Minichromosome Maintenance Deficient 3 Associated Protein (MCM3AP)

MCM3APwas reported to have phosphorylation-dependent DNA-primase activity, which was up-regulated in antigen immunization induced germinal center. This protein was demonstrated to be an acetyltransferase that acetylates MCM3 and plays a role in DNA replication. The mutagenesis of a nuclear localization signal of MCM3 affects the binding of this protein with MCM3, suggesting that this protein may also facilitate MCM3 nuclear localization.The predicted 721-amino acid MAP80 has an estimated pI of 5.1. Antibodies against MAP80 detected an 80-kD protein on Western blots of HeLa cell extracts. The authors found that MAP80 coimmunoprecipitated with MCM3 in HeLa cell extracts. In the presence of a small amount of cytosol, recombinant MAP80 facilitated the nuclear import of a chimeric GFP-MCM3 protein.