title: Physical interaction between the MAPK Slt2 of the PKC1-MAPK pathway and Grx3/Grx4 glutaredoxins is required for the oxidative stress response in budding yeast.
abstract: This study demonstrates that both monothiol glutaredoxins Grx3 and Grx4 physically interact with the MAPK Slt2 forming a complex involved in the cellular response to oxidative stress. The simultaneous absence of Grx3 and Grx4 provokes a serious impairment in cell viability, Slt2 activation and Rlm1 transcription in response to oxidative stress. Both in vivo and in vitro results clearly show that Slt2 can independently bind either Grx3 or Grx4 proteins. Our results suggest that Slt2 form iron/sulphur bridged clusters with Grx3 and Grx4. For the assembly of this complex, cysteines of the active site of each Grx3/4 glutaredoxins, glutathione and specific cysteine residues from Slt2 provide the ligands. One of the ligands of Slt2 is required for its dimerisation upon oxidative treatment and iron repletion. These interactions are relevant for the oxidative response, given that mutants in the cysteine ligands identified in the complex show a severe impairment of both cell viability and Slt2 phosphorylation upon oxidative stress. Grx4 is the relevant glutaredoxin that regulates Slt2 phosphorylation under oxidative conditions precluding cell survival. Our studies contribute to extend the functions of both monothiol glutaredoxins to the regulation of a MAPK in the context of the oxidative stress response.
authors.affiliation: Department of Basic Medical Sciences, IRB-Lleida. University of Lleida, Av. Alcalde Rovira Roure no 80, 25198 Lleida, Spain.
authors.forename: Nuria
authors.initials: N
authors.lastname: Pujol-Carrion
authors.affiliation: Department of Basic Medical Sciences, IRB-Lleida. University of Lleida, Av. Alcalde Rovira Roure no 80, 25198 Lleida, Spain. Electronic address: madelatorre@cmb.udl.cat.
authors.forename: Maria Angeles de la
authors.initials: MA
authors.lastname: Torre-Ruiz
mesh_terms: D000595:Amino Acid Sequence; D054477:Glutaredoxins / Q000737:chemistry / Q000378:metabolism*; D020935:MAP Kinase Signaling System; D020928:Mitogen-Activated Protein Kinases / Q000737:chemistry / Q000378:metabolism*; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D010088:Oxidoreductases / Q000737:chemistry / Q000378:metabolism*; D010766:Phosphorylation; D054730:Protein Interaction Domains and Motifs; D055503:Protein Multimerization; D011499:Protein Processing, Post-Translational; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000378:metabolism*
chemical_list: D054477:Glutaredoxins; C516012:Grx4 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C545181:Grx3 protein, S cerevisiae; D010088:Oxidoreductases; D020928:Mitogen-Activated Protein Kinases; C072724:SLT2 protein, S cerevisiae
keywords: Budding yeast; Cell survival; Glutaredoxins; Iron; MAPK; Oxidative stress; PKC1 pathway; Signalling