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The molecular chaperone Hsp90 plays a role in the assembly and maintenance of the 26S proteasome
Author(s) -
Imai Jun,
Maruya Mikako,
Yashiroda Hideki,
Yahara Ichiro,
Tanaka Keiji
Publication year - 2003
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1093/emboj/cdg349
Subject(s) - hsp90 , proteasome , biology , microbiology and biotechnology , geldanamycin , chaperone (clinical) , protein subunit , saccharomyces cerevisiae , biochemistry , heat shock protein , yeast , gene , medicine , pathology
Hsp90 has a diverse array of cellular roles including protein folding, stress response and signal transduction. Herein we report a novel function for Hsp90 in the ATP‐dependent assembly of the 26S proteasome. Functional loss of Hsp90 using a temperature‐sensitive mutant in yeast caused dissociation of the 26S proteasome. Conversely, these dissociated constituents reassembled in Hsp90‐dependent fashion both in vivo and in vitro ; the process required ATP‐hydrolysis and was suppressed by the Hsp90 inhibitor geldanamycin. We also found genetic interactions between Hsp90 and several proteasomal Rpn ( R egulatory p article n on‐ATPase subunit) genes, emphasizing the importance of Hsp90 to the integrity of the 26S proteasome. Our results indicate that Hsp90 interacts with the 26S proteasome and plays a principal role in the assembly and maintenance of the 26S proteasome.