Prior to cell division, normal adherent cells adopt a round morphology that is associated with a loss of actin stress fibres and disassembly of focal adhesions. In this study, we investigate the mitotic phosphorylation of the recently described paxillin and actin-binding focal-adhesion protein actopaxin [Nikolopoulos and Turner (2000) J. Cell Biol. 151, 1435-1448]. Actopaxin is comprised of an ...

Yeasts p13suc1/p18CKS and their human homologues, p9CKShs1/p9CKShs2, strongly interact with p34cdc2 and p34cdk2. While attempting to purify the starfish oocyte p13suc1 homologue, we discovered a 15-kDa protein cross-reactive with anti-p9CKShs2/anti-p13suc1 antibodies. p15cdk-BP-Sepharose binds an anti-PSTAIRE cross-reactive protein of 33 kDa when loaded with starfish oocyte extracts. The p15cdk...

Abbreviat ions : adrenocorticotrophic hormone, (ACTH); casein kinase I, (CKI); Cdc2-like kinase, (Clk); Concanavalin A, (ConA); cystic fibrosis transmembrane conductance regulator, (CFTR); epidermal growth factor, (EGF); exonic splicing enhancer, (ESE); exonic splicing silencer, (ESS); fibroblast growth factor, (FGF); heterogeneous nuclear protein, (hnRNP); interferon, (IFN); interleukin, (IL);...

The transcription inhibitor tetra-O-methyl nordihydroguaiaretic acid (M4N) was found to arrest the proliferation of C3, C33a, CEM-T4, and TC-1 cells in culture at the G2 stage of the cell cycle. Investigation into the mechanism of arrest revealed that M4N reduces mRNA levels and subsequent protein production of the cyclin-dependent kinase CDC2, resulting in the inactivation of the CDC2/cyclin B...

Cyclin-dependent kinases (cdk) play an essential role in the intracellular control of the cell division cycle (cdc). These kinases and their regulators are frequently deregulated in human tumours. Enzymatic screening has recently led to the discovery of specific inhibitors of cyclin-dependent kinases, such as butyrolactone I, flavopiridol and the purine olomoucine. Among a series of C2, N6, N9-...

During the cell cycle, a checkpoint prevents the initiation of mitosis until S-phase is completed. The molecular mechanism may involve the RCC1 protein, which catalyses guanine nucleotide exchange on the Ras-related nuclear protein, Ran (or TC4). Genetic studies have suggested that RCC1 may be involved in sensing the replication state of DNA and controlling the activation of Cdc2/cyclin B prote...

We describe a refined homology model of a CDK1/cyclin B complex that was previously used for the structure-based optimization of the Paullone class of inhibitors. The preliminary model was formed from the homologous regions of the deposited CDK2/cyclin A crystal structure. Further refinement of the CDK1/cyclin B complex was accomplished using molecular mechanics and hydropathic analysis with a ...

The CDK (cyclin-dependent kinase) family of enzymes is required for the G(1)-to-S-phase and G(2)-to-M-phase transitions during the cell-division cycle of eukaryotes. We have shown previously that the protein kinase CKII catalyses the phosphorylation of Ser-39 in Cdc2 during the G(1) phase of the HeLa cell-division cycle [Russo, Vandenberg, Yu, Bae, Franza and Marshak (1992) J. Biol. Chem. 267, ...

PLK (STPK13) encodes a murine protein kinase closely related to those encoded by the Drosophila melanogaster polo gene and the Saccharomyces cerevisiae CDC5 gene, which are required for normal mitotic and meiotic divisions. Affinity-purified antibody generated against the C-terminal 13 amino acids of Plk specifically recognizes a single polypeptide of 66 kDa in MELC, NIH 3T3, and HeLa cellular ...