InterPro domain: IPR026907

Cyclin-D1-binding protein 1 (CCNDBP1, also known as GCIP) is a helix-loop-helix protein that may negatively regulate cell cycle progression and could function in tumour suppression [ 1 ]. It may act, at least in part, via inhibition of the cyclin-D1/CDK4 complex, thereby preventing phosphorylation of RB1 and blocking E2F-dependent transcription [ 2 , 3 ].

1. GCIP/CCNDBP1, a helix-loop-helix protein, suppresses tumorigenesis. J. Cell. Biochem. 100, 1376-86
2. GCIP, a novel human grap2 and cyclin D interacting protein, regulates E2F-mediated transcriptional activity. J. Biol. Chem. 275, 20942-8
3. Maid (GCIP) is involved in cell cycle control of hepatocytes. Hepatology 45, 404-11