Cyclin D3 (CCND3)

Cyclin D3 is a regulatory protein encoded by the *CCND3* gene and is a member of the highly conserved cyclin family, which controls temporal progression through the cell cycle by periodic changes in abundance[1][3][8]. Cyclin D3 forms complexes with CDK4 or CDK6, acting as a necessary regulatory subunit for kinase activation and enabling transition from G1 to S phase by phosphorylating and inhibiting retinoblastoma (RB) protein family members, notably RB1[1][8]. It is implicated in regulation of cell proliferation and signal transduction, particularly in tissues with high mitotic activity[1][8]. Cyclin D3 is clinically significant, with its deregulation or mutation implicated in various cancers such as breast cancer, T-cell acute lymphoblastic leukemia, prostate cancer, and glioma[3][6]. Pharmacologically, it is indirectly targeted by selective CDK4/6 inhibitors (e.g., palbociclib) used in cancer therapy, and abnormal expression levels serve as biomarkers for diagnosis and therapy stratification[3].

Other names

G1/S-specific cyclin-D3CCND3PRAD1Cyclin-D3Cyd3

Inhibition of CDK4/6 activity to block Cyclin D3—CDK kinase function and prevent cell cycle progression from G1 to S phase