Cyclin D1 (CCND1)

Cyclin D1 belongs to the family of cyclin proteins which function as the regulatory subunits of cyclin/cyclin dependent kinase (Cdk) holoenzymes that regulate entry into and progression through the cell cycle. Cyclin D1 expression is induced upon stimulation by growth factors (e.g.EGF, IGF-I/II), amino acids, hormones, and oncogenes such as Ras, Src, ErbB2, and SV40 T antigen. Cdk4 and Cdk6 can partner with Cyclin D1 in early to mid-G1 phase to phosphorylate and inactivate the cell-cycle inhibitory function of the retinoblastoma protein (pRB) in cooperation with Cyclin E/Cdk2. Cyclin D1 is also known to modulate local chromatin structure and transcription of genes involved in proliferation and differentiation through CDK-independent association with histone acetylases (e.g. CBP, P/CAF) and deacetylases.