📡
Signal Transduction
Vertebrates
Insulin Signaling Pathway
Insulin receptor activation driving glucose uptake and anabolic metabolism.
Overview
Insulin binds to the insulin receptor (IR), a receptor tyrosine kinase, triggering autophosphorylation and recruitment of IRS proteins. IRS activates PI3K/AKT, promoting GLUT4 translocation to the membrane for glucose uptake, glycogen synthesis (via GSK-3β inhibition), protein synthesis (via mTOR), and lipogenesis. The RAS-MAPK branch mediates mitogenic effects. Insulin resistance involves impaired signaling at multiple nodes.
Cellular Location
Membrane → Cytoplasm
Clinical Significance
Central to glucose homeostasis; insulin resistance underlies type 2 diabetes and metabolic syndrome; therapeutic targets include IR, IRS, PI3K, and GLUT4.