Regulation of Protein Kinases Associated with Cyclin A and Cyclin B and Their Effect on Microtubule Dynamics and Nucleation in Xenopus Egg Extracts

Excerpt

In all eukaryotic cells, progression through the cell division cycle involves the temporal regulation of a major protein kinase, the catalytic subunit of which is encoded by the cdc2/CDC28 genes in yeast or their homologs in higher eukaryotes (Dorée et al. 1989; Draetta 1990; Nurse 1990). The periodic activation of the cdc2 catalytic subunit involves its association with at least one other class of molecules, the cyclins (Hunt 1989; Murray and Kirschner 1989b). Both in fission yeast and in budding yeast, the cdc2/CDC28 gene products are required at the G₁/S and G₂/M transitions (Lee and Nurse 1988; Russell et al. 1989; Wittenberg and Reed 1989), and growing evidence suggests that cdc2 kinase activity, function, and subcellular localization are regulated by related, but different, cyclin molecules expressed in G₁ (G₁ cyclins) or during the G₂/M transition (mitotic cyclins) (Hadwiger et al. 1989; Nasmyth 1990; Wittenberg et al. 1990; Ghiara et al....