Disruption of the Nα-acetyltransferase NatB causes sensitivity to reductive stress in Arabidopsis thaliana
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PROVIDER: PRJNA773404 | ENA |
REPOSITORIES: ENA
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Project description:In Arabidopsis thaliana the evolutionary conserved N-terminal acetyltransferase (Nat) complexes NatA and NatB co-translationally acetylate 60% of the proteome. Both have recently been implicated in the regulation of plant stress responses. While NatA mediates drought tolerance, NatB is required for pathogen resistance and the adaptation to high salinity and high osmolarity. Salt and osmotic stress impair protein folding and result in the accumulation of misfolded proteins in the endoplasmic reticulum (ER). The ER-membrane resident E3 ubiquitin ligase DOA10 targets misfolded proteins for degradation during ER stress and is conserved among eukaryotes. In yeast, DOA10 recognizes conditional degradation signals (Ac/N-degrons) created by NatA and NatB. Assuming that this mechanism is preserved in plants, the lack of Ac/N-degrons required for efficient removal of misfolded proteins might explain the sensitivity of NatB mutants to protein harming conditions. In this study, we investigate the response of NatB mutants to dithiothreitol (DTT) and tunicamycin (TM) induced ER stress. We report that NatB mutants are hypersensitive to DTT but not TM, suggesting that the DTT hypersensitivity is caused by an over-reduction of the cytosol rather than an accumulation of unfolded proteins in the ER. In line with this hypothesis, the cytosol of NatB depleted plants is constitutively over-reduced and a global transcriptome analysis reveals that their reductive stress response is permanently activated. Moreover, we demonstrate that doa10 mutants are susceptible to neither DTT nor TM, ruling out a substantial role of DOA10 in ER-associated protein degradation (ERAD) in plants. Contrary to previous findings in yeast, our data indicates that N-terminal acetylation (NTA) does not inhibit ER targeting of a substantial amount of proteins in plants. In summary, we provide further evidence that NatB-mediated imprinting of the proteome is vital for the response to protein-harming stress and rule out DOA10 as the sole recognin for substrates in the plant ERAD pathway.
2021-11-29 | GSE186324 | GEO
Project description:Search for genes differently expressed when we inhibit NatB N-terminal acetyltransferase. We compare gene expression after inhibiting hNAT5 expression in Hela cells with specific siRNAs expressed with adenoviruses. Keywords: gene expression comparison
2008-03-12 | GSE10779 | GEO
Project description: Not available
| S-EPMC8761761 | biostudies-literature
Project description:Search for genes differently expressed when we inhibit NatB N-terminal acetyltransferase. We compare gene expression after inhibiting hNAT5 expression in Hela cells with specific siRNAs expressed with adenoviruses. Experiment Overall Design: We analyzed duplicate samples and we used as controls Hela cells and Hela cells that express a siRNA that doesn't inhibit any gene expression. Experiment Overall Design: The N-terminal acetyltransferase NatB, composed in Saccharomyces cerevisiae by the Nat3p and Mdm20p subunits, is an important factor for yeast growth and resistance to several stress agents. However, the expression and functional role of the mammalian counterpart has not yet been analysed. Here, we report the identification of Nat3p human homologue (hNAT5/hNAT3) and the characterization of its biological function. We found that hNAT5/hNAT3 silencing in HeLa cells results in inhibition of cell proliferation and increased sensitivity to the proapoptotic agent MG132. Moreover, inhibition of hNAT5/hNAT3 expression induces p53 activation and upregulation of the antiproliferative protein p21(WAF1/CIP1). The changes of the cellular transcriptome after hNAT5/hNAT3 knockdown confirmed the involvement of this protein in cell growth and survival processes. Among the genes differentially expressed we observed upregulation of several p53-dependent antiproliferative and proapoptotic genes. In the c-myc transgenic mice which is a model of inducible hepatocarcinoma we found that hNAT5/hNAT3 was upregulated when the tumor was induced. In accordance with this observation we noticed increased hNAT5/hNAT3 protein level in neoplastic versus non-neoplastic tissue in a high proportion of patients with hepatocellular carcinoma. Consequently, our results suggest that the expression of the protein hNAT5/hNAT3 is required for cellular proliferation and tumor growth.
2008-04-05 | E-GEOD-10779 | biostudies-arrayexpress
Project description:NatB N-terminal acetyltransferase (hNAT5) inhibition
| PRJNA107461 | ENA
Project description:Metazoan organisms rely on conserved stress response pathways to detect and alleviate adverse conditions and preserve their cellular integrity. Stress responses are particularly important in stem cells that provide lifetime support for tissue formation and repair, yet how these protective systems are integrated into developmental programs is poorly understood. Here, we have used myoblast differentiation to identify the E3 ligase CUL2FEM1B and its substrate FNIP1 as core components of the reductive stress response. Reductive stress, as caused by prolonged antioxidant signaling or mitochondrial inactivity, reverts the oxidation of invariant Cys residues in FNIP1 and thereby allows CUL2FEM1B to recognize its target. The ensuing proteasomal degradation of FNIP1 restores mitochondrial activity to preserve both redox homeostasis and stem cell integrity. The reductive stress response is therefore built around a ubiquitin-dependent rheostat that tunes mitochondrial activity to cellular redox needs and implicates metabolic control in the coordination of stress and developmental signaling.
2020-07-30 | GSE155374 | GEO
Project description:Type 2 diabetes is a complex disorder due to defects in insulin secretion and insulin action. Therefore, we investigated mice overexpressing spermidine/spermine N1-acetyltransferase (SSAT) have reduced amount of white adipose tissue, high basal metabolic rate, improved glucose tolerance, high insulin sensitivity, and a low accumulation of triglycerides in liver and skeletal muscle. Our aim was to elucidate the molecular mechanisms leading to the phenotype of SSAT mice.
2007-04-25 | E-MEXP-165 | biostudies-arrayexpress
Project description:Galactose catabolism in Aspergillus nidulans is regulated by at least two regulators, GalR and GalX. In Aspergillus niger only GalX is present, and its role in D-galactose catabolism in this fungus was investigated. Phenotypic and gene expression analysis of a wild type and a galX disruptant revealed that GalX does not substitute for the absence of GalR in A. niger, it regulates the D-galactose oxido-reductive pathway, but not the Leloir pathway. Four genes, including the recently characterized ladB (galactitol dehydrogenase) were found to have differencial expressions that are highly relevant to GalX , indicating a novel oxido-reductive pathway in A.niger .
2012-09-20 | GSE40219 | GEO
Project description:Galactose catabolism in Aspergillus nidulans is regulated by at least two regulators, GalR and GalX. In Aspergillus niger only GalX is present, and its role in D-galactose catabolism in this fungus was investigated. Phenotypic and gene expression analysis of a wild type and a galX disruptant revealed that GalX does not substitute for the absence of GalR in A. niger, it regulates the D-galactose oxido-reductive pathway, but not the Leloir pathway. Four genes, including the recently characterized ladB (galactitol dehydrogenase) were found to have differencial expressions that are highly relevant to GalX , indicating a novel oxido-reductive pathway in A.niger . We aim to discover differentially expressed genes in A.niger wild type strain N402 and M-NM-^TgalX mutant while growing on galactose as carbon source. Biological duplicates were made for both strains. The strains were grown O/N in complete medium with 2% frunctose and mycelium was then washed and transferred to minimal medium with 25 mM D-galactose and incubated for 2 hours. Affymetrix microarray experiments were performed RNA isolated from these samples.
2012-09-20 | E-GEOD-40219 | biostudies-arrayexpress
Project description:Elevated Endothelial Sox2 Causes Lumen Disruption and Cerebral AVMs
| PRJNA532381 | ENA