Recombinant human CDK4 + CCND3 protein (ab85646)

CDK4 is a member of the Ser/Thr protein kinase family. It is highly similar to the gene products of S. cerevisiae cdc28, and S. pombe cdc2. CDK4 is a catalytic subunit of the protein kinase complex that is important for cell cycle G1 phase progression. The activity of this kinase is restricted to the G1/S phase, which is controlled by the regulatory subunits D type cyclins and CDK inhibitor p16(INK4a). CDK4 was shown to be responsible for the phosphorylation of retinoblastoma gene product (Rb). Mutations in this gene as well as its related proteins including D type cyclins, p16(INK4a) and Rb were all found to be associated with tumorigenesis of a variety of cancers. CCND3 (Cyclin D3) belongs to the highly conserved cyclin family, whose members are characterized by a dramatic periodicity in protein abundance through the cell cycle. Cyclins function as regulators of CDK kinases. Different cyclins exhibit distinct expression and degradation patterns which contribute to the temporal coordination of each mitotic event. CCND3 forms a complex with and functions as a regulatory subunit of CDK4 or CDK6, whose activtiy is required for cell cycle G1/S transition. It has been shown to interact with and be involved in the phosphorylation of tumor suppressor protein Rb.

CCND3: Cytoplasm. Nucleus.