Cyclin-dependent kinase 2 (Cdk2) is required for centrosome duplication in mammalian cells

Abstract

Centrosome duplication is indispensable for the formation of the bipolar mitotic spindle. Surprisingly, even if DNA replication or mitosis is inhibited, centrosome duplication can still occur [1] [2] [3] [4] [5]. Thus, it remains unknown how centrosome duplication is coordinated with the cell cycle. Here, we show that centrosome duplication requires cyclin-dependent kinase 2 (Cdk2) in mammalian cells. We have found that in Chinese hamster ovary (CHO) cells, whereas centrosome duplication is not inhibited by hydroxyurea (HU) treatment, which arrests the cells in S phase, it is inhibited by mimosine treatment, which arrests the cells in late G1 phase. Cdk2 activity was higher in HU-treated cells than in mimosine-treated cells. Remarkably, inhibition of the Cdk2 activity in HU-treated cells with butyrolactone I or roscovitine [6], or by expression of the Cdk inhibitor p21(Waf1/Cip1), blocked the continued centrosome duplication. Moreover, overexpression of Cdk2 reversed the inhibition of centrosome duplication by mimosine treatment. These results indicate a requirement of Cdk2 activity for centrosome duplication and therefore suggest an underlying mechanism for the coordination of centrosome duplication with the cell cycle.

RNA polymerase II transcription is required for human papillomavirus type 16 E7- and hydroxyurea-induced centriole overduplication

“…As HU-treated cells are cell cycle arrested in S phase and the a-amanitin concentrations used did not cause a cell cycle arrest (Figure 1c), this decrease of numerical centriole abnormalities is unrelated to nonspecific cell cycle effects of a-amanitin. The finding that not all cells treated with HU showed overduplication of centrioles is in line with previous reports (Balczon et al, 1995) and most likely based on the fact that a relaxation of an intrinsic block to reduplication (Wong and Stearns, 2003) occurs only in a proportion of cells (Matsumoto et al, 1999;Meraldi et al, 1999;D'Assoro et al, 2004).…”

SIAH-1 inhibits cell growth by altering the mitotic process

“…Centrosome duplication and centriole separation require cyclin-dependent kinase (Cdk2) and can be speci®cally driven by Cdk2-cyclin E complexes. In the same way, p21 Waf-1 overexpression blocks both the duplication of centrosomes and centriole separation in di erent models (Hinchcli e et al, 1999;Lacey et al, 1999;Matsumoto et al, 1999). In SIAH-1 transfected cells, centrosome anomalies in number (in multinucleated cells), in migration and in morphology were found.…”

A small molecule based on the pRb2/p130 spacer domain leads to inhibition of cdk2 activity, cell cycle arrest and tumor growth reduction in vivo

“…Although it has been described that cdk2 is not an essential gene in the mouse, (Berthet et al, 2003;Geng et al, 2003;Ortega et al, 2003;Tetsu and McCormick, 2003) an overexpression of cdk2 with associated cyclins has been shown in several tumors (Al-Aynati et al, 2004;Olofsson et al, 2004). Furthermore, cdk2 has been recently found to be required for centrosome duplication in mammalian cells (Matsumoto et al, 1999;Matsumoto and Maller, 2004) suggesting that inhibition of cdk2 activity would be an effective anticancer approach. In addition, cdk2 has rapidly emerged as a potential inhibition target by small molecule drugs that will hopefully lead to the development of effective therapies for proliferative disorders (Gibbs and Oliff, 1994;Senderowicz, 2003 We were therefore led to generate a molecular tool that provides a mechanism-based model for the inhibition of cdk2 activity.…”