PIK3R1

(redirected from PI3-kinase subunit p85-alpha)

PIK3R1

A gene on chromosome 5q13.1 that encodes a regulatory subunit of phosphoinositide 3-kinase. PIK3R1 binds to activated (phosphorylated) protein-Tyr kinases through its SH2 domain and acts as an adapter, mediating the association of the p110 catalytic unit to the plasma membrane. It is necessary for the insulin-driven increase in glucose uptake and glycogen synthesis in insulin-sensitive tissues, and it plays an important role in signalling in response to FGFR1, FGFR2, FGFR3, FGFR4, KITLG/SCF, KIT, PDGFRA and PDGFRB. PIK3R1 also plays a role in ITGB2 signalling.