title: Rim15-dependent activation of Hsf1 and Msn2/4 transcription factors by direct phosphorylation in Saccharomyces cerevisiae.
abstract: Rim15 kinase, a downstream effector of PKA and TORC1 signaling pathways, initiates the quiescent program upon nutrient starvation via induction of genes whose expression depends on transcription factors Msn2, Msn4, and Gis1. Here, we demonstrate that Rim15 also induces expression of Hsf1 target genes upon glucose depletion by both transcriptional activation and stabilization of the transcripts. Rim15 phosphorylates Hsf1 in vitro, suggesting that Rim15 might directly activate Hsf1. In addition, Igo1 and Igo2, Rim15 substrate proteins involved in mRNA stabilization, regulate mRNA levels of Hsf1 target genes. We also show that Rim15 can phosphorylate Msn2, but not Gis1, in vitro, implying different mechanisms for the activation of these transcription factors.
authors.affiliation: School of Chemical and Biological Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-744, Republic of Korea.
authors.forename: Peter
authors.initials: P
authors.lastname: Lee
authors.forename: Myung Sup
authors.initials: MS
authors.lastname: Kim
authors.forename: Sang-Min
authors.initials: SM
authors.lastname: Paik
authors.forename: Seung-Hwan
authors.initials: SH
authors.lastname: Choi
authors.forename: Bo-Ram
authors.initials: BR
authors.lastname: Cho
authors.forename: Ji-Sook
authors.initials: JS
authors.lastname: Hahn
mesh_terms: D026905:Amino Acid Transport Systems / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D006360:Heat-Shock Proteins / Q000378:metabolism*; D056466:Histone Demethylases / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D020871:RNA Stability; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*; D015533:Transcriptional Activation; D033921:Vesicular Transport Proteins; D050888:Heat-Shock Proteins, Small
chemical_list: D026905:Amino Acid Transport Systems; D004268:DNA-Binding Proteins; D006360:Heat-Shock Proteins; D056466:Histone Demethylases; D047908:Intracellular Signaling Peptides and Proteins; D011494:Protein Kinases; D017346:Protein Serine-Threonine Kinases; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; C473804:BTN2 protein, S cerevisiae; D033921:Vesicular Transport Proteins; D050888:Heat-Shock Proteins, Small; C067168:HSF1 protein, S cerevisiae; C081935:MSN2 protein, S cerevisiae; C081937:MSN4 protein, S cerevisiae; C400297:GIS1 protein, S cerevisiae; C410736:Rim15 protein, S cerevisiae; C062391:YAK1 protein, S cerevisiae
keywords: Hsf1; Msn2/4; PKA; Phosphorylation; Rim15