrane-permeability improvement from myristoylation can be benchmarked."},{"pmid_or_doi":"37200834","title":"Role of MOTS-c in the regulation of bone metabolism","year":2023,"relevance":"Confirms MOTS-c's tissue distribution beyond skeletal muscle and its energy metabolism regulatory role, relevant to assessing off-target distribution risks of a lipidated analog with altered pharmacokinetics."},{"pmid_or_doi":"37307934","title":"MOTS-c: A potential anti-pulmonary fibrosis factor derived by mitochondria","year":2023,"relevance":"Discusses MOTS-c's role in mitochondrial homeostasis and its exercise-mimetic properties via AMPK, adding context to the breadth of AMPK-mediated benefits and the importance of preserving this signaling competence in modified analogs."},{"pmid_or_doi":"39321430","title":"Mitochondrial-Derived Peptide MOTS-c Suppresses Ovarian Cancer Progression by Attenuating USP7-Mediated LARS1 Deubiquitination","year":2024,"relevance":"Reveals a protein-protein interaction mechanism (MOTS-c binding to LARS1) independent of AMPK, suggesting the peptide has a complex, conformation-dependent interaction surface — N-terminal modification could potentially alter these binding interfaces."},{"pmid_or_doi":"10.20944/preprints202507.0058.v2","title":"Redefining Mitochondrial Therapy for ME/CFS: The Case for MOTS-c","year":2025,"relevance":"Preprint (not peer-reviewed) noting absence of human safety and efficacy data for MOTS-c; supports the translational motivation for improved delivery strategies like myristoylation to enhance bioavailability and potency."},{"pmid_or_doi":"10.20944/preprints202604.0328.v1","title":"Humanin and MOTS-c Attenuate Atrial Fibrillation by Suppressing Fibrosis and Mitochondrial Dysfunction","year":2026,"relevance":"Preprint (not peer-reviewed, abstract uninformative) suggesting MOTS-c has cardioprotective effects; relevant to assessing whether lipidation-altered biodistribution could have unintended cardiac effects."}]},"onchain":{"hash":"2gPCifnMWvNiGf33noGg8gmQSSZeBPtDomWGgQq7myu4nYyTGHAsKfMghGQXeuVvcdddoEJeZjdvjiH5AXXLshWG","signature":"2gPCifnMWvNiGf33noGg8gmQSSZeBPtDomWGgQq7myu4nYyTGHAsKfMghGQXeuVvcdddoEJeZjdvjiH5AXXLshWG","data_hash":"470c583987edb01dc0ae1f7c40a197a27bc728aced67d9270618bf25e2534c6b","logged_at":"2026-05-03T05:02:49.156377+00:00","explorer_url":"https://solscan.io/tx/2gPCifnMWvNiGf33noGg8gmQSSZeBPtDomWGgQq7myu4nYyTGHAsKfMghGQXeuVvcdddoEJeZjdvjiH5AXXLshWG"},"ipfs_hash":null,"created_at":"2026-05-03T04:41:05.848000+00:00","updated_at":"2026-05-03T05:02:49.161061+00:00"}