CyclinD1 Protein

Cyclin D1 belongs to the highly conserved cyclin family, whose members are characterized by a dramatic periodicity in protein abundance throughout the cell cycle that functions as regulators of CDK kinases. Cyclin D1 is the regulatory subunit of a holoenzyme that phosphorylates and inactivates the RB protein and promotes progression through the G1-S phase of the cell cycle in a manner dependent on cyclin-dependent kinases, or CDKs. Cyclin D1 plays pivotal roles in the development of several human cancers, including parathyroid adenoma, breast cancer, colon cancer, lymphoma, melanoma, and prostate cancer (1). Cyclin D1 also coordinates mitochondrial function and nuclear DNA synthesis (2).