PP2A2, Protein Phosphatase 2A2
Source: Bovine kidney
Purity: > 90% by SDS-PAGE, subunit apparent Mr’s ~ 36- and 65- kDa
Supplied: In 50 μl 50 mM Tris-HCl pH 7.0 buffer containing 14 mM β-mercaptoethanol, 1 mM benzamidine, 0.1 mM phenylmethanesulfonyl fluoride, 1 mM EDTA and 50% glycerol.
Activity: ~ 2000 units/mg with myelin basic protein (MBP) as substrate. One unit is the amount of PP2A2 that releases 1 nmol of inorganic phosphate from 32P-labeled MBP per min. Maintain preparations in aliquots at -70° C. Avoid repeated thawing.
Synonyms: Protein Phosphatase 2A2; PP2A2
Background: Protein phosphatase 2A (PP2A) is a divalent cation-independent multifunctional protein serine threonine phosphatase. PP2A regulates numerous cellular processes including the cell cycle, growth and differentiation. Physiological targets of PP2A include cell surface receptors and ion channels, and protein kinases involved in mitogenic signaling and the cell cycle. PP2A also acts on numerous transcription factors as well as key regulatory enzymes in metabolism. PP2A is a growth and tumor suppressor. It is inhibited potently by tumor promoters such as okadaic acid. It is also inhibited potently by two cancer-associated cellular proteins, I1PP2A and I2PP2A/SET. In addition, the SV40 small t antigen replaces the B subunit of PP2A during viral transformation. This subverts the physiological function of a subset of PP2A complexes in a substrate selective manner.
Figure: Purified preparation of bovine kidney PP2A2 was subjected to SDS-PAGE. The gel was stained with Coomassie Blue. The 65-kda A (top) and 36-kDa C (bottom) subunits are seen.
Protein Phosphatase 2A2 (PP2A2) is a dimeric form of PP2A. It contains A (65 kDa) and C (36 kDa) subunits but lacks the B subunit present in PP2A1. GloboZymes purified PP2A2 preparations are used to study enzyme kinetics and regulation. They are used to dephosphorylate target substrates and to evaluate the effects of test substances on the activity of the phosphatase. The preparations can also be used for determining the role of the missing B subunit of the enzyme.
References: Biochem J 287: 1019; Proc Natl Acad Sci USA 90: 2500
