title: Yeast Pdr13p and Zuo1p molecular chaperones are new functional Hsp70 and Hsp40 partners.
abstract: The deletion of the TOM1 gene encoding a putative ubiquitin ligase causes a temperature sensitive cellular growth in Saccharomyces cerevisiae. The arrested cells exhibit pleiotropic defects in nuclear division, maintenance of nuclear structure and heat stress responses. We previously identified a zuo1 mutation as an extragenic suppressor of the tom1 mutant. ZUO1 encodes a DnaJ-related Hsp40. Here we show that a recessive cold sensitive mutation in PDR13 coding for an Hsp70 suppressed the tom1 mutation. The pdr13 deletion mutant was sensitive to high osmolarity, just like the zuo1 deletion mutant. A zuo1 pdr13 double deletion mutant did not show additive phenotypes. Furthermore, a tagged-Zuo1p was co-immunoprecipitated with a tagged-Pdr13p. Taken together, we propose that Pdr13p and Zuo1p are a new pair of Hsp70:Hsp40 molecular chaperones. In addition, Pdr13p co-sedimented with translating ribosomes and this association was independent of the presence of Zuo1p.
authors.affiliation: Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Tokyo 113-0033, Bunkyo-ku, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Michimoto
authors.forename: T
authors.initials: T
authors.lastname: Aoki
authors.forename: A
authors.initials: A
authors.lastname: Toh-e
authors.forename: Y
authors.initials: Y
authors.lastname: Kikuchi
mesh_terms: D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D018628:Gene Dosage; D050956:HSP40 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D018832:Molecular Chaperones / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D010641:Phenotype; D011485:Protein Binding; D012270:Ribosomes / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D029702:Schizosaccharomyces pombe Proteins; D013489:Suppression, Genetic; D044767:Ubiquitin-Protein Ligases
chemical_list: D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D050956:HSP40 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D018398:Homeodomain Proteins; D018832:Molecular Chaperones; C095192:SSB1 protein, S cerevisiae; C101143:SSB2 protein, S pombe; D029701:Saccharomyces cerevisiae Proteins; D029702:Schizosaccharomyces pombe Proteins; C077019:ZUO1 protein, S cerevisiae; C115246:TOM1 protein, S cerevisiae; D044767:Ubiquitin-Protein Ligases