Vembar SS, et al. (2010) J domain co-chaperone specificity defines the role of BiP during protein translocation. J Biol Chem 285(29):22484-94
Abstract: Hsp70 chaperones can potentially interact with one of several J domain-containing Hsp40 co-chaperones to regulate distinct cellular processes. However, features within Hsp70s that determine Hsp40 specificity are undefined. To investigate this question, we introduced mutations into the ER-lumenal Hsp70, BiP/Kar2p, and found that an R217A substitution in the J domain-interacting surface of BiP compromised the physical and functional interaction with Sec63p, an Hsp40 required for ER translocation. In contrast, interaction with Jem1p, an Hsp40 required for ER-associated degradation (ERAD), was unaffected. Moreover, yeast expressing R217A BiP exhibited defects in translocation, but not in ERAD. Finally, the genetic interactions of the R217A BiP mutant were found to correlate with those of known translocation mutants. Together, our results indicate that residues within Hsp70s J domain-interacting surface help confer Hsp40 specificity, in turn influencing distinct chaperone-mediated cellular activities.
|Status: Published||Type: Journal Article||PubMed ID: 20430885|
Topics addressed in this paper
Number of different genes curated to this paper: 3
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