PP2A1, Protein Phosphatase 2A1
Source: Bovine kidney
Purity: > 90% by SDS-PAGE, subunit apparent Mr’s ~ 36-, 55- 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 PP2A1 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 2A1; PP2A1
GloboZymes PP2A1 preparations represent homogenous preparations of a heterotrimeric form of the phosphatase. These preparations are composed of A/PR65 , 55-kDa B and 36-kDa catalytic subunits. They are used to study enzyme kinetics and regulation, to dephosphorylate target substrates, and to evaluate the effects of test substances on the activity of the phosphatase.
Figure: SDS-PAGE pattern of purified preparation of PP2A1 showing, from top to bottom, the A/PR65 65-kDa, 55-kDa B and 36-kDa catalytic subunits. The gel was stained with Coomassie Blue.
Background: Protein phosphatase 2A (PP2A) is a growth and tumor suppressor. It is a multifunctional divalent cation-independent protein serine/threonine phosphatase involved in regulating 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. They also include transcription factors and key regulatory enzymes involved in metabolism. The tumor promoter okadaic acid potently inhibits PP2A. The phosphatase is also inhibited potently by two cancer-associated cellular proteins, I1PP2A and I2PP2A. During viral transformation, the SV40 small t antigen replaces the B subunit and subverts the physiological function of a subset of heterotrimeric PP2A complexes in a substrate-selective manner.
References: Biochem J 287, 1019-1022; Proc Natl Acad Sci USA 90, 2500-2504; Trends Cell Biol 4, 287-291; Ann Rev Cell Biol 10, 55-86; Biochem J 353, 417
