Editing Maturation promoting factor (section)

{{Refimprove|date=September 2014}}
'''Maturation-promoting factor''' (abbreviated '''MPF''', also called '''mitosis-promoting factor''' or '''M-Phase-promoting factor''') is  the [[Cyclin-dependent kinase complex|cyclin–Cdk complex]] that was discovered first in frog eggs.<ref name="Smith_1971">{{cite journal | vauthors = Smith LD, Ecker RE | title = The interaction of steroids with Rana pipiens Oocytes in the induction of maturation | journal = Developmental Biology | volume = 25 | issue = 2 | pages = 232–47 | date = June 1971 | pmid = 5562852 | doi = 10.1016/0012-1606(71)90029-7 }}</ref><ref name = "Masui_1971">{{cite journal | vauthors = Masui Y, Markert CL | title = Cytoplasmic control of nuclear behavior during meiotic maturation of frog oocytes | journal = The Journal of Experimental Zoology | volume = 177 | issue = 2 | pages = 129–45 | date = June 1971 | pmid = 5106340 | doi = 10.1002/jez.1401770202 | bibcode = 1971JEZ...177..129M }}</ref>  It stimulates the [[mitotic]] and [[meiotic]] phases of the [[cell cycle]]. MPF promotes the entrance into mitosis (the M phase) from the [[G2 phase|G<sub>2</sub> phase]] by phosphorylating multiple proteins needed during mitosis. MPF is activated at the end of G<sub>2</sub> by a [[phosphatase]], which removes an inhibitory phosphate group added earlier.

The MPF is also called the M phase kinase because of its ability to phosphorylate target proteins at a specific point in the cell cycle and thus control their ability to function.