a protein kinase of the CDK family that is important for cell cycle G1 phase progression. Its activity is restricted to the G1-S phase. Controlled by the regulatory subunits D-type cyclins and CDK inhibitor p16(INK4a). Phosphorylates the retinoblastoma gene product (Rb). Point mutations found in somatic and familial melanoma. Amplified in sarcomas, glioma and lymphoma. Amplified, methylated or deleted in head and neck squamous cell carcinoma. Overexpression drives epithelial tumors in mice. Disruption makes mice resistant to cancer. Inhibitor: PD332991. Note: This description may include information from UniProtKB.
Protein type: Kinase, protein; EC 188.8.131.52; Protein kinase, Ser/Thr (non-receptor); Protein kinase, CMGC; CMGC group; CDK family; CDK4 subfamily; CDK/CDK4 subfamily
Molecular Function: protein binding; cyclin-dependent protein kinase activity; ATP binding
Biological Process: response to drug; positive regulation of fibroblast proliferation; cell division; regulation of gene expression; regulation of cell cycle; positive regulation of cell proliferation; mitotic cell cycle; S phase of mitotic cell cycle; G1 phase of mitotic cell cycle; signal transduction; protein amino acid phosphorylation; G1/S transition of mitotic cell cycle
SS: The number of records in which this modification site was determined using site-specific methods. SS methods include amino acid sequencing, site-directed mutagenesis, modification site-specific antibodies, specific MS strategies, etc.