Recombinant human PI 3 Kinase p110 delta + PI 3 Kinase p85 alpha protein (ab60892)

PI3-Kinases (PI3-Ks) are a family of lipid kinases that are implicated in signal transduction. PI3-K consists of two subunits; p85 and p110. The p85 subunit localize PI3-K activity to the plasma membrane while the p110 subunit contains the catalytic domain of PI3-K. Four isoforms of p110 has been found; the alpha, beta, gamma, and the delta subunit. The delta isoform is predominantly expressed in leukocytes and has been shown to interact with p85 and GTP-bound Ras via its SH2/SH3 domain. The enzyme phosphatidylinositol 3 kinase (PI3 kinase) is a lipid kinase that is thought to phosphorylate second messengers in growth signalling pathways. PI3K exists as a heterodimer of catalytic 110 kDa (p110) and regulatory 85 kDa (p85, p50 or p55) subunits. The p85 unit consists of two closely related proteins: p85 alpha, which binds tightly to the catalytic subunit and p85 beta, a protein of unknown function. They share 62% amino acid sequence identity. p85 alpha lacks PI3 kinase activity, but may serve as regulator of the catalytic subunit, p110, by acting as the link between PI3K and the ligand activated receptor. Both isoforms bind to activated receptors and serve as tyrosine kinase substrates.

Cytoplasmic