Cell Cycle

"Pin"ning Down DNA Replication Checkpoints

Science's STKE  07 Mar 2000:
Vol. 2000, Issue 22, pp. tw5
DOI: 10.1126/stke.2000.22.tw5

The Pin1 protein is a peptidyl-prolyl isomerase that is thought to function in control of the cell division cycle. However, its precise role in control of cell proliferation has been unclear. Winkler et al. examined Pin1 function in Xenopus egg extracts. Extracts depleted of Pin1 entered mitosis more quickly than did controls. Normally, the presence of unreplicated DNA prevents progression of the cell cycle from G2 to M phase. However, extracts lacking Pin1 progressed into mitosis even when DNA replication was inhibited. Thus, although the mechanisms by which Pin1 acts remain obscure, it appears that Pin1 is required for proper function of the DNA replication checkpoint in Xenopus eggs.

Winkler, K.E., Swenson, K.I., Kornbluth, S., and Means, A.R. (2000) Requirement of the prolyl isomerase Pin1 for the replication checkpoint. Science 287: 1644-1647. [Abstract] [Full Text]