PATHOLOGY

Detailed explanation-1: -At the end of mitosis both SPF and MPF activities disappear because their cyclin subunits are degraded [5]. During G1 phase of the following cell cycle, when both SPF and MPF activities are low [6], origins of replication can be relicensed for another round of DNA synthesis [7, 8].

Detailed explanation-2: -In addition to driving the events of M phase, MPF also triggers its own destruction by activating the anaphase-promoting complex/cyclosome (APC/C), a protein complex that causes M cyclins to be destroyed starting in anaphase.

Detailed explanation-3: -Two different mechanisms are proposed: (i) cyclin and p34 kinase combine to form an oligomer with MPF activity; (ii) cyclin enzymatically activates the passage from inactive pre-MPF to active MPF, with the postulate that MPF initiates cyclin degradation.

Detailed explanation-4: -In animal cells, MPF is cytoplasmic in interphase and is translocated into the nucleus after mitosis has begun, after which it associates with the mitotic apparatus until the cyclins are degraded in anaphase.

Detailed explanation-5: -It stimulates the mitotic and meiotic phases of the cell cycle. MPF promotes the entrance into mitosis (the M phase) from the G2 phase by phosphorylating multiple proteins needed during mitosis. MPF is activated at the end of G2 by a phosphatase, which removes an inhibitory phosphate group added earlier.