CST, 4228T, Phospho-PI3 Kinase p85 (Tyr458)/p55 (Tyr199) Antibody

Polyclonal Antibody for studying PI3K p85 alpha (Tyr467) phosphate/PI3K p55 (Tyr199) phosphate/PI3K p85 beta (Tyr464) phosphate. Validated for Western Blotting,Immunoprecipitation. Available in 3 sizes. Highly specific and rigorously validated in-house, Phospho-PI3 Kinase p85 (Tyr458)/p55 (Tyr199) Antibody (CST #4228) is ready to ship. Product Usage Information Western Blotting: 1:1000 Immunoprecipitation: 1:50 Storage Supplied in 10 mM sodium HEPES (pH 7.5), 150 mM NaCl, 100 µg/ml BSA and 50% glycerol. Store at -20°C. Do not aliquot the antibody. Protocol Available protocols: Western Blotting, Immunoprecipitation Specificity / Sensitivity Phospho-PI3 Kinase p85 (Tyr458)/p55 (Tyr199) Antibody detects endogenous levels of p85/p55 only when phosphorylated at Tyr458/Tyr199. Species Reactivity: Mouse Source / Purification Polyclonal antibodies are produced by immunizing animals with a synthetic phosphopeptide corresponding to residues surrounding Tyr458 of mouse p85. Antibodies are purified by protein A and peptide affinity chromatography. Background Phosphoinositide 3-kinase (PI3K) catalyzes the production of phosphatidylinositol-3,4,5-triphosphate by phosphorylating phosphatidylinositol (PI), phosphatidylinositol-4-phosphate (PIP), and phosphatidylinositol-4,5-bisphosphate (PIP ). Growth factors and hormones trigger this phosphorylation event, which in turn coordinates cell growth, cell cycle entry, cell migration, and cell survival (1). PTEN reverses this process, and research studies have shown that the PI3K signaling pathway is constitutively activated in human cancers that have loss of function of PTEN (2). PI3Ks are composed of a catalytic subunit (p110) and a regulatory subunit. Various isoforms of the catalytic subunit (p110α, p110β, p110γ, and p110δ) have been isolated, and the regulatory subunits that associate with p110α, p110β, and p110δ are p85α and p85β (3). In contrast, p110γ associates with a p101 regulatory subunit that is unrelated to p85. Furthermore, p110γ is activated by βγ subunits of heterotrimeric G proteins (4). Protein extracts from 3T3-Src cells were profiled by PhosphoScan to identify phosphotyrosine peptides. Tyr458 of PI3K p85 and Tyr199 of PI3K p55 were among 180 phosphopeptides and 185 phosphotyrosine sites identified (5). Alternate Names 100% homology to SWISS-PROT Q92569; AGM7; DKFZp686P05226; FLJ41892; GRB1; IMD36; MPPH; MPPH1; p55; p55-GAMMA; P55G; p55PIK; p85; p85-ALPHA; p85-BETA; P85A; P85B; Phosphatidylinositol 3-kinase 55 kDa regulatory subunit gamma; Phosphatidylinositol 3-kinase 85 kDa regulatory subunit alpha; Phosphatidylinositol 3-kinase 85 kDa regulatory subunit beta; Phosphatidylinositol 3-kinase regulatory subunit alpha; Phosphatidylinositol 3-kinase regulatory subunit beta; Phosphatidylinositol 3-kinase regulatory subunit gamma; phosphatidylinositol 3-kinase-associated p-85 alpha; phosphatidylinositol 3-kinase, regulatory subunit, polypeptide 1 (p85 alpha); phosphatidylinositol 3-kinase, regulatory subunit, polypeptide 2 (p85 beta); phosphatidylinositol 3-kinase, regulatory subunit, polypeptide 3 (p55, gamma); phosphatidylinositol 3-kinase, regulatory, 1; phosphoinositide-3-kinase regulatory subunit 1; phosphoinositide-3-kinase regulatory subunit 2; phosphoinositide-3-kinase regulatory subunit 3; phosphoinositide-3-kinase regulatory subunit alpha; phosphoinositide-3-kinase regulatory subunit beta; phosphoinositide-3-kinase, regulatory subunit 1 (alpha); phosphoinositide-3-kinase, regulatory subunit 2 (beta); phosphoinositide-3-kinase, regulatory subunit 2 (p85 beta); phosphoinositide-3-kinase, regulatory subunit 3 (gamma); phosphoinositide-3-kinase, regulatory subunit 3 (p55, gamma); phosphoinositide-3-kinase, regulatory subunit, polypeptide 2 (p85 beta); phosphoinositide-3-kinase, regulatory subunit, polypeptide 3 (p55, gamma); PI3-kinase regulatory subunit alpha; PI3-kinase regulatory subunit beta; PI3-kinase regulatory subunit gamma; PI3-kinase subunit p55-gamma; PI3-kinase subunit p85-alpha; PI3-kinase subunit p85-beta; PI3K regulatory subunit alpha; PI3K regulatory subunit beta; PI3K regulatory subunit gamma; PIK3R1; PIK3R2; PIK3R3; PtdIns-3-kinase regulatory subunit alpha; PtdIns-3-kinase regulatory subunit beta; PtdIns-3-kinase regulatory subunit gamma; PtdIns-3-kinase regulatory subunit p55-gamma; PtdIns-3-kinase regulatory subunit p85-alpha; PtdIns-3-kinase regulatory subunit p85-beta Specification REACTIVITY: M SENSITIVITY: Endogenous MW (kDa): 60 and 85 SOURCE: Rabbit