| First Author | Stepanova L | Year | 1996 |
| Journal | Genes Dev | Volume | 10 |
| Issue | 12 | Pages | 1491-502 |
| PubMed ID | 8666233 | Mgi Jnum | J:39400 |
| Mgi Id | MGI:86865 | Doi | 10.1101/gad.10.12.1491 |
| Citation | Stepanova L, et al. (1996) Mammalian p50Cdc37 is a protein kinase-targeting subunit of Hsp90 that binds and stabilizes Cdk4. Genes Dev 10(12):1491-502 |
| abstractText | CDC37, an essential gene in Saccharomyces cerevisiae, interacts genetically with multiple protein kinases and is required for production of Cdc28p/cyclin complexes through an unknown mechanism. We have identified mammalian p50Cdc37 as a protein kinase-targeting subunit of the molecular chaperone Hsp90. Previously, p50 was observed in complexes with pp60v-src and Raf-1, but its identity and function have remained elusive. In mouse fibroblasts, a primary target of Cdc37 is Cdk4. This kinase is activated by D-type cyclins and functions in passage through G1. In insect cells, Cdc37 is sufficient to target Hsp90 to Cdk4 and both in vitro and in vivo, Cdc37/Hsp90 associates preferentially with the fraction of Cdk4 not bound to D-type cyclins. Cdc37 is coexpressed with cyclin Dl in cells undergoing programmed proliferation in vivo, consistent with a positive role in cell cycle progression. Pharmacological inactivation of Cdc37/Hsp90 function decreases the half-life of newly synthesized Cdk4, indicating a role for Cdc37/Hsp90 in Cdk4 stabilization. This study suggests a general role for p50Cdc37 in signaling pathways dependent on intrinsically unstable protein kinases and reveals a previously unrecognized chaperone-dependent step in the production of Cdk4/cyclin D complexes. |
