Insulin Receptor Substrate 1 (IRS-1) tagged posts

1) Fasting or obesity induces SDF-1 expression in adipocytes. 2) Its autocrine action activates ERK signaling. 3) SDF-1-induced ERK signal concomitantly induces serine phosphorylation of IRS-1 protein, and degrades IRS-1 protein. This attenuates 4) insulin-mediated Akt phosphorylation and 5) glucose uptake. Credit: Osaka University

Scientists at Osaka University discovered that Stromal derived factor-1 (SDF-1) secreted from adipocytes reduced the effectiveness of insulin in adipocytes and decreased insulin-induced glucose uptake. Insulin is a hormone made by the pancreas and helps cells to take in glucose from the blood. Insulin binds to insulin receptors to activate Insulin Receptor Substrate 1 (IRS-1), taking in sugar through phosphorylation of Akt...