Role of RhoGAP Rgd1 in Pkc1 signaling-related actin repolarization under heat shock stress in Saccharomyces cerevisiae

2021 ◽  
Vol 1865 (5) ◽  
pp. 129853
Author(s):  
Wataru Nomura ◽  
Ryota Futamata ◽  
Yoshiharu Inoue
2000 ◽  
Vol 352 (1) ◽  
pp. 71-78 ◽  
Author(s):  
Kei-ichi SUGIYAMA ◽  
Atsuki KAWAMURA ◽  
Shingo IZAWA ◽  
Yoshiharu INOUE

Previously we reported that expression of GSH1 (γ-glutamylcysteine synthetase) and GSH2 (glutathione synthetase) of the yeast Saccharomyces cerevisiae was increased by heat-shock stress in a Yap1p-dependent fashion and consequently intracellular glutathione content was increased [Sugiyama, Izawa and Inoue (2000) J. Biol. Chem. 275, 15535–15540]. In the present study, we discuss the physiological role of glutathione in the heat-shock stress response in this yeast. Both gsh1 and gsh2 mutants could acquire thermotolerance by mild heat-shock stress and induction of Hsp104p in both mutants was normal; however, mutant cells died faster by heat shock than their parental wild-type strain. After pretreatment at a sublethal temperature, the number of respiration-deficient mutants increased in a gsh1 mutant strain in the early stages of exposure to a lethal temperature, although this increase was partially suppressed by the addition of glutathione. These results lead us to suspect that an increase of glutathione synthesis during heat-shock stress is to protect mitochondrial DNA from oxidative damage. To investigate the correlation between mitochondrial DNA damage and glutathione, mitochondrial Mn-superoxide dismutase (the SOD2 gene product) was disrupted. As a result, the rate of generation of respiration-deficient mutants of a sod2∆ strain was higher than that of the isogenic wild-type strain and treatment of the sod2∆ mutant with buthionine sulphoximine, an inhibitor of glutathione synthesis, inhibited cell growth. These results suggest that glutathione synthesis is induced by heat shock to protect the mitochondrial DNA from oxidative damage that may lead to cell death.


1993 ◽  
Vol 13 (1) ◽  
pp. 248-256
Author(s):  
N Kobayashi ◽  
K McEntee

The stress-responsive DDR2 gene (previously called DDRA2) of Saccharomyces cerevisiae is transcribed at elevated levels following stress caused by heat shock or DNA damage. Previously, we identified a 51-bp promoter fragment, oligo31/32, which conferred heat shock inducibility on the heterologous CYC1-lacZ reporter gene in S. cerevisiae (N. Kobayashi and K. McEntee, Proc. Natl. Acad. Sci. USA 87:6550-6554, 1990). Using a series of synthetic oligonucleotides, we have identified a pentanucleotide, CCCCT (C4T), as an essential component of this stress response sequence. This element is not a binding site for the well-characterized heat shock transcription factor which recognizes a distinct cis-acting heat shock element in the promoters of many heat shock genes. Here we demonstrate the ability of oligonucleotides containing the C4T sequence to confer heat shock inducibility on the reporter gene and show that the presence of two such elements produces more than additive effects on induction. Gel retardation experiments have been used to demonstrate specific complex formation between C4T-containing fragments and one or more yeast proteins. Formation of these complexes was not competed by fragments containing mutations in the C4T sequence nor by heat shock element-containing competitor DNAs. Fragments containing the C4T element bound to a single 140-kDa polypeptide, distinct from heat shock transcription factors in yeast crude extracts. These experiments identify key cis- and trans-acting components of a novel heat shock stress response pathway in S. cerevisiae.


1993 ◽  
Vol 13 (1) ◽  
pp. 248-256 ◽  
Author(s):  
N Kobayashi ◽  
K McEntee

The stress-responsive DDR2 gene (previously called DDRA2) of Saccharomyces cerevisiae is transcribed at elevated levels following stress caused by heat shock or DNA damage. Previously, we identified a 51-bp promoter fragment, oligo31/32, which conferred heat shock inducibility on the heterologous CYC1-lacZ reporter gene in S. cerevisiae (N. Kobayashi and K. McEntee, Proc. Natl. Acad. Sci. USA 87:6550-6554, 1990). Using a series of synthetic oligonucleotides, we have identified a pentanucleotide, CCCCT (C4T), as an essential component of this stress response sequence. This element is not a binding site for the well-characterized heat shock transcription factor which recognizes a distinct cis-acting heat shock element in the promoters of many heat shock genes. Here we demonstrate the ability of oligonucleotides containing the C4T sequence to confer heat shock inducibility on the reporter gene and show that the presence of two such elements produces more than additive effects on induction. Gel retardation experiments have been used to demonstrate specific complex formation between C4T-containing fragments and one or more yeast proteins. Formation of these complexes was not competed by fragments containing mutations in the C4T sequence nor by heat shock element-containing competitor DNAs. Fragments containing the C4T element bound to a single 140-kDa polypeptide, distinct from heat shock transcription factors in yeast crude extracts. These experiments identify key cis- and trans-acting components of a novel heat shock stress response pathway in S. cerevisiae.


2018 ◽  
Author(s):  
Ugo Cappucci ◽  
Fabrizia Noro ◽  
Assunta Maria Casale ◽  
Laura Fanti ◽  
Maria Berloco ◽  
...  

AbstractPrevious studies have shown that heat shock stress may increase transcription levels and, in some cases, also the transposition of certain transposable elements (TEs) in Drosophila and other organisms. Other studies have also demonstrated that heat shock chaperones as Hsp90 and Hop are involved in repressing transposon’s activity in Drosophila melanogaster by their involvement in crucial steps of the biogenesis of Piwi-interacting RNAs (piRNAs), the largest class of germline-enriched small non-coding RNA implicated in the epigenetic silencing of TEs. However, a satisfying picture of how many chaperones and their respective functional roles could be involved in repressing transposons in germ cell is still unknown. Here we show that in Drosophila heat shock activates transposon′s expression at post-transcriptional level by disrupting a repressive chaperone complex by a decisive role of the stress-inducible chaperone Hsp70. We found that stress-induced transposons activation is triggered by an interaction of Hsp70 with the Hsc70-Hsp90 complex and other factors all involved in piRNA biogenesis in both ovaries and testes. Such interaction induces a displacement of all such factors to the lysosomes resulting in a functional collapse of piRNA biogenesis. In support of a significant role of Hsp70 in transposon activation after stress, we found that the expression under normal conditions of Hsp70 in transgenic flies increases the amount of transposon transcripts and displaces the components of chaperon machinery outside the nuage as observed after heat shock. So that, our results demonstrate that heat shock stress is capable to increase the expression of transposons at post-transcriptional level by affecting piRNA biogenesis through the action of the inducible chaperone Hsp70. We think that such mechanism proposes relevant evolutionary implications. In presence of drastic environmental changes, Hsp70 plays a key dual role in increasing both the survival probability of individuals and the genetic variability in their germ cells. This in turn should be translated into an increase of genetic variability inside the populations thus potentiating their evolutionary plasticity and evolvability.


2021 ◽  
Author(s):  
Avishek Roy ◽  
Ranjan Tamuli

Abstract Heat shock proteins (Hsps) are molecular chaperones and required for survival of organisms under heat stress conditions. In this study, we studied Hsp80, a member of the Hsp90 family, in Neurospora crassa. The expression of hsp80 was severely reduced in the N. crassa calcineurin B subunit RIP-mutant (cnb-1RIP) strains under the heat shock conditions. Furthermore, the expression levels of cnb-1, hsp60, hsp80, and the calcineurin-regulated transcription factor crz-1 were increased, but expression levels were reduced in the presence of the calcineurin inhibitor FK506 under the heat shock stress in the N. crassa wild type. Therefore, the calcineurin-crz-1 signaling pathway transcriptionally regulates hsp60 and hsp80 under the heat shock stress condition in N. crassa. In addition, the transcript levels of trm-9 and nca-2, a Ca2+ sensor and a Ca2+ ATPase, respectively, were increased under the heat shock stress condition. Moreover, the expression of the hsp80, but not the hsp60, was reduced in the Δtrm-9, Δnca-2, and the Δtrm-9 Δnca-2 double mutants. These results suggested that hsp80, trm-9, and nca-2 play a role in coping the heat shock stress in N. crassa. We found that CRZ-1 binds to 5ʹ-CCTTCACA-3ʹ and 5ʹ-AGCGGAGC-3ʹ 8 bp nucleotide sequences, located about 1075 bp and 679 bp upstream of the ATG start codon, respectively, of hsp80. We also found that CRZ-1 binds to an 8 bp nucleotide sequence 5ʹ-ACCGCGCC-3ʹ, located 234 bp upstream of the ATG start codon of nca-2 under Ca2+ stress condition. Thus, cnb-1, hsp60, hsp80, and crz-1 are involved in the heat shock stress response in N. crassa. Moreover, CRZ-1 upregulates the expressions of hsp80 and nca-2 under the heat shock stress and Ca2+ stress conditions, respectively, in N. crassa.


2015 ◽  
Vol 112 (42) ◽  
pp. E5669-E5678 ◽  
Author(s):  
Neri Minsky ◽  
Robert G. Roeder

In recent years an extensive effort has been made to elucidate the molecular pathways involved in metabolic signaling in health and disease. Here we show, surprisingly, that metabolic regulation and the heat-shock/stress response are directly linked. Peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α), a critical transcriptional coactivator of metabolic genes, acts as a direct transcriptional repressor of heat-shock factor 1 (HSF1), a key regulator of the heat-shock/stress response. Our findings reveal that heat-shock protein (HSP) gene expression is suppressed during fasting in mouse liver and in primary hepatocytes dependent on PGC-1α. HSF1 and PGC-1α associate physically and are colocalized on several HSP promoters. These observations are extended to several cancer cell lines in which PGC-1α is shown to repress the ability of HSF1 to activate gene-expression programs necessary for cancer survival. Our study reveals a surprising direct link between two major cellular transcriptional networks, highlighting a previously unrecognized facet of the activity of the central metabolic regulator PGC-1α beyond its well-established ability to boost metabolic genes via its interactions with nuclear hormone receptors and nuclear respiratory factors. Our data point to PGC-1α as a critical repressor of HSF1-mediated transcriptional programs, a finding with possible implications both for our understanding of the full scope of metabolically regulated target genes in vivo and, conceivably, for therapeutics.


2010 ◽  
Vol 30 (21) ◽  
pp. 5168-5179 ◽  
Author(s):  
Sean R. Carmody ◽  
Elizabeth J. Tran ◽  
Luciano H. Apponi ◽  
Anita H. Corbett ◽  
Susan R. Wente

ABSTRACT Cellular adaptation to environmental stress conditions requires rapid and specific changes in gene expression. During heat shock, most polyadenylated mRNAs are retained in the nucleus, whereas the export of heat shock-induced mRNAs is allowed. Although essential mRNA export factors are known, the precise mechanism for regulating transport is not fully understood. Here we find that during heat shock in Saccharomyces cerevisiae, the mRNA-binding protein Nab2 is phosphorylated on threonine 178 and serine 180 by the mitogen-activated protein (MAP) kinase Slt2/Mpk1. Slt2 is required for nuclear poly(A+) mRNA accumulation upon heat shock, and thermotolerance is decreased in a nup42 nab2-T178A/S180A mutant. Coincident with phosphorylation, Nab2 and Yra1 colocalize in nuclear foci with Mlp1, a protein involved in mRNA retention. Nab2 nuclear focus formation and Nab2 phosphorylation are independent, suggesting that heat shock induces multiple cellular alterations that impinge upon transport efficiency. Under normal conditions, we find that the mRNA export receptor Mex67 and Nab2 directly interact. However, upon heat shock stress, Mex67 does not localize to the Mlp1 nuclear foci, and its association with Nab2 complexes is reduced. These results reveal a novel mechanism by which the MAP kinase Slt2 and Mlp1 control mRNA export factors during heat shock stress.


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