p110α+/− p110β+/− mice have decreased p110 and p85 levels in liver and muscle. (a) PI3K assays in liver (for anti-p110α immunoprecipitation [IP]: wild type [WT], n = 3; p110α+/− p110β+/−, n = 3; for anti-p110β IP: WT, n = 3; p110α+/− p110β+/−, n = 6) and skeletal muscle (for anti-p110β and anti-p110α IP: WT, n = 3; p110α+/− p110β+/−, n = 3) from 4-month-old WT and p110α+/− p110β+/− mice. Results are means ± standard errors of the means and represent one of two experiments. (b) p110α, p110β, and p85 protein levels in liver (left) and skeletal muscle (right) from 4-month-old mice. IP was performed on 2 mg of muscle or 2 mg of liver from WT or p110α+/− p110β+/− mice. A representative experiment is shown. Each lane represents a single mouse.