Cyclin-dependent kinases (CDKs) are the families of protein kinases first discovered for their role in regulating the cell cycle. They are also involved in regulating transcription, mRNA processing, and the differentiation of nerve cells. They are present in all known eukaryotes, and their regulatory function in the cell cycle has been evolutionarily conserved. In fact, yeast cells can proliferate normally when their CDK gene has been replaced with the homologous human gene. CDKs are relatively small proteins, with molecular weights ranging from 34 to 40 kDa, and contain little more than the kinase domain. By definition, a CDK binds a regulatory protein called a cyclin. Without cyclin, CDK has little kinase activity; only the cyclin-CDK complex is an active kinase but its activity can be typically further modulated by phosphorylation and other binding proteins, like p27. CDKs phosphorylate their substrates on serines and threonines, so they are serine-threonine kinases. The consensus sequence for the phosphorylation site in the amino acid sequence of a CDK substrate is [S/T*]PX[K/R], where S/T* is the phosphorylated serine or threonine, P is proline, X is any amino acid, K is lysine, and R is arginine.
Cyclin-dependent kinase 4 also known as cell division protein kinase 4 is an enzyme that in humans is encoded by the CDK4 gene. CDK4 is a member of the cyclin-dependent kinase family.
Cell division protein kinase 6 (CDK6) is an enzyme encoded by the CDK6 gene. It is regulated by cyclins, more specifically by Cyclin D proteins and Cyclin-dependent kinase inhibitor proteins. The protein encoded by this gene is a member of the cyclin-dependent kinase, (CDK) family, which includes CDK4. CDK family members are highly similar to the gene products of Saccharomyces cerevisiae cdc28, and Schizosaccharomyces pombe cdc2, and are known to be important regulators of cell cycle progression in the point of regulation named R or restriction point.
Cyclin G-associated kinase (GAK) is a serine/threonine kinase that in humans is encoded by the GAK gene.
Cyclin-dependent kinase 1 also known as CDK1 or cell division cycle protein 2 homolog is a highly conserved protein that functions as a serine/threonine protein kinase, and is a key player in cell cycle regulation. It has been highly studied in the budding yeast S. cerevisiae, and the fission yeast S. pombe, where it is encoded by genes cdc28 and cdc2, respectively. With its cyclin partners, Cdk1 forms complexes that phosphorylate a variety of target substrates ; phosphorylation of these proteins leads to cell cycle progression.
Cyclin-dependent kinase 7, or cell division protein kinase 7, is an enzyme that in humans is encoded by the CDK7 gene.
Cyclin-A2 is a protein that in humans is encoded by the CCNA2 gene. It is one of the two types of cyclin A: cyclin A1 is expressed during meiosis and embryogenesis while cyclin A2 is expressed in the mitotic division of somatic cells.
In enzymology, a tau-protein kinase is an enzyme that catalyzes the chemical reaction
Cyclin-dependent kinase 5 activator 1 is an enzyme that in humans is encoded by the CDK5R1 gene.
Ran-binding protein 9 is a protein that in humans is encoded by the RANBP9 gene.
Cell division cycle 7-related protein kinase is an enzyme that in humans is encoded by the CDC7 gene. The Cdc7 kinase is involved in regulation of the cell cycle at the point of chromosomal DNA replication. The gene CDC7 appears to be conserved throughout eukaryotic evolution; this means that most eukaryotic cells have the Cdc7 kinase protein.
Serine/threonine protein kinase NLK is an enzyme that in humans is encoded by the NLK gene. Its name is an abbreviation for Nemo-Like Kinase, Nemo (nmo) being the Drosophila ortholog of the mammalian NLK gene. This enzyme is a member of the Mitogen-activated protein kinase (MAPK) family, although not explicitly designated as such. It is a highly divergent, atypical member of the MAPK group, lacking most features so characteristic of most mitogen-activated protein kinases. Its activation mechanism and downstream targets are still not well characterized.
Cyclin dependent kinase 13 is an enzyme that in humans is encoded by the CDK13 gene.
Cell division protein kinase 3 is an enzyme that in humans is encoded by the CDK3 gene.
Cyclin-dependent kinase inhibitor 3 is an enzyme that in humans is encoded by the CDKN3 gene.
Serine/threonine-protein kinase VRK1 is an enzyme that in humans is encoded by the VRK1 gene.
Serine/threonine-protein kinase PCTAIRE-2 is an enzyme that in humans is encoded by the PCTK2 gene.
Cyclin-dependent kinase 5 is a protein, and more specifically an enzyme, that is encoded by the Cdk5 gene. It was discovered 15 years ago, and it is saliently expressed in post-mitotic central nervous system neurons (CNS).
Cyclin-dependent kinase-like 2 is an enzyme that in humans is encoded by the CDKL2 gene.
Cdk5 and Abl enzyme substrate 2 is a protein that in humans is encoded by the CABLES2 gene.
