A novel WISp39 protein links Hsp90 and p21 stability to the G2/M checkpoint

Transcriptional regulation of the p21Cip1 cyclin-dependent kinase inhibitor is a well-established mechanism by which the cell orchestrates a proper spatial and temporal cell cycle progression. Now, in the January 2005 issue of Molecular Cell (2005, Vol 17, 237-249), a study by Jascur et al. identifies a novel multi-protein complex that is critical in contributing to a p53-dependent G2 cell cycle checkpoint. The authors demonstrate the significance of stabilizing the p21 protein in the context of this complex.