title: CK2-dependent inhibitory phosphorylation is relieved by Ppt1 phosphatase for the ethanol stress-specific activation of Hsf1 in Saccharomyces cerevisiae.
abstract: Ethanol, the major fermentation product of Saccharomyces cerevisiae, has long been known as an inducer of heat shock response, but the underlying mechanisms by which ethanol activates heat shock transcription factor (HSF) are not well understood. We demonstrate that CK2-dependent phosphorylation on S608 is an ethanol stress-specific repression mechanism of Hsf1, which does not affect the basal or heat-induced activity of Hsf1. This repression is relieved by dephosphorylation by Ppt1 which directly interacts with Hsf1 via its tetratricopeptide repeat (TPR) domain. In response to ethanol stress, PPT1 deletion and CK2 overexpression exert synergistic inhibitory effects on Hsf1 activation, whereas Hsf1(S608A) mutant shows enhanced activation. Therefore, regulation of the Hsf1 S608 phosphorylation status by reciprocal actions of CK2 and Ppt1 might play an important role to determine Hsf1 sensitivity towards ethanol stress.
authors.affiliation: Interdisciplinary Program for Bioengineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 151-744, Korea.
authors.forename: Bo-Ram
authors.initials: BR
authors.lastname: Cho
authors.forename: Peter
authors.initials: P
authors.lastname: Lee
authors.forename: Ji-Sook
authors.initials: JS
authors.lastname: Hahn
mesh_terms: D015153:Blotting, Western; D047390:Casein Kinase II / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000431:Ethanol / Q000378:metabolism*; D006360:Heat-Shock Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010749:Phosphoprotein Phosphatases / Q000378:metabolism*; D010766:Phosphorylation; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D013312:Stress, Physiological; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D004268:DNA-Binding Proteins; C067168:HSF1 protein, S cerevisiae; D006360:Heat-Shock Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D000431:Ethanol; D047390:Casein Kinase II; C089640:PPT1 protein, S cerevisiae; D010749:Phosphoprotein Phosphatases