Checkpoint kinase 1 (Chk1) is required for mitotic progression through negative regulation of polo-like kinase 1 (Plk1).

ABSTRACT: Although the essential function of checkpoint kinase 1 (Chk1) in DNA damage response has been well established, the role of Chk1 in normal cell cycle progression is unclear. By using RNAi to specifically deplete Chk1, we determined loss-of-function phenotypes in HeLa cells. A vector-based RNAi approach showed that Chk1 is required for normal cell proliferation and survival, inasmuch as a dramatic cell-cycle arrest at G(2)/M phase and massive apoptosis were observed in Chk1-deficient cells. Coupling of siRNA with cell synchronization further revealed that Chk1 depletion leads to metaphase block, as indicated by various mitotic markers. Neither bipolar spindle formation nor centrosome functions were affected by Chk1 depletion; however, the depleted cells exhibited chromosome misalignment dur

SUBMITTER: Tang J 

PROVIDER: S-EPMC1567681 | biostudies-literature | 2006 Aug

REPOSITORIES: biostudies-literature