Geminin
From Wikipedia, the free encyclopedia
Geminin is a protein found in the nucleus of eukaryotic cells. It is a negative regulator of DNA replication. Inhibtion of geminin using RNAi results in an extra round of DNA replication in cancerous and non-cancerous human cell lines.
The protein consists of 200 residues. When cdt1 is phosphorylated via the cycA:cdk2 and dbf2:cdc7 complexes, it is targetted for degradation by SCF. Geminin inhibits remaining cdt1, preventing binding of the MCM complex to the origin or replication.
Geminin is absent during G1 phase and accumulates through S, G2 and M phase of the cell cycle. Geminin levels drop around the anaphase/telophase marker of mitosis.
