Temporal landscape of mitochondrial proteostasis governed by the UPRmt
Ontology highlight
ABSTRACT:
INSTRUMENT(S): Orbitrap Fusion
ORGANISM(S): Homo Sapiens (human)
TISSUE(S): Epithelial Cell, Cell Culture
SUBMITTER: 
Joel Steele
LAB HEAD: Michael Lazarou
PROVIDER: PXD038403 | Pride | 2023-09-27
REPOSITORIES: Pride
Similar Datasets
Project description:The mitochondrial matrix is unique in that it must integrate folding and assembly of proteins derived from nuclear and mitochondrial genomes. In C. elegans, the mitochondrial unfolded protein response (UPRmt) senses matrix protein misfolding and induces a program of nuclear gene expression, including mitochondrial chaperonins, to promote mitochondrial proteostasis. While misfolded mitochondrial matrix-localized ornithine trans-carbamylase (OTC) induces chaperonin expression, our understanding of mammalian UPRmt is rudimentary, reflecting a lack of acute triggers for UPRmt activation. This limitation has prevented analysis of the cellular responses to matrix protein misfolding and the effects of UPRmt on mitochondrial translation to control protein folding loads. Here, we combine pharmacological inhibitors of matrix-localized HSP90/TRAP1 or LON protease, which promote chaperonin expression, with global transcriptional and proteomic analysis to reveal an extensive and acute response of human cells to UPRmt. This response involved widespread induction of nuclear genes, including matrix-localized proteins involved in folding, pre-RNA processing and translation. Functional studies revealed rapid but reversible translation inhibition in mitochondria occurring concurrently with defects in pre-RNA processing due to transcriptional repression and LON-dependent turnover of the mitochondrial pre-RNA processing nuclease MRPP3. This study reveals that acute mitochondrial protein folding stress activates both increased chaperone availability within the matrix and reduced matrix-localized protein synthesis through translational inhibition, and provides a framework for further dissection of mammalian UPRmt. triplicate experiment of 3 conditions (untreated, GTPP treatment, CDDO treatment)
2016-06-28 | E-GEOD-75247 | biostudies-arrayexpress
Project description:The mitochondrial matrix is unique in that it must integrate folding and assembly of proteins derived from nuclear and mitochondrial genomes. In C. elegans, the mitochondrial unfolded protein response (UPRmt) senses matrix protein misfolding and induces a program of nuclear gene expression, including mitochondrial chaperonins, to promote mitochondrial proteostasis. While misfolded mitochondrial matrix-localized ornithine trans-carbamylase (OTC) induces chaperonin expression, our understanding of mammalian UPRmt is rudimentary, reflecting a lack of acute triggers for UPRmt activation. This limitation has prevented analysis of the cellular responses to matrix protein misfolding and the effects of UPRmt on mitochondrial translation to control protein folding loads. Here, we combine pharmacological inhibitors of matrix-localized HSP90/TRAP1 or LON protease, which promote chaperonin expression, with global transcriptional and proteomic analysis to reveal an extensive and acute response of human cells to UPRmt. This response involved widespread induction of nuclear genes, including matrix-localized proteins involved in folding, pre-RNA processing and translation. Functional studies revealed rapid but reversible translation inhibition in mitochondria occurring concurrently with defects in pre-RNA processing due to transcriptional repression and LON-dependent turnover of the mitochondrial pre-RNA processing nuclease MRPP3. This study reveals that acute mitochondrial protein folding stress activates both increased chaperone availability within the matrix and reduced matrix-localized protein synthesis through translational inhibition, and provides a framework for further dissection of mammalian UPRmt. triplicate experiment of 2 conditions (untreated, GTPP treatment)
2016-06-28 | E-GEOD-75410 | biostudies-arrayexpress
Project description:The mitochondrial unfolded protein response (UPRmt) safeguards mitochondria from proteotoxic damage by activating a dedicated transcriptional response in the nucleus to restore proteostasis. How the mitochondrial protein misfolding information is signalled to the nucleus as part of the human UPRmt remains unclear. Here, we showed that UPRmt signalling is carried out by the co-occurrence of two individual signals – ROS production in mitochondria and accumulation of orphan mitochondrial proteins in the cytosol. Combining proteomics and genetic approaches, we identified that mitochondrial protein misfolding caused the release of ROS into the intermembrane space (IMS), which was essential for UPRmt signalling. ROS released from mitochondria oxidized the cytosolic HSP40 protein DNAJA1 to enhance recruitment of cytosolic HSP70 to orphan mitochondrial proteins that accumulated in parallel in the cytosol due to mitochondrial import defect. This recruitment leads to the release of HSF1 from HSP70 and its subsequent translocation to the nucleus to activate transcription of UPRmt related genes. Strikingly, we found that combining ROS and the accumulation of orphan mitochondrial proteins in the cytosol was sufficient and necessary to activate the UPRmt. Our findings reveal that monitoring of ROS and orphan mitochondrial proteins in cytosol allows an elegant surveillance to control the UPRmt via HSF1 activation in human cells. These observations reveal a novel link between mitochondrial and cytosolic proteostasis and provide molecular insight into UPRmt signalling.
2023-05-19 | PXD032011 | Pride
Project description:The mitochondrial unfolded protein response (UPRmt) safeguards mitochondria from proteotoxic damage by activating a dedicated transcriptional response in the nucleus to restore proteostasis. How the mitochondrial protein misfolding information is signalled to the nucleus as part of the human UPRmt remains unclear. Here, we showed that UPRmt signalling is carried out by the co-occurrence of two individual signals – ROS production in mitochondria and accumulation of orphan mitochondrial proteins in the cytosol. Combining proteomics and genetic approaches, we identified that mitochondrial protein misfolding caused the release of ROS into the intermembrane space (IMS), which was essential for UPRmt signalling. ROS released from mitochondria oxidized the cytosolic HSP40 protein DNAJA1 to enhance recruitment of cytosolic HSP70 to orphan mitochondrial proteins that accumulated in parallel in the cytosol due to mitochondrial import defect. This recruitment leads to the release of HSF1 from HSP70 and its subsequent translocation to the nucleus to activate transcription of UPRmt related genes. Strikingly, we found that combining ROS and the accumulation of orphan mitochondrial proteins in the cytosol was sufficient and necessary to activate the UPRmt. Our findings reveal that monitoring of ROS and orphan mitochondrial proteins in cytosol allows an elegant surveillance to control the UPRmt via HSF1 activation in human cells. These observations reveal a novel link between mitochondrial and cytosolic proteostasis and provide molecular insight into UPRmt signalling.
2023-05-19 | PXD031948 | Pride
Project description:Across eukaryotic species, mild mitochondrial stress can have beneficial effects on the lifespan of organisms. Mitochondrial dysfunction activates an unfolded protein response (UPRmt), a stress signaling mechanism designed to ensure mitochondrial homeostasis. Perturbation of mitochondria during larval development in C. elegans not only delays aging but also maintains UPRmt signaling, suggesting an epigenetic mechanism that modulates both longevity and mitochondrial proteostasis throughout life. Here we identify the conserved histone lysine demethylases jmjd-1.2/PHF8 and jmjd-3.1/JMJD3 as positive regulators of lifespan in response to mitochondrial dysfunction across species. Reduction-of-function of the demethylases potently suppresses longevity and UPRmt induction while gain-of-function is sufficient to extend lifespan in an UPRmt-dependent manner. A systems genetics approach in the BXD mouse reference population further indicated conserved roles of the mammalian orthologs in longevity and UPRmt signaling. These findings illustrate an evolutionary conserved epigenetic mechanism that determines the rate of aging downstream of mitochondrial perturbations.
2016-05-03 | GSE78990 | GEO
Project description:Mucus has an important protective function and forms a barrier that minimizes the bacterial contact with the colonic epithelium. It is organized as a complex network with several specific proteins of which most are still poorly understood. Abundant proteins in intestinal mucus, in addition to the mucin MUC2, are CLCA1 and FCGBP. FCGBP is expressed in all intestinal goblet cells and secreted into the mucus. It is comprised of repeated von Willebrand Factor D (vWD) domain assemblies, of which most have a GDPH amino acid sequence. This sequence can be autocatalytically cleaved, as previously found in MUC2 and MUC5AC. We show that all vWD with a GDPH sequence are cleaved, and that these cleavages occur early during biosynthesis in the endoplasmic reticulum. All cleaved fragments remained connected by a disulfide bond within each vWD domain. The cleavage can generate a C-terminal reactive Asp-anhydride that could react with other molecules, such as MUC2, but this was not observed. Quantitative analyses by mass spectrometry showed that, in chaotropic solutions, FCGBP was mainly soluble whereas MUC2 was insoluble, and most of the secreted FCGBP was not covalently bound to MUC2. As its name indicates, FCGBP has been suggested to bind IgG, something that was not possible to reproduce in vitro using purified proteins. The function of FCGBP is still unknown, but our results suggest that the Asp-anhydrides do not contribute to covalent crosslinking in the mucin framework nor does FCGBP incorporate IgG in mucus.
2021-06-09 | PXD025493 | Pride
Project description:Proteomics quantificatio nof the AgTU-induced protein aggregation by using soluble and insoluble buffers
2024-03-17 | PXD042467 | Pride
Project description:The spread of antibiotic resistance is a major challenge for treatment of Mycobacterium tuberculosis infection. In addition, efficacy of drugs is often limited by the restricted permeability of the mycomembrane. Frontline antibiotics inhibit mycomembrane biosynthesis leading to rapid cell death. Inspired by this mechanism we exploit β-lactones as putative mycolic acid mimics to block serine hydrolases involved in their biosynthesis. Among a collection of β-lactones we found one hit with potent anti-mycobacterial and bactericidal activity. Chemical proteomics using an alkynylated probe identified Pks13 and Ag85 serine hydrolases as major targets. Validation via enzyme assays and customized 13C metabolite profiling showed that both targets are functionally impaired by the β-lactone. Co-administration with front-line antibiotics enhanced the potency against M. tuberculosis by more than 100-fold demonstrating a therapeutic potential of targeting mycomembrane biosynthesis serine hydrolases.
2022-01-19 | PXD007699 | Pride
Project description:The mitochondrial matrix is unique in that it must integrate folding and assembly of proteins derived from nuclear and mitochondrial genomes. In C. elegans, the mitochondrial unfolded protein response (UPRmt) senses matrix protein misfolding and induces a program of nuclear gene expression, including mitochondrial chaperonins, to promote mitochondrial proteostasis. While misfolded mitochondrial matrix-localized ornithine trans-carbamylase (OTC) induces chaperonin expression, our understanding of mammalian UPRmt is rudimentary, reflecting a lack of acute triggers for UPRmt activation. This limitation has prevented analysis of the cellular responses to matrix protein misfolding and the effects of UPRmt on mitochondrial translation to control protein folding loads. Here, we combine pharmacological inhibitors of matrix-localized HSP90/TRAP1 or LON protease, which promote chaperonin expression, with global transcriptional and proteomic analysis to reveal an extensive and acute response of human cells to UPRmt. This response involved widespread induction of nuclear genes, including matrix-localized proteins involved in folding, pre-RNA processing and translation. Functional studies revealed rapid but reversible translation inhibition in mitochondria occurring concurrently with defects in pre-RNA processing due to transcriptional repression and LON-dependent turnover of the mitochondrial pre-RNA processing nuclease MRPP3. This study reveals that acute mitochondrial protein folding stress activates both increased chaperone availability within the matrix and reduced matrix-localized protein synthesis through translational inhibition, and provides a framework for further dissection of mammalian UPRmt.
2016-06-28 | GSE75410 | GEO
Project description:The mitochondrial matrix is unique in that it must integrate folding and assembly of proteins derived from nuclear and mitochondrial genomes. In C. elegans, the mitochondrial unfolded protein response (UPRmt) senses matrix protein misfolding and induces a program of nuclear gene expression, including mitochondrial chaperonins, to promote mitochondrial proteostasis. While misfolded mitochondrial matrix-localized ornithine trans-carbamylase (OTC) induces chaperonin expression, our understanding of mammalian UPRmt is rudimentary, reflecting a lack of acute triggers for UPRmt activation. This limitation has prevented analysis of the cellular responses to matrix protein misfolding and the effects of UPRmt on mitochondrial translation to control protein folding loads. Here, we combine pharmacological inhibitors of matrix-localized HSP90/TRAP1 or LON protease, which promote chaperonin expression, with global transcriptional and proteomic analysis to reveal an extensive and acute response of human cells to UPRmt. This response involved widespread induction of nuclear genes, including matrix-localized proteins involved in folding, pre-RNA processing and translation. Functional studies revealed rapid but reversible translation inhibition in mitochondria occurring concurrently with defects in pre-RNA processing due to transcriptional repression and LON-dependent turnover of the mitochondrial pre-RNA processing nuclease MRPP3. This study reveals that acute mitochondrial protein folding stress activates both increased chaperone availability within the matrix and reduced matrix-localized protein synthesis through translational inhibition, and provides a framework for further dissection of mammalian UPRmt.
2016-06-28 | GSE75247 | GEO