Progression of cells from interphase to mitosis involves alterations in cell structures and activities. The transition from G2 to M phase is induced by M phase-promoting factor (MPF). In M phase, many proteins are phosphorylated directly by MPF or indirectly by kinases activated by MPF. These M phase phosphoproteins (MPPs), also known as MPHOSPHs, permit disassembly of interphase structures and generation of M phase enzymatic activities and structures. MPP9 (M-phase phosphoprotein 9), also known as MPHOSPH9, is a 1,031 amino acid peripheral membrane protein of the Golgi apparatus that exists as two alternatively spliced isoforms. The gene encoding MPP9 maps to human chromosome 12, which encodes over 1,100 genes and comprises approximately 4.5% of the human genome. Chromosome 12 is associated with a variety of diseases and afflictions, including hypochondrogenesis, achondrogenesis, Kniest dysplasia, Noonan syndrome and trisomy 12p.
M-phase phosphoprotein 9; MPHOSPH9