function:Binds to activated (phosphorylated) protein-tyrosine kinases through its SH2 domain and regulates their kinase activity. During insulin stimulation, it also binds to IRS-1.,similarity:Belongs to the PI3K p85 subunit family.,similarity:Contains 2 SH2 domains.,subunit:Heterodimer of a p110 (catalytic) and a p55 (regulatory) subunits.,tissue specificity:Highest levels in brain and testis. Lower levels in adipose tissue, kidney, heart, lung and skeletal muscle.,
cytosol,phosphatidylinositol 3-kinase complex,
Highest levels in brain and testis. Lower levels in adipose tissue, kidney, heart, lung and skeletal muscle.