Open AccessProteome-wide identification of HSP70/HSC70 chaperone clients in human cells
Author(s) -
Seung Woo Ryu,
Rose Stewart,
D Chase Pectol,
Nicolette A. Ender,
Oshadi Wimalarathne,
Ji-Hoon Lee,
Carlos P. Zanini,
Antony Harvey,
Jon M. Huibregtse,
Peter Müeller,
Tanya T. Paull
Publication year - 2020
Publication title -
plos biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.127
H-Index - 271
eISSN - 1545-7885
pISSN - 1544-9173
DOI - 10.1371/journal.pbio.3000606
Subject(s) - biology , hsp70 , interactome , chaperone (clinical) , proteome , heat shock protein , microbiology and biotechnology , protein folding , sod1 , ubiquitin , proteostasis , protein aggregation , protein subunit , heat shock , biochemistry , superoxide dismutase , enzyme , medicine , pathology , gene
The 70 kDa heat shock protein (HSP70) family of chaperones are the front line of protection from stress-induced misfolding and aggregation of polypeptides in most organisms and are responsible for promoting the stability, folding, and degradation of clients to maintain cellular protein homeostasis. Here, we demonstrate quantitative identification of HSP70 and 71 kDa heat shock cognate (HSC70) clients using a ubiquitin-mediated proximity tagging strategy and show that, despite their high degree of similarity, these enzymes have largely nonoverlapping specificities. Both proteins show a preference for association with newly synthesized polypeptides, but each responds differently to changes in the stoichiometry of proteins in obligate multi-subunit complexes. In addition, expression of an amyotrophic lateral sclerosis (ALS)-associated superoxide dismutase 1 (SOD1) mutant protein induces changes in HSP70 and HSC70 client association and aggregation toward polypeptides with predicted disorder, indicating that there are global effects from a single misfolded protein that extend to many clients within chaperone networks. Together these findings show that the ubiquitin-activated interaction trap (UBAIT) fusion system can efficiently isolate the complex interactome of HSP chaperone family proteins under normal and stress conditions.