Hsp90 phosphorylation is linked to its chaperoning function. Assembly of the reovirus cell attachment protein.
Studies on Hsp90 have mainly focused on its involvement in the activation of several families of protein kinases and of steroid hormone receptors. Little is known regarding the role of Hsp90 in the folding of nascent proteins. We previously reported that Hsp90 plays an active role in the posttranslational assembly of the C-terminal globular head of the reovirus attachment protein final sigma1. We show here that Hsp90 becomes phosphorylated in this process. However, only the unphosphorylated form of Hsp90 is complexed with final sigma1, suggesting that Hsp90 phosphorylation is coupled to the release of the chaperone from the target protein. Geldanamycin, which blocks final sigma1 maturation by preventing the release of Hsp90 from final sigma1, also inhibits Hsp90 phosphorylation. Taken together, these results demonstrate that Hsp90 phosphorylation is linked to its chaperoning function.
Zhao
Y G
YG
Cancer Biology Research Group and the Department of Microbiology and Infectious Diseases, Faculty of Medicine, University of Calgary, Calgary, Alberta T2N 4N1, Canada.
Gilmore
R
R
Leone
G
G
Coffey
M C
MC
Weber
B
B
Lee
P W
PW
D000818:Animals; D016227:Benzoquinones; D036022:Capsid Proteins; D002417:Cattle; D018841:HSP90 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D006388:Hemagglutinins / Q000235:genetics / Q000378:metabolism; D047029:Lactams, Macrocyclic; D010750:Phosphoproteins / Q000378:metabolism*; D010766:Phosphorylation; D014176:Protein Biosynthesis; D017510:Protein Folding; D011499:Protein Processing, Post-Translational; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors; D011809:Quinones / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics; D011817:Rabbits; D011994:Recombinant Proteins / Q000378:metabolism; D012087:Reoviridae / Q000502:physiology*; D012156:Reticulocytes / Q000378:metabolism; D014158:Transcription, Genetic; D014764:Viral Proteins / Q000235:genetics* / Q000378:metabolism
D016227:Benzoquinones; D036022:Capsid Proteins; D018841:HSP90 Heat-Shock Proteins; D006388:Hemagglutinins; D047029:Lactams, Macrocyclic; D010750:Phosphoproteins; D011809:Quinones; D012333:RNA, Messenger; D011994:Recombinant Proteins; D014764:Viral Proteins; C031728:sigma 1 protein, reovirus; D011505:Protein-Tyrosine Kinases; C001277:geldanamycin