Zuotin, a ribosome-associated DnaJ molecular chaperone.
Correct folding of newly synthesized polypeptides is thought to be facilitated by Hsp70 molecular chaperones in conjunction with DnaJ cohort proteins. In Saccharomyces cerevisiae, SSB proteins are ribosome-associated Hsp70s which interact with the newly synthesized nascent polypeptide chain. Here we report that the phenotypes of an S.cerevisiae strain lacking the DnaJ-related protein Zuotin (Zuo1) are very similar to those of a strain lacking Ssb, including sensitivities to low temperatures, certain protein synthesis inhibitors and high osmolarity. Zuo1, which has been shown previously to be a nucleic acid-binding protein, is also a ribosome-associated protein localized predominantly in the cytosol. Analysis of zuo1 deletion and truncation mutants revealed a positive correlation between the ribosome association of Zuo1 and its ability to bind RNA. We propose that Zuo1 binds to ribosomes, in part, by interaction with ribosomal RNA and that Zuo1 functions with Ssb as a chaperone on the ribosome.
Department of Biomolecular Chemistry, University of Wisconsin, 1300 University Avenue, Madison, WI 53706, USA.
W
W
Yan
B
B
Schilke
C
C
Pfund
W
W
Walter
S
S
Kim
E A
EA
Craig
D003600:Cytosol / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005656:Fungal Proteins / Q000378:metabolism*; D050956:HSP40 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D006360:Heat-Shock Proteins / Q000378:metabolism*; D018832:Molecular Chaperones; D010641:Phenotype; D012270:Ribosomes / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins
D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D050956:HSP40 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D018832:Molecular Chaperones; C095192:SSB1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C077019:ZUO1 protein, S cerevisiae