The catalytic (C) subunit of protein phosphatase 2A. The protein is shown in rainbow color with the N-terminus in blue and the C-terminus in red. The methylatedcarboxyl group of the C-terminal leucine residue is shown in white. The purple spheres are two catalytically required manganese ions and the dark gray compound at center is a peptidomimetic toxin, microcystin, occupying the active site. From PDB: 2IAE.[1]
Protein phosphatase 2 (PP2), also known as PP2A, is an enzyme that in humans is encoded by the PPP2CAgene.[2][3] The PP2A heterotrimericprotein phosphatase is ubiquitously expressed, accounting for a large fraction of phosphatase activity in eukaryotic cells.[4] Its serine/threonine phosphatase activity has a broad substrate specificity and diverse cellular functions. Among the targets of PP2A are proteins of oncogenic signaling cascades, such as Raf, MEK, and AKT, where PP2A may act as a tumor suppressor.
^Jones TA, Barker HM, da Cruz e Silva EF, Mayer-Jaekel RE, Hemmings BA, Spurr NK, Sheer D, Cohen PT (1993). "Localization of the genes encoding the catalytic subunits of protein phosphatase 2A to human chromosome bands 5q23→q31 and 8p12→p11.2, respectively". Cytogenetics and Cell Genetics. 63 (1): 35–41. doi:10.1159/000133497. PMID8383590.
