Single methyl group determines prion propagation and protein degradation activities of yeast heat shock protein (Hsp)-70 chaperones Ssa1p and Ssa2p.

ABSTRACT: Organisms encode multiple homologous heat shock protein (Hsp)-70s, which are essential protein chaperones that play the major role in cellular protein "quality control." Although Hsp70s are functionally redundant and highly homologous, many possess distinct functions. A regulatory motif underlying such distinctions, however, is unknown. The 98% identical cytoplasmic Hsp70s Ssa1p and Ssa2p function differently with regard to propagation of yeast [URE3] prions and in the vacuolar-mediated degradation of gluconeogenesis enzymes, such as FBPase. Here, we show that the Hsp70 nucleotide binding domain (NBD) regulates these functional specificities. We find little difference in ATPase, protein refolding, and amyloid inhibiting activities of purified Ssa1p and Ssa2p, but show that interchanging NB

SUBMITTER: Sharma D 

PROVIDER: S-EPMC3158190 | biostudies-literature | 2011 Aug

REPOSITORIES: biostudies-literature