GMNN Protein, Human

GMNN protein functions as a key inhibitor of DNA replication by preventing the incorporation of the MCM complex into the pre-replication complex (pre-RC). It undergoes degradation during the mitotic phase, enabling replication in the subsequent cell cycle. Additionally, GMNN inhibits the histone acetyltransferase activity of KAT7/HBO1 in a CDT1-dependent manner, suppressing histone H4 acetylation and DNA replication licensing. It also plays a role in controlling the transcriptional activity of a subset of Hox proteins, linking them to cell proliferation regulation. GMNN forms homotetramers and interacts with CDT1, existing in both 'permissive' heterotrimers and 'inhibitory' heterohexamers. The protein interacts with IDAS, directing GMNN to the nucleus, and forms a heterodimer with MCIDAS, which has lower affinity for CDT1 compared to the GMNN homodimer. Furthermore, GMNN engages in interactions with a subset of Hox proteins, with varying affinities, and interacts with LRWD1 from G1/S to mitosis.