The double edge of the HSP90-CDC37 chaperone machinery: opposing determinants of kinase stability and activity.
The molecular chaperone HSP90, in concert with the co-chaperone CDC37, facilitates the maturation and modulates the activity of a variety of protein kinases. In this article, Gaude and colleagues described the dual activities of the HSP90-CDC37 chaperone machinery in maintaining the stability while inhibiting the activity of LKB1 kinase. LKB1 in complex with HSP90-CDC37 has a longer half-life but is incapable of autophosphorylation, and its kinase activity is increased upon HSP90 inhibition. Dissociation of HSP90 from LKB1 results in its interaction with HSP/HSC70. HSP/HSC70 recruits the ubiquitin ligase CHIP, which ubiquitinates LKB1, leading to its proteasome-mediated degradation. These data emphasize the versatile roles of molecular chaperones associated with LKB1 and warrant future studies to characterize the clinical relevance of these observations.
Urologic Oncology Branch, National Cancer Institute, Bethesda, MD, USA.
Wanping
W
Xu
Len
L
Neckers