scholarly journals Fission Yeast Mitogen-Activated Protein Kinase Sty1 Interacts with Translation Factors

2007 ◽  
Vol 7 (2) ◽  
pp. 328-338 ◽  
Author(s):  
Eva Asp ◽  
Daniel Nilsson ◽  
Per Sunnerhagen
Keyword(s):  
Oxidative Stress ◽  
Protein Kinase ◽  
Fission Yeast ◽  
Elongation Factor ◽  
Mitogen Activated Protein Kinase ◽  
Initiation Factor ◽  
Translation Efficiency ◽  
Nitrogen Deprivation ◽  
Hyperosmotic Shock ◽  
Mitogen Activated Protein

ABSTRACT Signaling by stress-activated mitogen-activated protein kinase (MAPK) pathways influences translation efficiency in mammalian cells and budding yeast. We have investigated the stress-activated MAPK from fission yeast, Sty1, and its downstream protein kinase, Mkp1/Srk1, for physically associated proteins using tandem affinity purification tagging. We find Sty1, but not Mkp1, to bind to the translation elongation factor eukaryotic elongation factor 2 (eEF2) and the translation initiation factor eukaryotic initiation factor 3a (eIF3a). The Sty1-eIF3a interaction is weakened under oxidative or hyperosmotic stress, whereas the Sty1-eEF2 interaction is stable. Nitrogen deprivation causes a transient strengthening of both the Sty1-eEF2 and the Sty1-Mkp1 interactions, overlapping with the time of maximal Sty1 activation. Analysis of polysome profiles from cells under oxidative stress, or after hyperosmotic shock or nitrogen deprivation, shows that translation in sty1 mutant cells recovers considerably less efficiently than that in the wild type. Cells lacking the Sty1-regulated transcription factor Atf1 are deficient in maintaining and recovering translational activity after hyperosmotic shock but not during oxidative stress or nitrogen starvation. In cells lacking Sty1, eIF3a levels are decreased, and phosphorylation of eIF3a is reduced. Taken together, our data point to a central role in translational adaptation for the stress-activated MAPK pathway in fission yeast similar to that in other investigated eukaryotes, with the exception that fission yeast MAPK-activated protein kinases seem not to be directly involved in this process.

scholarly journals Role of Mitogen-Activated Protein Kinase Sty1 in Regulation of Eukaryotic Initiation Factor 2α Kinases in Response to Environmental Stress in Schizosaccharomyces pombe

2009 ◽  
Vol 9 (1) ◽  
pp. 194-207 ◽  
Author(s):  
Juan José Berlanga ◽  
Damariz Rivero ◽  
Ruth Martín ◽  
Saturnino Herrero ◽  
Sergio Moreno ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Heat Shock ◽  
Protein Kinase ◽  
Schizosaccharomyces Pombe ◽  
Mitogen Activated Protein Kinase ◽  
Initiation Factor ◽  
Eukaryotic Initiation Factor ◽  
Transcriptional Responses ◽  
Mitogen Activated Protein ◽  
Eif2α Kinase

ABSTRACT The mitogen-activated protein kinase (MAPK) Sty1 is essential for the regulation of transcriptional responses that promote cell survival in response to different types of environmental stimuli in Schizosaccharomyces pombe. In fission yeast, three distinct eukaryotic initiation factor 2α (eIF2α) kinases, two mammalian HRI-related protein kinases (Hri1 and Hri2) and the Gcn2 ortholog, regulate protein synthesis in response to cellular stress conditions. In this study, we demonstrate that both Hri1 and Hri2 exhibited an autokinase activity, specifically phosphorylated eIF2α, and functionally replaced the endogenous Saccharomyces cerevisiae Gcn2. We further show that Gcn2, but not Hri1 or Hri2, is activated early after exposure to hydrogen peroxide and methyl methanesulfonate (MMS). Cells lacking Gcn2 exhibit a later activation of Hri2. The activated MAPK Sty1 negatively regulates Gcn2 and Hri2 activities under oxidative stress but not in response to MMS. In contrast, Hri2 is the primary activated eIF2α kinase in response to heat shock. In this case, the activation of Sty1 appears to be transitory and does not contribute to the modulation of the eIF2α kinase stress pathway. In strains lacking Hri2, a type 2A protein phosphatase is activated soon after heat shock to reduce eIF2α phosphorylation. Finally, the MAPK Sty1, but not the eIF2α kinases, is essential for survival upon oxidative stress or heat shock, but not upon MMS treatment. These findings point to a regulatory coordination between the Sty1 MAPK and eIF2α kinase pathways for a particular range of stress responses.

Age-Related Changes in Activation of Mitogen-Activated Protein Kinase Cascades by Oxidative Stress

1998 ◽  
Vol 3 (1) ◽  
pp. 23-27 ◽  
Author(s):  
Kathryn Z Guyton ◽  
Myriani Gorospe ◽  
Xiantao Wang ◽  
Yolanda D Mock ◽  
Gertrude C Kokkonen ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Protein Kinase ◽  
Mitogen Activated Protein Kinase ◽  
Age Related ◽  
Mitogen Activated Protein ◽  
Age Related Changes

scholarly journals A Redox-Sensitive Thiol in Wis1 Modulates the Fission Yeast Mitogen-Activated Protein Kinase Response to H2O2 and Is the Target of a Small Molecule

2020 ◽  
Vol 40 (7) ◽  
Author(s):  
Johanna J. Sjölander ◽  
Agata Tarczykowska ◽  
Cecilia Picazo ◽  
Itziar Cossio ◽  
Itedale Namro Redwan ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Fission Yeast ◽  
Inhibitory Effect ◽  
Mitogen Activated Protein Kinase ◽  
Activation Loop ◽  
Content Type ◽  
Kinase Activation ◽  
Mitogen Activated Protein

ABSTRACT Oxidation of a highly conserved cysteine (Cys) residue located in the kinase activation loop of mitogen-activated protein kinase kinases (MAPKK) inactivates mammalian MKK6. This residue is conserved in the fission yeast Schizosaccharomyces pombe MAPKK Wis1, which belongs to the H2O2-responsive MAPK Sty1 pathway. Here, we show that H2O2 reversibly inactivates Wis1 through this residue (C458) in vitro. We found that C458 is oxidized in vivo and that serine replacement of this residue significantly enhances Wis1 activation upon addition of H2O2. The allosteric MAPKK inhibitor INR119, which binds in a pocket next to the activation loop and C458, prevented the inhibition of Wis1 by H2O2 in vitro and significantly increased Wis1 activation by low levels of H2O2 in vivo. We propose that oxidation of C458 inhibits Wis1 and that INR119 cancels out this inhibitory effect by binding close to this residue. Kinase inhibition through the oxidation of a conserved Cys residue in MKK6 (C196) is thus conserved in the S. pombe MAPKK Wis1.

scholarly journals Oxidative stress inhibits MEKK1 by site-specific glutathionylation in the ATP-binding domain

2004 ◽  
Vol 381 (3) ◽  
pp. 675-683 ◽  
Author(s):  
Janet V. CROSS ◽  
Dennis J. TEMPLETON
Keyword(s):  
Oxidative Stress ◽  
Protein Kinase ◽  
Cysteine Residue ◽  
Binding Domain ◽  
Mitogen Activated Protein Kinase ◽  
Atp Binding ◽  
Cysteine Oxidation ◽  
Mitogen Activated Protein ◽  
In Cells

Many intracellular signalling events are accompanied by generation of reactive oxygen species in cells. Oxidation of protein thiol groups is an emerging theme in signal-transduction research. We have found that MEKK1 [MAPK (mitogen-activated protein kinase)/ERK (extracellular-signal-regulated kinase) kinase kinase 1], an upstream activator of the SAPK/JNK (stress-activated protein kinase/c-Jun N-terminal kinase) pathway, is directly inhibited by cysteine alkylation using NEM (N-ethylmaleimide). The related kinase, ASK1 (apoptosis signal-regulating kinase 1), was not inhibited, but was instead activated by NEM. Inhibition of MEKK1 requires a single unique cysteine residue (Cys1238) in the ATP-binding domain of MEKK1. Oxidative stress induced by menadione (2-methyl-1,4-naphthoquinone) also inhibited MEKK1, but activated ASK1, in cells. MEKK1 inhibition by menadione also required Cys1238. Oxidant-inhibited MEKK1 was re-activated by dithiothreitol and glutathione, supporting reversible cysteine oxidation as a mechanism. Using various chemical probes, we excluded modification by S-nitrosylation or oxidation of cysteine to sulphenic acid. Oxidant-inhibited MEKK1 migrated normally on non-reducing gels, excluding the possibility of intra- or inter-molecular disulphide bond formation. MEKK1 was inhibited by glutathionylation in vitro, and MEKK1 isolated from menadione-treated cells was shown by MS to be modified by glutathione on Cys1238. Our results support a model whereby the redox environment within the cell selectively regulates stress signalling through MEKK1 versus ASK1, and may thereby participate in the induction of apoptosis by oxidative stress.

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