A cyclin associated with the CDK-activating kinase MO15

• Published in: Nature (London) Vol. 371; no. 6494; pp. 254 - 257
• Main Authors: Mäkelä, Tomi P, Tassan, Jean-Pierre, Nigg, Erich A, Frutiger, Séverine, Hughes, Graham J, Weinberg, Robert A
• Format: Journal Article
• Language: English
• Published: London Nature Publishing 15.09.1994; Nature Publishing Group
• Subjects: Amino Acid Sequence; Animals; Base Sequence; Biochemistry; Biological and medical sciences; Cdk-activating kinase; cDNA; Cell Line; Cell physiology; Cyclin H; Cyclin-Dependent Kinases; Cyclins - metabolism; DNA; Fundamental and applied biological sciences. Psychology; genes; HeLa Cells; Humans; interaction; man; MO15 protein; Molecular and cellular biology; Molecular Sequence Data; nucleotide sequence; prediction; protein kinase; Protein-Serine-Threonine Kinases - metabolism; Proteins; Recombinant Proteins - metabolism; Saccharomyces cerevisiae; Signal transduction; Transfection; Xenopus; Yeasts; Human; Nucleotide sequence; Enzyme; Transferases; Cyclin; In vitro; Signal transduction; Enzymatic activity; Complementary DNA; Molecular association; Nuclear protein; Aminoacid sequence; Structural analysis
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/371254a0

The eukaryotic cell cycle is regulated by the sequential activation of cyclin-dependent kinases (CDKs). CDK activation is dependent on cyclin binding and phosphorylation of a conserved threonine (T161 in Cdc2) mediated by the CDK-activating kinase CAK. A CDK-related kinase, MO15 (ref. 10), has been identified as the catalytic subunit of CAK (refs 11-13). Here we use a yeast two-hybrid screen to show that a new human cyclin (cyclin H) is a MO15-associated protein. Cyclin H is a major MO15 partner in vivo and enhances the kinase activity of MO15 towards Cdk2/cyclin A. These findings demonstrate that a cyclin/kinase complex can function as a regulator of other cyclin/kinase complexes, and suggest that cyclin/kinase cascades may exist.