Regulatory component of the cyclin D2-CDK4 (DC) complex that phosphorylates and inhibits members of the retinoblastoma (RB) protein family including RB1 and regulates the cell-cycle during G(1)/S transition (, ). Phosphorylation of RB1 allows dissociation of the transcription factor E2F from the RB/E2F complex and the subsequent transcription of E2F target genes which are responsible for the progression through the G(1) phase (, ). Hypophosphorylates RB1 in early G(1) phase (, ). Cyclin D-CDK4 complexes are major integrators of various mitogenenic and antimitogenic signals (, ).
Subcellular locations: Nucleus, Cytoplasm, Nucleus membrane
Cyclin D-CDK4 complexes accumulate at the nuclear membrane and are then translocated into the nucleus through interaction with KIP/CIP family members.
Subcellular locations: Cytoplasm