NCIt definition : Geminin (209 aa, 24 kDa) is encoded by the human GMNN gene. This protein is involved
in the modulation of DNA replication.;
NCIt note : Geminin inhibits DNA replication during S, G2, and M phases by sequestering CDT1,
a replication initiation factor necessary for MCM loading, to prevent the incorporation
of MCM complex into prereplication complex. Geminin has a destruction box sequence
(RRTLKVIQP) and is ubiquitinated by the anaphase-promoting complex. Geminin destruction
at the metaphase-anaphase transition permits replication in the succeeding cell cycle.
Geminin may also inhibit inappropriate origin firing by targeting CDT1. In the normal
cell cycle, CDT1 is present only in G1 and S phases, whereas geminin is present in
S and G2 phases.;