Threonine 22 phosphorylation attenuates Hsp90 interaction with cochaperones and affects its chaperone activity.
Mol Cell
; 41(6): 672-81, 2011 Mar 18.
Article
in En
| MEDLINE
| ID: mdl-21419342
ABSTRACT
Heat shock protein 90 (Hsp90) is an essential molecular chaperone whose activity is regulated not only by cochaperones but also by distinct posttranslational modifications. We report here that casein kinase 2 phosphorylates a conserved threonine residue (T22) in α helix-1 of the yeast Hsp90 N-domain both in vitro and in vivo. This α helix participates in a hydrophobic interaction with the catalytic loop in Hsp90's middle domain, helping to stabilize the chaperone's ATPase-competent state. Phosphomimetic mutation of this residue alters Hsp90 ATPase activity and chaperone function and impacts interaction with the cochaperones Aha1 and Cdc37. Overexpression of Aha1 stimulates the ATPase activity, restores cochaperone interactions, and compensates for the functional defects of these Hsp90 mutants.
Full text:
1
Database:
MEDLINE
Main subject:
Threonine
/
Fungal Proteins
/
Molecular Chaperones
/
HSP90 Heat-Shock Proteins
Limits:
Humans
Language:
En
Journal:
Mol Cell
Journal subject:
BIOLOGIA MOLECULAR
Year:
2011
Type:
Article
Affiliation country:
United States