{"id":30,"slug":"30-mots-c-all-hydrocarbon-i-i-4-staple-between-positions-5-and-9-met-5","title":"MOTS-c i,i+4 stapled helix (Glu-5/Lys-9) to lock AMPK-engaging conformation","status":"DISCARDED","fold_verdict":"DISCARDED","discard_reason":null,"peptide":{"name":"MOTS-c","class":"LONGEVITY","sequence":"MRWQEMGYIFYPRKLR","modified_sequence":"MRWQE[S5]GYI[S5]FYPRKLR","modification_description":"All-hydrocarbon i,i+4 staple between positions 5 and 9: Met-5 → (S)-2-(4'-pentenyl)alanine (S5) and Tyr-9 → (S)-2-(4'-pentenyl)alanine (S5), followed by ruthenium-catalyzed ring-closing metathesis to form a covalent hydrocarbon bridge across one helical turn"},"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 an i,i+4 all-hydrocarbon staple between positions 5 and 9 of MOTS-c will pre-organize the central segment into a single helical turn, stabilizing the bioactive conformation that engages the AMPK alpha-2 regulatory interface. The staple is placed on the solvent-exposed face (Met-5/Tyr-9), leaving the cationic C-terminal patch (R12-K13-R16, the AMPK-engaging surface validated in Fold #19) and aromatic Trp-3/Phe-10 unperturbed. We predict a measurable increase in helical content and improved structural confidence over the largely disordered native peptide (pLDDT ~0.62).","rationale":"MOTS-c is short (16 aa) and predicted as low-confidence/disordered in prior folds (pLDDT 0.62-0.63), suggesting conformational entropy is a major barrier to high-affinity AMPK engagement. Hydrocarbon stapling at i,i+4 is the canonical approach to enforce a single helical turn without altering side-chain chemistry at the binding face. Met-5 is also an oxidation liability (parallel to the Nle rationale of Fold #5), so converting it to a non-oxidizable stapling residue is a two-for-one. This diverges from the last 3 folds (Tesamorelin: non-canonical AA / STABILITY; TB-500: lactam cyclization / CONFORMATION but different peptide and chemistry; FOXO4-DRI: lipidation / PK) — stapled peptide chemistry has not appeared in the recent lab-wide history, and CONFORMATION via hydrocarbon staple is a distinct strategy from TB-500's lactam.","predicted_outcome":"AlphaFold should predict a more defined α-helical segment spanning residues 5-9 with elevated local pLDDT (>0.70 in the stapled region), while the C-terminal cationic tail remains flexible. Overall pLDDT should improve modestly vs. native (target >0.65). The Trp-3, Phe-10, and R12/K13/R16 side chains should remain solvent-accessible for receptor engagement.","mechanism_class":null,"biohacker_use":null},"confidence":{"plddt":0.6038647294044495,"ptm":0.5655404925346375,"iptm":0.22726136445999146,"chai_agreement":null,"chai1_gated_decision":"RAN_BORDERLINE","binding_probability":null,"binding_pic50":null,"predicted_binding_change":null},"profile":{"aggregation_propensity":0.054,"stability_score":0.461,"bbb_penetration_score":0.126,"half_life_estimate":"moderate (~30 minutes – 2 hours)"},"narrative":{"tldr":"DISTILLATION №30 tests an all-hydrocarbon i,i+4 stapled variant of MOTS-c designed to pre-organize residues 5–9 into a defined helical turn for improved AMPK alpha-2 engagement. Despite sound chemical rationale, the structural prediction returned a global pLDDT of 0.60 — statistically indistinguishable from the native baseline of ~0.62 across prior folds — and a very low ipTM of 0.23, indicating Boltz-2 could not confidently model the peptide docked against the AMPK alpha-2 interface. The staple did not deliver the predicted local helical stabilization, and the fold is discarded as biologically uninformative in silico. The negative result narrows the design space: hydrocarbon constraint at positions 5/9 does not rescue the structural ambiguity that has persisted across all five MOTS-c folds in this lab.","detailed_analysis":"MOTS-c is a 16-amino acid mitochondrial-derived peptide (MDP) encoded within the 12S rRNA of the mitochondrial genome, first characterized by Lee et al. (2015) as a regulator of insulin sensitivity and metabolic homeostasis through inhibition of the folate cycle and de novo purine biosynthesis. The resulting AICAR accumulation activates AMPK — a validated master energy sensor — making MOTS-c a compelling longevity target. Despite strong biological interest, MOTS-c presents a persistent structural challenge in this lab: it is short (16 residues), intrinsically disordered, and has returned pLDDT values clustering tightly around 0.62–0.63 across every modification tested (Folds #5, #19, #25), suggesting the sequence itself resists confident fold prediction regardless of point substitutions or lipidation.\n\nFold #30 pursued a qualitatively different strategy: all-hydrocarbon i,i+4 stapling between positions 5 and 9, replacing Met-5 and Tyr-9 with (S)-2-(4'-pentenyl)alanine (S5) non-natural residues followed by ruthenium-catalyzed ring-closing metathesis. The design logic was rigorous. Hydrocarbon stapling at i,i+4 spacing is the canonical approach to enforce a single helical turn while leaving side chains at non-stapled positions free for receptor engagement. Positioning the staple on the solvent-exposed face — away from the proposed cationic C-terminal patch (R12/K13/R16) and aromatic residues Trp-3 and Phe-10 — was intended to preserve the AMPK-engaging surface characterized computationally in Fold #19. Replacing Met-5 also addressed the oxidation liability flagged in the Nle substitution rationale of Fold #5, making this a two-for-one design.\n\nThe structural prediction, however, did not support the hypothesis. Global pLDDT returned at 0.60 — marginally lower than the native baseline and within noise for a single-run prediction — and critically, the ipTM of 0.23 indicates Boltz-2 could not produce a confident model of the stapled peptide engaging the AMPK alpha-2 interface. This inter-chain confidence score is the most diagnostic metric for a docking-dependent hypothesis: values below ~0.40 typically indicate the interface geometry is not predicted with meaningful confidence. The Boltz-2 affinity module returned no values, and no Chai-1 agreement run was available, leaving the prediction unsupported by any orthogonal structural scorer.\n\nThe literature context from the LITERATURE agent deepens the interpretive challenge. The dominant mechanistic model for MOTS-c's AMPK activation is indirect — through AICAR accumulation — rather than direct AMPK binding. No experimental structure of MOTS-c in any conformation has been published; no SAR data exists at residue resolution; and the specific hypothesis that the C-terminal cationic patch directly contacts the AMPK alpha-2 regulatory interface originates from Fold #19's computational modeling, not from published biochemistry. The literature agent also identifies a meaningful concern the researcher acknowledged but did not fully resolve: Tyr-9 carries a hydroxyl and aromatic side chain that may contribute to binding in the native peptide, and its wholesale replacement with a pentenyl-alanine stapling residue eliminates both features simultaneously.\n\nAcross the five MOTS-c folds in this lab (#5, #19, #22 Humanin for comparison, #25, #30), no modification has broken through the 0.63 pLDDT ceiling. The pattern is now statistically meaningful rather than incidental: point substitutions (K13R, Nle-1), lipidation (myristoylation), and now covalent constraint (hydrocarbon staple) all return structurally similar, low-confidence predictions. This is consistent with the literature agent's conclusion that MOTS-c may function through multiple conformational modes across cytoplasm, nucleus, and membrane compartments — a biologically flexible peptide for which conformational constraint may be philosophically misaligned with the actual mechanism.\n\nHeuristic sequence-based estimates from the structural run show an aggregation propensity of 0.054 (low — favorable), a stability score of 0.461 (moderate), and a half-life estimate in the moderate range (~30 min–2 hrs). These are not elevated relative to the native peptide and do not compensate for the structural prediction failure. BBB penetration probability of 0.13 is low, consistent with MOTS-c's primary role in peripheral metabolic tissues.\n\nThe honest assessment is that this fold delivers a meaningful negative result: covalent helical pre-organization via hydrocarbon stapling at i,i+4 (Glu-5/Lys-9 face) does not rescue MOTS-c's structural ambiguity in silico. Whether this reflects a genuine absence of stable helical propensity in the native sequence, a limitation of Boltz-2 in handling non-natural stapling residues (S5), or both, cannot be resolved from a single prediction run. The negative result should redirect future efforts away from conformation-locking strategies and toward functional surface engineering, indirect pathway modulation, or alternative delivery approaches building on Fold #25's lipidation precedent.","executive_summary":"MOTS-c i,i+4 hydrocarbon staple (Met-5/Tyr-9 → S5): pLDDT 0.60, ipTM 0.23 — no improvement over the native baseline and no confident AMPK interface docking. Four consecutive MOTS-c folds now cluster near the same structural ceiling, pointing toward a fundamental prediction limit rather than a solvable design problem.","tweet_draft":"DISTILLATION №30 — discarded.\nMOTS-c, i,i+4 hydrocarbon staple (Met-5/Tyr-9 → S5).\npLDDT 0.60 (native baseline ~0.62). ipTM 0.23.\nHelical pre-organization not detected. AMPK docking unresolved.\n4th MOTS-c fold. Same ceiling. The disorder may be the feature.\nIn silico only. alembic.bio","research_brief_markdown":"# DISTILLATION №30 — DISCARDED\n## MOTS-c i,i+4 Stapled Helix (Glu-5/Lys-9)\n\n**Verdict:** DISCARDED — structural prediction uninformative\n**pLDDT:** 0.60 | **ipTM:** 0.23 | **pTM:** 0.57\n\n---\n\n## Mechanism of Action (Background)\n\nMOTS-c is a 16-amino acid mitochondrial-derived peptide (MDP) encoded within the 12S rRNA of the mitochondrial genome. Its primary established mechanism (Lee et al., 2015, PMID:25738459) is inhibition of the folate cycle and de novo purine biosynthesis, leading to accumulation of AICAR (5-aminoimidazole-4-carboxamide ribonucleotide). AICAR is a well-validated indirect activator of AMPK — the master cellular energy sensor — which drives glucose uptake, fatty acid oxidation, and metabolic homeostasis. The AICAR–AMPK axis is the consensus signaling route in the literature (PMID:36677050, PMID:36761202), placing MOTS-c's AMPK engagement primarily in the indirect category.\n\nBeyond metabolic regulation, MOTS-c has demonstrated activity in gestational diabetes, bone metabolism, pulmonary fibrosis, ovarian cancer (where it competes for protein-protein interaction surfaces with LARS1/USP7), and cardiovascular conditions. Nuclear translocation under stress conditions has been documented, implicating multiple conformational modes and binding partners across cellular compartments. No experimental structure of MOTS-c — free or bound — has been published, and no residue-level SAR data exists.\n\n---\n\n## Modification Hypothesis (What We Tested)\n\nFold #30 introduced an all-hydrocarbon i,i+4 staple between positions 5 and 9 of MOTS-c, replacing Met-5 and Tyr-9 with (S)-2-(4'-pentenyl)alanine (S5) non-natural residues followed by ruthenium-catalyzed ring-closing metathesis:\n\n```\nNative:  M  R  W  Q  E  M  G  Y  I  F  Y  P  R  K  L  R\n         1  2  3  4  5  6  7  8  9  10 11 12 13 14 15 16\nStapled: M  R  W  Q  E [S5] G  Y  I [S5] F  Y  P  R  K  L  R\n```\n\nThe design rationale was threefold:\n1. **Conformational pre-organization**: Enforce a single helical turn spanning residues 5–9 to reduce the entropic cost of AMPK engagement, exploiting the well-established principle that intrinsically disordered peptides bind targets with lower affinity due to the conformational entropy penalty.\n2. **Oxidation resistance at Met-5**: Replacing oxidation-prone Met-5 with a non-oxidizable S5 stapling residue addressed the same stability liability flagged in the Nle substitution of **Fold #5** — a two-for-one modification.\n3. **Preservation of the binding surface**: The staple was positioned on the solvent-exposed face (Met-5/Tyr-9), leaving the cationic C-terminal patch (R12/K13/R16, the AMPK-engaging surface explored computationally in **Fold #19**) and aromatic residues Trp-3/Phe-10 unperturbed.\n\nThis was the first application of hydrocarbon stapling to MOTS-c or any MDP in the literature, and the first stapled peptide in this lab's longevity series.\n\n---\n\n## Why the Prediction Was Uninformative\n\n**Global structural confidence did not improve.** pLDDT returned at 0.60 — marginally *lower* than the native MOTS-c baseline of ~0.62 observed across Folds #5, #19, and #25. For a single-run prediction, this difference is within noise. The predicted improvement to >0.65–0.70 in the stapled region did not materialize.\n\n**Inter-chain docking confidence collapsed.** The ipTM of 0.23 is the most diagnostic metric here. For a peptide–protein complex prediction, ipTM values below ~0.40 indicate that the model cannot confidently place the peptide at the target interface. Boltz-2 essentially could not predict a meaningful bound geometry for the stapled MOTS-c against the AMPK alpha-2 catalytic subunit. The affinity module returned no values, consistent with this failure mode.\n\n**The predicted helical turn was not observed.** Despite the staple spanning residues 5–9, the structural output did not show a clearly defined α-helical segment with elevated local pLDDT in that region. The C-terminal cationic patch (R12/K13/R16) and aromatic residues appeared structurally unperturbed — consistent with design intent — but absence of disruption at the retained surface is not evidence of functional improvement.\n\n**Possible technical contributors to the failure:**\n- Boltz-2 and similar structure predictors are trained primarily on natural amino acids. The S5 non-natural stapling residue (pentenyl side chain with a covalent hydrocarbon bridge) is chemically exotic and may not be modeled accurately, potentially explaining why the expected local helical stabilization was not predicted.\n- The staple is represented as a sequence-level modification, but the covalent constraint geometry requires accurate modeling of the metathesis-derived bridge — a feature that current AlphaFold-family tools handle imperfectly at best.\n- Single-run prediction without ensemble or multiple seeds cannot distinguish whether the low confidence reflects genuine disorder or prediction uncertainty from the non-natural residue representation.\n\n---\n\n## What This Tells Us (Negative Results Are Data)\n\n**The structural ambiguity of MOTS-c is not resolved by i,i+4 hydrocarbon stapling at positions 5/9 — at least not in a way current predictors can detect.** Across five MOTS-c folds in this lab:\n\n| Fold | Modification | pLDDT | Verdict |\n|------|-------------|-------|--------|\n| #5 | Met-1 → Nle | 0.62 | PROMISING |\n| #19 | Lys-13 → Arg | 0.63 | PROMISING |\n| #25 | N-terminal myristoylation | 0.63 | PROMISING |\n| #30 | i,i+4 hydrocarbon staple (5/9) | 0.60 | DISCARDED |\n\nThe 0.62–0.63 pLDDT cluster is now a reproducible feature of MOTS-c predictions regardless of modification class (point substitution, lipidation, covalent constraint). This consistent ceiling suggests either: (a) the sequence intrinsically lacks helical propensity that current tools can amplify; (b) the AMPK alpha-2 complex geometry is not well-captured for this peptide class; or (c) both.\n\nThe negative result also raises a literature-grounded concern: **if MOTS-c's primary AMPK mechanism is indirect** (via AICAR accumulation through folate/purine pathway inhibition), then conformational optimization for direct AMPK binding may be chasing the wrong target entirely. Locking MOTS-c into a single helical conformation could actively impair its multi-compartment function (cytoplasmic metabolism, nuclear translocation, membrane interaction), consistent with the literature agent's assessment that conformational flexibility may be required for MOTS-c's broad activity profile.\n\nThe Tyr-9 → S5 substitution introduces a specific concern that deserves explicit note: Tyr-9 is an aromatic residue with a hydroxyl group that could contribute to hydrogen bonding at a binding interface. Replacing it with a hydrophobic pentenyl chain eliminates both features, a modification that could reduce biological activity independent of the helical constraint effect.\n\n---\n\n## Alternative Hypotheses to Test\n\nGiven the consistent structural prediction ceiling for MOTS-c and the indirect-mechanism concerns from the literature:\n\n1. **Shorter, truncated analogs**: Rather than constraining the full 16-mer, identify a minimal active fragment (e.g., the C-terminal cationic tail, residues 12–16, as a standalone peptide) and test whether a shorter sequence achieves better structural confidence. The conformational entropy problem scales with sequence length.\n\n2. **Extend the lipidation strategy from Fold #25**: Myristoylation returned PROMISING at pLDDT 0.63 with a delivery-focused rationale. Testing a palmitoyl (C16) or stearoyl (C18) variant, or adding a PEG spacer between the fatty acid and Met-1, may improve membrane engagement metrics without disrupting the functional sequence. This parallels the palmitoylation work in Fold #27 on FOXO4-DRI.\n\n3. **Lactam stapling as an alternative constraint chemistry**: The TB-500 lactam cyclization fold in the recent lab history demonstrated that ring-forming strategies can produce interpretable outputs. A Glu-5/Lys-9 or Asp-5/Lys-9 lactam bridge — avoiding the non-natural amino acid representation problem that may have confounded this fold — could be attempted as a chemically distinct conformational constraint on the same helix-spanning positions.\n\n4. **C-terminal modification building on Fold #19**: K13R delivered a modest but consistent PROMISING signal. A double substitution (K13R + R12 methylation or R16 modification) targeting the cationic patch more aggressively, without touching the central region, avoids the conformational disruption risk entirely.\n\n5. **Abandon direct AMPK targeting; explore AICAR pathway mimicry**: If MOTS-c acts primarily via AICAR, designing an analog optimized for folate cycle enzyme inhibition (direct binding to ATIC or MTHFD enzymes) rather than AMPK engagement may be mechanistically better aligned. This would require target switching and a new structural hypothesis.","structural_caption":"The stapled MOTS-c variant adopts a partially structured conformation but does not show the predicted clear helical turn at residues 5–9 with elevated local confidence. The very low ipTM (0.23) indicates Boltz-2 could not confidently dock the peptide against the AMPK alpha-2 interface. Overall pLDDT (0.60) is statistically indistinguishable from the reported native baseline (~0.62), so the staple did not measurably improve global fold confidence in this single run. The C-terminal cationic patch (R12/K13/R16) and aromatic Trp-3/Phe-10 appear unperturbed, consistent with the design intent, but the predicted bioactive engagement is not supported.","key_findings_summary":"MOTS-c is a 16-amino acid mitochondrial-derived peptide (MDP) encoded within the 12S rRNA region of the mitochondrial genome, first characterized by Lee et al. (2015, PMID:25738459) as a regulator of insulin sensitivity and metabolic homeostasis. The foundational mechanistic work established that MOTS-c's primary cellular action involves inhibition of the folate cycle and de novo purine biosynthesis, leading to accumulation of AICAR (5-aminoimidazole-4-carboxamide ribonucleotide), which in turn activates AMPK. This AICAR-AMPK axis is consistently cited across the review literature (PMID:36677050, PMID:36761202) as the dominant signaling mechanism, with skeletal muscle identified as the primary target organ. Critically, none of the available papers provide atomistic or structural detail about which residues of MOTS-c directly contact AMPK subunits, meaning the specific hypothesis regarding the AMPK alpha-2 regulatory interface and the cationic C-terminal patch (R12-K13-R16) engaging that interface is not directly validated or refuted by published structural biology.\n\nThe biological breadth of MOTS-c activity is well-documented across multiple disease contexts. Beyond metabolic regulation, MOTS-c has demonstrated effects in gestational diabetes (PMID:34798268), bone metabolism (PMID:37200834), pulmonary fibrosis (PMID:37307934), ovarian cancer (PMID:39321430), and cardiovascular conditions including atrial fibrillation (DOI:10.20944/preprints202604.0328.v1). A particularly relevant mechanistic finding from the cancer paper (PMID:39321430) is that MOTS-c physically interacts with protein partners (LARS1) in a manner competitive with other binding proteins, suggesting the peptide has defined protein-protein interaction surfaces—consistent with the hypothesis that specific residues mediate AMPK engagement. However, no published study has mapped the MOTS-c–AMPK binding interface at residue resolution, and no crystal structure or NMR structure of MOTS-c in complex with any target has been reported in the available literature.\n\nRegarding the structural biology rationale for stapling, the literature universally notes that MOTS-c is a short, 16-residue peptide, but no published study has experimentally determined its solution structure or assessed its helical content by circular dichroism (CD) or NMR. The review papers describe MOTS-c as a signaling peptide without discussing secondary structure. The claim of a largely disordered native conformation (pLDDT ~0.62) is consistent with AlphaFold2 predictions for short bioactive peptides but is not corroborated by experimental structural data in the available corpus. The broader rationale for hydrocarbon stapling—constraining intrinsically disordered peptides into bioactive helical conformations to improve target affinity and proteolytic stability—is well-established in the stapled peptide field generally, but this specific application to MOTS-c has no precedent in the literature provided.\n\nThe preprint literature (Cheema et al., 2025; Liao et al., 2026) extends MOTS-c's therapeutic relevance to ME/CFS and atrial fibrillation, consistently citing AMPK and NRF2 activation as core mechanisms. However, these preprints are preliminary, lack peer review in their current form, and do not address structural or medicinal chemistry aspects. No human clinical trials with MOTS-c have been reported, and the safety/efficacy data in humans is explicitly described as lacking (DOI:10.20944/preprints202507.0058.v1). This limits the translational context for any stapled analog but does not undermine the in vitro or preclinical target engagement rationale."},"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 firmly establishes that MOTS-c activates AMPK through the AICAR pathway (via folate cycle/purine biosynthesis inhibition) and that this mechanism underlies its beneficial metabolic, anti-inflammatory, and cytoprotective effects across multiple disease models. There is strong, peer-reviewed consensus that MOTS-c is biologically active and therapeutically relevant. However, the literature does not address the structural basis of MOTS-c's interaction with AMPK or any other protein target at residue resolution. No published experimental structure of MOTS-c (free or bound) exists in the available corpus. The question of whether MOTS-c acts directly on AMPK as a binding partner versus indirectly through AICAR accumulation is not conclusively resolved—most mechanistic papers favor the indirect AICAR-mediated route. The specific hypothesis that the C-terminal cationic patch (R12-K13-R16) directly contacts the AMPK alpha-2 subunit regulatory interface is not supported or refuted by published data and appears to derive from computational modeling (Fold #19 reference in the hypothesis). Hydrocarbon stapling of MOTS-c has no literature precedent whatsoever.","knowledge_gaps":"Critical knowledge gaps include: (1) No experimental solution or crystal structure of MOTS-c in any conformation has been published, making the claim of a 'largely disordered native peptide' computationally inferred rather than experimentally validated. (2) The direct binding interface between MOTS-c and AMPK alpha-2 has never been characterized—it remains unclear whether MOTS-c binds AMPK directly at all, or whether its effects are entirely indirect through AICAR. (3) No structure-activity relationship (SAR) studies on MOTS-c have been published, meaning the contribution of individual residues (including Met-5, Tyr-9, Trp-3, Phe-10, R12, K13, R16) to biological activity is unknown. (4) The proteolytic stability of native MOTS-c in plasma and cellular environments has not been systematically characterized in the available literature. (5) No stapled peptide analog of MOTS-c or any other MDP has been reported. (6) Whether pre-organization into a helical conformation enhances rather than disrupts MOTS-c's biological activity (given it may require conformational flexibility for multiple interaction modes across cytoplasm, nucleus, and membrane environments) is entirely unknown.","supporting_evidence":"Several lines of indirect evidence support the hypothesis: (1) The AICAR-AMPK mechanism (PMID:25738459) implies a functional interaction between MOTS-c-induced metabolites and AMPK, providing a validated target pathway. (2) The demonstration that MOTS-c directly competes for protein binding interfaces (LARS1/USP7, PMID:39321430) establishes that MOTS-c has defined protein interaction surfaces capable of competitive binding, consistent with the idea that specific residues (the proposed C-terminal cationic patch) mediate AMPK engagement. (3) The poor clinical translation noted across multiple reviews (PMID:36761202, preprint DOI:10.20944/preprints202507.0058.v2) highlights stability and delivery limitations of native MOTS-c that stapling could address. (4) The nuclear translocation behavior (PMID:31378979) demonstrates MOTS-c can adopt conformations that engage diverse intracellular partners, supporting the concept that stabilizing one conformation (the proposed helical state) could selectively enhance one mode of engagement. (5) The placement of the staple on the solvent-exposed face (Met-5/Tyr-9) away from the proposed cationic engagement surface is a sound chemical logic consistent with established stapled peptide design principles, even though MOTS-c-specific validation is absent.","challenging_evidence":"Several factors complicate or challenge the hypothesis: (1) The dominant mechanistic model in the literature is that MOTS-c activates AMPK indirectly via AICAR accumulation (inhibition of folate cycle/purine biosynthesis), not through direct AMPK binding. If this indirect mechanism is correct, then pre-organizing a helical conformation to engage 'the AMPK alpha-2 regulatory interface' may be irrelevant to the actual biological mechanism. (2) MOTS-c's nuclear translocation role (PMID:31378979) and its demonstrated interaction with LARS1 (PMID:39321430) suggest the peptide may function through multiple mechanisms and partners, meaning a conformationally constrained analog optimized for one interface could lose activity at others. (3) Tyr-9 is an aromatic residue that in natural peptides frequently participates in binding interactions; replacing it with (S)-2-(4'-pentenyl)alanine removes the hydroxyl and the aromatic side chain, which could disrupt any binding contributions from this position—the hypothesis notes Phe-10 as an aromatic anchor but does not address potential loss of Tyr-9's functional contribution. (4) Similarly, Met-5 replacement removes a sulfur-containing side chain that may contribute to hydrophobic packing in the native bioactive conformation. (5) No CD, NMR, or crystallographic evidence of any helical tendency in native MOTS-c is available, making the premise that there is a pre-existing helical 'bioactive conformation' to stabilize speculative. (6) The atrial fibrillation preprint (DOI:10.20944/preprints202604.0328.v1) lacks a proper abstract and cannot be assessed for methodological rigor. (7) All human-relevant evidence remains preclinical, and the biological relevance of AMPK alpha-2 as opposed to alpha-1 isoform selectivity for MOTS-c is not discussed anywhere in the available literature."},"caveats":["in silico prediction only — requires wet lab validation","single-run prediction (not ensembled) — confidence metrics should be interpreted with caution","predicted properties may not reflect real-world biological behavior","this is research, not medical advice","Boltz-2 and related structure predictors are trained primarily on natural amino acids; the (S)-2-(4'-pentenyl)alanine (S5) stapling residue and covalent hydrocarbon bridge geometry may be modeled inaccurately, potentially explaining the absence of predicted helical stabilization","the covalent RCM-derived staple constraint cannot be faithfully represented as a simple sequence substitution — the geometric rigidity of the bridge is likely undermodeled","no Chai-1 agreement run was available for orthogonal structural validation; ipTM of 0.23 is based on Boltz-2 alone","heuristic property estimates (aggregation propensity, stability score, half-life, BBB penetration) are sequence-based approximations only and do not account for the non-natural stapling residues or the covalent bridge","the dominant MOTS-c mechanism in the literature is indirect AMPK activation via AICAR — whether direct AMPK alpha-2 binding occurs at all remains unresolved experimentally","no SAR data for MOTS-c exists in the published literature; the functional consequences of Met-5 and Tyr-9 substitution are entirely unknown"],"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 paper establishing MOTS-c's mechanism of action via AICAR-AMPK activation in skeletal muscle; directly defines the target pathway central to our hypothesis."},{"pmid_or_doi":"36677050","title":"MOTS-c Functionally Prevents Metabolic Disorders","year":2023,"relevance":"Comprehensive review summarizing MOTS-c signaling through AICAR-AMPK pathways and downstream gene targets (GLUT4, STAT3, IL-10), providing context for the AMPK alpha-2 targeting rationale."},{"pmid_or_doi":"36761202","title":"MOTS-c: A promising mitochondrial-derived peptide for therapeutic exploitation","year":2023,"relevance":"Reviews MOTS-c therapeutic applications and notes absence of effective clinical delivery methods, supporting the motivation for a stabilized stapled analog."},{"pmid_or_doi":"31378979","title":"MOTS-c: A Mitochondrial-Encoded Regulator of the Nucleus","year":2019,"relevance":"Establishes that MOTS-c translocates to the nucleus under metabolic stress and regulates gene expression, indicating the peptide must adopt conformations capable of multiple protein interactions in different cellular compartments."},{"pmid_or_doi":"39321430","title":"Mitochondrial-Derived Peptide MOTS-c Suppresses Ovarian Cancer Progression by Attenuating USP7-Mediated LARS1 Deubiquitination","year":2024,"relevance":"Demonstrates that MOTS-c engages defined protein-protein interaction surfaces (competing with USP7 for LARS1 binding), providing indirect evidence that specific MOTS-c residues mediate target recognition—relevant to the hypothesis that the C-terminal cationic patch engages AMPK alpha-2."},{"pmid_or_doi":"34798268","title":"The mitochondrial-derived peptide MOTS-c relieves hyperglycemia and insulin resistance in gestational diabetes mellitus","year":2022,"relevance":"In vivo demonstration of MOTS-c activating insulin sensitivity via skeletal muscle AMPK, confirming biological relevance of the AMPK target in a metabolic disease context."},{"pmid_or_doi":"37200834","title":"Role of MOTS-c in the regulation of bone metabolism","year":2023,"relevance":"Documents pleiotropic MOTS-c activity beyond metabolic regulation, noting exercise upregulates MOTS-c expression; relevant for understanding the peptide's natural pharmacology and the value of a stabilized analog."},{"pmid_or_doi":"37307934","title":"MOTS-c: A potential anti-pulmonary fibrosis factor derived by mitochondria","year":2023,"relevance":"Extends MOTS-c activity to fibrotic disease via AMPK and cellular homeostasis pathways, reinforcing the breadth of AMPK-dependent MOTS-c biology that a stapled analog could leverage."},{"pmid_or_doi":"10.20944/preprints202507.0058.v2","title":"Redefining Mitochondrial Therapy for ME/CFS: The Case for MOTS-c","year":2025,"relevance":"Preprint explicitly acknowledging lack of human safety/efficacy data for MOTS-c and noting AMPK/NRF2 as key targets; contextualizes the unmet need for improved MOTS-c analogs."},{"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 broadening MOTS-c's cardiovascular relevance; limited value for structural hypothesis but confirms ongoing interest in MOTS-c as a therapeutic peptide across disease areas."}]},"onchain":{"hash":"5m5hK3hhVyMEQFNNuQb4cNkCffRmz8xTvHLV86DnbbcxKTuHwhNynhta3imtUnP3snJS2MNc8R8kbdYGwQHtb4Qj","signature":"5m5hK3hhVyMEQFNNuQb4cNkCffRmz8xTvHLV86DnbbcxKTuHwhNynhta3imtUnP3snJS2MNc8R8kbdYGwQHtb4Qj","data_hash":"d7348afbdac3b40dbe09eacf84b1e6b6f56ac26ccdb1c4d1ac81adb911df801d","logged_at":"2026-05-03T09:31:04.110880+00:00","explorer_url":"https://solscan.io/tx/5m5hK3hhVyMEQFNNuQb4cNkCffRmz8xTvHLV86DnbbcxKTuHwhNynhta3imtUnP3snJS2MNc8R8kbdYGwQHtb4Qj"},"ipfs_hash":null,"created_at":"2026-05-03T08:56:14.601010+00:00","updated_at":"2026-05-03T09:31:04.117270+00:00"}