Control of protein accumulation by LON2 peroxisomal protease and autophagy
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ABSTRACT:
PROVIDER: PRJNA858078 | ENA |
REPOSITORIES: ENA
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Project description:Peroxisomes are membrane-bound eukaryotic organelles that house essential metabolic pathways. Many of these pathways generate damaging reactive oxygen species (ROS) that also function as signaling molecules. In Arabidopsis thaliana, damaged or obsolete peroxisomal proteins can be degraded by the LON2 peroxisomal protease. In addition, peroxisomes can be entirely degraded through a specialized form of autophagy (pexophagy), a process that is amplified when LON2 is dysfunctional. As a first step towards surveying the transcriptional landscape of dysfunctional LON2 , we used RNA-seq analysis to compare transcript that are induced and reduced when LON2 is dysfunctional in the presence and absence of autophagy.
2024-12-27 | GSE208057 | GEO
Project description:Protein quality control is important for healthy aging and is dysregulated in several age-related diseases. The autophagy-lysosome and ubiquitin-proteasome systems are key for proteostasis but it remains largely unknown whether other proteolytic systems maintain protein quality control during aging. Here, we find that the expression of proteolytic enzymes (proteases/peptidases) distinct from the autophagy-lysosome and ubiquitin-proteasome systems declines during skeletal muscle aging in Drosophila. Age-dependent downregulation of proteases undermines proteostasis, as demonstrated by the increase in detergent-insoluble poly-ubiquitinated proteins and pathogenic huntingtin-polyQ in response to protease RNAi. Transcriptomic analysis identifies Ptx1, homologous to human PITX1/2/3, as a transcriptional regulator of proteases. Specifically, RNAi for Ptx1 increases the expression of age-downregulated proteases and improves protein quality. Moreover, muscle-specific expression of Ptx1 RNAi extends lifespan. These findings indicate that protein quality control is ensured during aging by autophagy/proteasome-independent proteases that degrade misfolded and aggregation-prone proteins and by their transcriptional modulator Ptx1.
2022-08-15 | GSE156346 | GEO
Project description:FES1a is an auxiliary molecular chaperone of heat shock protein 70 (HSP70), and the fes1a mutant is defective in acquired thermotolerance. As an efficient clearance pathway, autophagy is a positive regulator of basal thermotolerance and a negative regulator of heat stress memory, but its function in acquired thermotolerance is unclear. Proteomic analysis revealed that blocking constitutive autophagy leads to the accumulation of peroxisomes and related metabolic pathways within the peroxisomes.
2025-01-17 | PXD050259 | Pride
Project description:Distinct retrograde signaling pathways have been identified for several cellular organelles. These pathways are important to maintain the function of these organelles in response to organelle-specific stress. Using Caenorhabditis elegans, we show for the first time that such a retrograde signaling also exists for peroxisomes. Analysis of the C. elegans transcriptome revealed that peroxisomal import stress caused by the knock-down of the peroxisomal matrix protein import receptor prx-5/PEX5 induces the compensatory up-regulation of genes involved in defense response and lipid metabolic processes, especially peroxisomal beta oxidation. We, therefore, propose that the peroxisomal retrograde signaling participates in the maintenance of peroxisomal function in response to peroxisomal import stress.
2020-12-19 | GSE156318 | GEO
Project description:Many neurodegenerative diseases are characterized by the presence of intracellular protein aggregates resulting in alterations in autophagy. However, the consequences of impaired autophagy on neuronal function remain poorly understood. In this study, we used cell culture and mouse models of huntingtin protein aggregation, as well as post-mortem material from patients with Huntington's disease to demonstrate that Argonaute-2 (AGO2) accumulates in the presence of neuronal protein aggregates and that this is due to impaired autophagy. Accumulation of AGO2, a key factor of the RNAinduced silencing complex that executes microRNA functions, results in global alterations of microRNA levels and activity. Together these results demonstrate that impaired autophagy found in neurodegenerative diseases not only influences protein aggregation, but also directly contributes to global alterations of intracellular posttranscriptional networks.
2018-08-07 | GSE78928 | GEO
Project description:Autophagy to apoptosis switching event is an unexplored area. We were interested to explore the gene expression profile at this juncture. Our Microarray data emphasized that among all eNOS and p62 genes were markedly induced. In fuctional level eNOS expression activates mTORC1 followed by inhibition of autophagy. This ultimately allowed accumulation of p62 . Intraccellular accumulation of p62 sequestered unfolded toxic protein aggregates in mitochondria and ER resulting in to impaired redox regulation. Intraccelular ROS generation further sensitized cells for apoptosis and tilted autophagic response to apoptosis. Cells were treated with Tunicamycin as an inducer of both autophagy and apoptosis. At early stage of Tunicamycin treatment 24h , prostate cancer cell PC3 showed activation of autophagic process where apoptosis was not evident. Sustained ER stress with Tunicamycin induced late apoptoisis at 72h of treatment. Hence we isolated total RNA from Untreated cells, cells with Tunicamycin treatment after 24h and 72h. Further the RNA were used to perform whole genome microarray to analyze the gene expression profile at autophagy and apoptosis juncture. The selected genes were also validated by qPCR and western bot. Morover RNAi study were implemented to evaluate the signaling crosstalk at the juncture of autophagy and apoptosis.
2014-05-22 | E-GEOD-38643 | biostudies-arrayexpress
Project description:Hydrogen sulfide is a signaling molecule that regulates essential processes for plant performance, such as autophagy. In Arabidopsis thaliana, hydrogen sulfide negatively regulates autophagy independently of reactive oxygen species, but the underlying mechanism remains to be understood. To determine whether persulfidation, an emergent posttranslational modification, has a main role in the control of autophagy by sulfide, we have used a proteomic approach targeting ATG4, a cysteine protease that plays a crucial role in autophagy progression. We showed that AtATG4a from A. thaliana, which is the predominant ATG4 protease in this plant species, contains a specific site for persulfidation, the residue Cys170, included in the characteristic catalytic triad Cys-His-Asp of cysteine proteases. We tested whether persulfidation regulates the activity of ATG4 by setting up a heterologous assay using the Chlamydomonas reinhardtii CrATG8 protein as a substrate. Our findings demonstrate that sulfide significantly inactivates AtATG4a cleavage activity in a reversible manner. The biological significance of the reversible inhibition of the ATG4 protease by sulfide is supported by our findings in Arabidopsis leaves under both basal and autophagy-inducing conditions. We also observed a significant increase in the overall ATG4 activity in Arabidopsis under nitrogen starvation and osmotic stress, which is inhibited by sulfide. Therefore, our data strongly suggest that the negative regulation of autophagy by sulfide is mediated, at least, by the specific persulfidation of the protease ATG4.
2020-12-14 | PXD019802 | Pride
Project description:Serine protease inhibitor Kazal type 3 (Spink3) is a trypsin inhibitor in the pancreas. Spink3-/- pancreatic acinar cells are dead with excessive autophagy at birth (p0.5). To prove the role of nonapoptotic cell death with autophagy, we generated by transgenic technology the pancreas of Spink3-/-;XKI/+ mice contained both normal and dying acinar cells with autophagy. In this new mouse model, chronic inflammation occurred in the pancreas, indicating that some signals from nonapoptotic dead cell induce chronic inflammation in the pancreas. All samples were the pancreas at p0.5. Sample 1 and 2 are the pancreas from wild type (Spink3+/+, control) mice. Sample 3 and 4 are the pancreas from Spink3-/-, which all pancreatic acinar cells show induced nonapoptotic cell death with autophagy. Sample 5 and 6 are the pancreas from Spink3-/-XKI/+, about half acinar cells are normal, but other acinar cells show induced nonapoptotic cell death with autophagy.
2016-07-16 | E-GEOD-48946 | biostudies-arrayexpress
Project description:Developmental and homeostatic remodeling of cellular organelles is mediated by a complex process termed autophagy. The cohort of proteins that constitute the autophagy machinery function in a multistep biochemical pathway. Though components of the autophagy machinery are broadly expressed, autophagy can occur in specialized cellular contexts, and mechanisms underlying cell type-specific autophagy are poorly understood. We demonstrate that the master regulator of hematopoiesis GATA-1 directly activates transcription of genes encoding the essential autophagy component Microtubule Associated Protein 1 Light Chain 3B (LC3B) and its homologs (MAP1LC3A, GABARAP, GABARAPL1, GATE-16). In addition, GATA-1 directly activates genes involved in the biogenesis/function of lysosomes, which mediate autophagic protein turnover. We demonstrate that GATA-1 utilizes the forkhead protein FoxO3 to activate select autophagy genes. GATA-1-dependent LC3B induction is tightly coupled to accumulation of the active form of LC3B and autophagosomes, which mediate mitochondrial clearance as a critical step in erythropoiesis. These results illustrate a novel mechanism by which a master regulator of development establishes a genetic network to instigate cell type-specific autophagy. Genome-wide maps of GATA1 factor occupancy in primary human PBMC derived erythroblasts
2011-09-30 | E-GEOD-32491 | biostudies-arrayexpress
Project description:PEX13 is an integral membrane protein on the peroxisome that regulates peroxisomal matrix protein import during peroxisome biogenesis. Mutations in PEX13 and other peroxin proteins are associated with Zellweger syndrome spectrum (ZSS) disorders, a subtype of peroxisome biogenesis disorder characterized by prominent neurological, hepatic, and renal abnormalities leading to neonatal death. The lack of functional peroxisomes in ZSS patients is widely accepted as the underlying cause of disease; however, our understanding of disease pathogenesis is still incomplete. Here, we demonstrate that PEX13 is required for selective autophagy of Sindbis virus (virophagy) and of damaged mitochondria (mitophagy) and that disease-associated PEX13 mutants I326T and W313G are defective in mitophagy. The mitophagy function of PEX13 is shared with another peroxin family member PEX3, but not with two other peroxins, PEX14 and PEX19, which are required for general autophagy. Together, our results demonstrate that PEX13 is required for selective autophagy, and suggest that dysregulation of PEX13-mediated mitophagy may contribute to ZSS pathogenesis.
| S-EPMC5210156 | biostudies-literature