MOTS-c: A Novel Peptide Encoded by a Short Mitochondrial Open Reading Frame Regulates Metabolic Homeostasis
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE65068 | GEO | 2015/03/07
SECONDARY ACCESSION(S): PRJNA272824
REPOSITORIES: GEO
Similar Datasets
Project description:Mitochondria are known to be functional organelles, but their role as a signaling unit is increasingly being appreciated. The recent 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 that yield bioactive peptides. Here we report the identification of a sORF within the mitochondrial 12S rRNA encoding a 16-amino-acid peptide named MOTS-c (mitochondrial open-reading-frame of the twelve S rRNA -c) that regulates insulin sensitivity and metabolic homeostasis. MOTS-c is detected in various tissues and in circulation in an age-dependent manner. 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, causing a significant accumulation of AICAR levels concomitantly with 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 be more actively engaged in regulating metabolic homeostasis than previously recognized, through the production of peptides encoded within its genome that act at the cellular and organismal level. Human embryonic kidney cells (HEK293 cell line) were cultured in 10-cm dishes in 7 mL of phenol-free DMEM supplemented with 10% FBS and incubated with water (controls) or the 16-amino-acid peptide mitochondrial open-reading-frame of the twelve S rRNA-c (MOTS-c, 10 uM) for 4 or 72 hours prior to RNA extraction.
2015-03-07 | E-GEOD-65068 | biostudies-arrayexpress
Project description:Mitochondria are important organelles controlling productivity and metabolism in cells. Recent studies have found that there are short open reading frames on mitochondrial genomes that has not been discovered before, which could encode short peptides, and we called them mitochondrial-derived peptides (MDPs), including MOTS-c encoded by 12S-rRNA, Humanin(HN) and SHLP1-6 encoded by 16S-rRNA. As a new class of circulating signaling molecules, these mitochondrial-derived peptides play an important function in certain human life activities or the occurrence of diseases. In order to study the potential unknown function of MDP and the molecular mechanism behind it, overexpressing MDPs were used as bait protein to conduct systematic immunoprecipitation experiment.
2022-01-12 | PXD030898 | iProX
Project description:MOTS-c: A Novel Peptide Encoded by a Short Mitochondrial Open Reading Frame Regulates Metabolic Homeostasis
| PRJNA272824 | ENA
Project description:Upon initiation at an AUG start codon, the ribosome must maintain the correct reading frame for hundreds of codons in order to produce functional proteins. Although some sequence elements are able to trigger programmed ribosomal frameshifting (PRF), very little is known how the ribosome normally prevents spontaneous frameshift errors. Using high resolution ribosome profiling data sets, we discovered that the translating ribosome uses the 3’ end of 18S rRNA to scan the AUG-like codons after the decoding process. The internal mRNA:rRNA interaction not only contributes to predominant translational pausing, but also provides a post-decoding mechanism to safeguard the ribosome in the correct reading frame. Partially eliminating the AUG-like “sticky” codons in the reporter message leads to increased +1 frameshift errors. Remarkably, mutating the highly conserved CAU triplet of 18S rRNA globally changes codon “stickiness”. Further supporting the role of “sticky” sequences in reading frame maintenance, the codon composition of open reading frames is highly optimized across eukaryotic genomes by minimizing the appearance of AUG-like codons in the frame 2. These results suggest an important layer of information embedded within the protein coding sequences that instructs the ribosome to ensure reading frame fidelity during translation.
2016-04-12 | GSE80156 | GEO
Project description:It has been reported that human mesenchymal stem cells (MSCs) can transfer mitochondria to the cells with severely compromised mitochondrial function. We tested whether MSCs transfer mitochondria to the cells under several different conditions of mitochondrial dysfunction, including human pathogenic mitochondrial DNA (mtDNA) mutations. Using biochemical selection methods, we found that exponentially growing cells in restrictive media (uridine and bromodeoxyuridine [BrdU]+) after coculture of MSCs (uridine-independent and BrdU-sensitive) and 143B-derived cells with severe mitochondrial dysfunction induced by either long-term ethidium bromide treatment or short-term rhodamine 6G (R6G) treatment (uridine-dependent but BrdU-resistant). The exponentially growing cells had nuclear DNA fingerprint patterns identical to 143B, and a sequence of mtDNA identical to the MSCs. Since R6G causes rapid and irreversible damage to mitochondria without the removal of mtDNA, the mitochondrial function appears to be restored through a direct transfer of mitochondria rather than mtDNA alone. Conditioned media, which were prepared by treating mtDNA-less 143B 0 cells under uridine-free condition, induced increased chemotaxis in MSC, which was also supported by transcriptome analysis. A chemotaxis inhibitory agent blocked mitochondrial transfer phenomenon in the above condition. However, we could not find any evidence of mitochondrial transfer to the cells harboring human pathogenic mtDNA mutations (A3243G mutation or 4,977 bp deletion). Thus, the mitochondrial transfer is limited to the condition of a near total absence of mitochondrial function. Elucidation of the mechanism of mitochondrial transfer will help us create a potential “cell therapy-based mitochondrial restoration or mitochondrial gene therapy” for human diseases caused by mitochondrial dysfunction. time series
2011-11-22 | E-GEOD-33831 | biostudies-arrayexpress
Project description:<p><strong>INTRODUCTION:</strong> The mitochondrial-derived peptides (MDPs) are a novel group of natural occurring peptides that have important signaling functions and biological activity. Both humanin and small-humanin-like peptide 2 (SHLP2) have been reported to act as insulin sensitizers and modulate metabolism.</p><p><strong>OBJECTIVES:</strong> By using a metabolomic approach, this study explores how the plasma metabolite profile is regulated in response to humanin and SHLP2 treatment in a diet-induced obesity (DIO) mouse model. The results also shed light on the potential mechanism underlying MDPs insulin sensitization effects.</p><p><strong>METHODS </strong>Plasma samples were obtained from DIO mice subjected to vehicle (water) treatment, or peptide treatment with either humanin analog S14G (HNG) or SHLP2 (n = 6 per group). Vehicle or peptides were given as intraperitoneal (IP) injections twice a day at dose of 2.5mg/kg/injection for 3 days. Metabolites in plasma samples were comprehensively identified and quantified using UPLC-MS/MS.</p><p><strong>RESULTS:</strong> HNG and SHLP2 administration significantly altered the concentrations of amino acid and lipid metabolites in plasma. Among all the metabolic pathways, the glutathione and sphingolipid metabolism responded most strongly to the peptide treatment.</p><p><strong>CONCLUSIONS:</strong> The present study indicates that humanin and SHLP2 can lower several markers associated with age-related metabolic disorders. With the previous understanding of the effects of humanin and SHLP2 on cardiovascular function, insulin sensitization, and anti-inflammation, this metabolomic discovery provides a more comprehensive molecular explanation of the mechanism of action for humanin and SHLP2 treatment.</p>
2019-06-21 | MTBLS159 | MetaboLights
Project description:The emergence of small open reading frame (sORF)-encoded peptides (SEPs) is rapidly expanding the known proteome at the lower end of the size distribution. Here, we show that the mitochondrial proteome is enriched for proteins smaller than 100 a.a. (defined as SEPs). Using a prediction and validation pipeline for small open-reading-frame (sORF)-encoded peptides (SEPs), we report the discovery of 16 endogenous nuclear encoded, mitochondrial-localized SEPs (mito-SEPs). Through functional prediction, proteomics, metabolomics and metabolic flux modeling, we demonstrate that BRAWNIN (BR), a 71 amino acid peptide encoded by the C12orf73 gene, is essential for respiratory chain complex III (CIII) assembly. In human cells, BR is induced by the energy-sensing AMPK pathway, and its depletion impairs mitochondrial ATP production. In vivo, BR is enriched in muscle tissues and its maternal zygotic deletion in zebrafish causes complete CIII loss, resulting in severe growth retardation, lactic acidosis and early death. Our findings demonstrate that BR is essential for oxidative phosphorylation across vertebrate species. We propose that mito-SEPs are an untapped resource for essential regulators of oxidative metabolism. The dataset included in this entry is for the Zebrafish and MEF BR knockouts.
2020-03-18 | PXD016718 | Pride
Project description:Somatic mitochondrial DNA (mtDNA) mutations contribute to the pathogenesis of age-related disorders, including myelodysplastic syndromes (MDS). The accumulation of mitochondria harboring mtDNA mutations in patients with these disorders suggests a failure of normal mitochondrial quality-control systems. The mtDNA-mutator mice acquire somatic mtDNA mutations via a targeted defect in the proofreading function of the mtDNA polymerase, PolgA, and develop macrocyticanemia similar to that of patients with MDS. We observed an unexpected defect in clearance of dysfunctional mitochondria at specific stages during erythroid maturation in hematopoietic cells from aged mtDNA-mutator mice. Mechanistically, aberrant activation of mechanistic target of rapamycin signaling and phosphorylation of uncoordinated 51-like kinase (ULK) 1 in mtDNA-mutator mice resulted in proteasome mediated degradation of ULK1 and inhibition of autophagy in erythroid cells. To directly evaluate the consequence of inhibiting autophagy on mitochondrial function in erythroid cells harboring mtDNA mutations in vivo, we deleted Atg7 from erythroid progenitors of wildtype and mtDNA-mutator mice. Genetic disruption of autophagy did not cause anemia in wild-type mice but accelerated the decline in mitochondrial respiration and development of macrocytic anemia in mtDNA-mutator mice. These findings highlight a pathological feedback loop that explains how dysfunctional mitochondria can escape autophagy-mediated degradation and propagate in cells predisposed to somatic mtDNA mutations, leading to disease. We used microarrays to identify expression profiles and pathways that are differentially activated or suppressed in Ter119+ bone marrow cells isolated from phlebotomized wildtype or Polg mutant mice
2015-04-21 | E-GEOD-57761 | biostudies-arrayexpress
Project description:Mitochondria generate signals of adaptation that regulate nuclear genes expression via retrograde signaling. But this phenomenon is complexified when qualitatively different mitochondria and mitochondrial DNA (mtDNA) coexist within cells. Although this cellular state of heteroplasmy leads to divergent phenotypes clinically, its consequences on cellular function and the cellular transcriptome are unknown. To interrogate this phenomenon, we generated somatic cell cybrids harboring increasing levels of a common mtDNA mutation (tRNALeu(UUR) 3243A>G) and mapped the resulting cellular phenotypes and transcriptional profiles across the complete range of heteroplasmy. Small increases in mutant mtDNAs caused relatively modest defect in mitochondrial oxidative capacity, but resulted in sharp transitions in mitochondrial ultrastructure and in the nuclear and mitochondrial transcriptomes, with the critical functional threshold corresponding to the induction of epigenetic regulatory systems. Principal component analysis underscores how each heteroplasmy level occupies a different "transcriptional space", with low levels heteroplasmy (20-30%) producing a dose-response linear progression in one direction, and mutationload of 50, 60 and 90% producing changes in the opposite direction. Hence, subtle changes in mitochondrial energetics can act through the epigenome to generate the phenotypes of the common “complex” diseases. Cells were generated by transferring the wildtype (3243A) and mutant (3243G) mtDNAs from a heteroplasmic 3243A>G patient’s lymphoblastoid cell line into 143B(TK-) mtDNA-deficient (ρo) cells and selected for transmitochondrial cybrids. Subsequent mtDNA depletion, reamplification, and cloning (Wiseman and Attardi, 1978) resulted in a series of stable cybrids harboring approximately 0, 20, 30, 50, 60, 90, and 100% 3243G mutant mtDNAs. Total RNA extracted from each cell line was then extracted, depleted of rRNA, and measured in sequenced in triplicates.
2014-09-02 | E-GEOD-56158 | biostudies-arrayexpress
Project description:Exercise is a fundamental component of human health that is associated with greater life expectancy and reduced risk of chronic diseases. While the beneficial effects of endurance exercise on human health are well established, the molecular mechanisms responsible for these observations remain unclear. Endurance exercise reduces the accumulation of mitochondrial DNA (mtDNA) mutations, alleviates multisystem pathology, and increases the lifespan of the mtDNA mutator mouse model of aging, in which the proof-reading capacity of mitochondrial polymerase gamma (POLG1) is deficient. Clearly, exercise recruited a POLG1-independent mtDNA repair pathway to induce these adaptations, a novel finding as POLG1 is canonically considered to be the sole mtDNA repair enzyme. Here we investigate the identity of this pathway, and show that endurance exercise prevents mitochondrial oxidative damage, attenuates telomere erosion, and mitigates cellular senescence and apoptosis in mtDNA mutator mice. Unexpectedly, we observe translocation of tumour suppressor protein p53 to mitochondria in response to endurance exercise that facilitates mtDNA mutation repair. Indeed, endurance exercise failed to prevent mtDNA mutations, induce mitochondrial biogenesis, preserve mitochondrial morphology, reverse sarcopenia, and mitigate premature mortality in mtDNA mutator mice with muscle-specific deletion of p53. Our data establish an exciting new role for p53 in exercise-mediated maintenance of the mtDNA genome, and presents mitochondrially-targeted p53 as a novel therapeutic modality for aging-associated diseases of mitochondrial etiology. Microarray analysis of gene expression from skeletal muscle (quadriceps femoris) from Mus musculus. N=23 samples per treatment were analysed for whole transcriptiome gene expression profile using NimbleGen Arrays. The treatment groups included wild-type C57Bl/6J mice as the control group, then two treatment groups which both contained homozygous knock-in mtDNA mutator mice (PolG; PolgAD257A/D257A). Once group of these heterozygous knock out mice received regular endurance exercise sessions while the other group remained sedentraty for 6 months. The control group specimens were wild-type litter mates to the transgenic knockout mice.
2015-12-11 | E-GEOD-75869 | biostudies-arrayexpress