Cyclin-dependent kinase 6–cyclin D3 complex (CDK6–cyclin D3)

The Cyclin-dependent kinase 6–cyclin D3 complex is a critical driver of cell proliferation, acting at the G1/S checkpoint of the cell cycle. CDK6 is a serine/threonine-protein kinase whose activation requires binding to cyclin D3, forming a functional complex that phosphorylates substrates such as retinoblastoma protein (pRB/RB1) to promote cell cycle progression. In cancer cells, particularly leukemia and some solid tumors, elevated complex activity supports uncontrolled growth and survival, in part by redirecting glucose metabolism to produce anti-oxidants and shield cells from oxidative damage. Inhibition of this complex by small molecules (e.g., palbociclib) is a validated therapeutic strategy that induces cell cycle arrest and apoptosis. Monitoring levels of cyclin D3–CDK6 can guide patient selection and treatment efficacy, while safety concerns largely relate to adverse effects on normal proliferating cells

Other names

CDK6/cyclin D3CDK6–D3CDK6:cyclin D3cyclin D3–CDK6 complex

Inhibition of kinase activity: Drugs bind to CDK6 (and often CDK4) ATP-binding sites, blocking phosphorylation activity and causing cell cycle arrest in G1 phase Indirect induction of apoptosis via disruption of metabolic pathways