PI3K Antibody (p85 beta)

Phosphatidylinositol 3-kinase regulatory subunit 2, also called p85-Beta, PIK3R2 and PIK3, is an enzyme that in humans is encoded by the PIK3R2 gene. The NS1 protein from various influenza strains bind p85-beta, but not p85-alpha. Binding of p85-beta and activation of PI3K required tyr89 of NS1, and mutant viruses expressing NS1 with a tyr89-to-phe substitution grew more slowly in cell culture than wildtype viruses. Using mouse embryonic fibroblasts, Park et al. showed that, in addition to regulating PI3K function, p85-alpha/beta regulated the function of Xbp1s, a transcription factor that orchestrates the unfolded protein response (UPR) following endoplasmic reticulum (ER) stress. Overexpression of the protein in livers of ob/ob mice increased glucose tolerance and reduced blood glucose concentrations.