Insulin Receptor Substrate 1 Phospho-Ser639 (IRS1 pS639) Antibody

Background

IRS1 is a key adaptor protein that mediates insulin and insulin-like growth factor (IGF) signaling by interacting with the insulin receptor (IR) and IGF-1 receptor. Upon receptor activation, IRS1 is phosphorylated on tyrosine residues, recruiting downstream effectors such as PI3K and Grb2 to activate pathways like PI3K/Akt and Ras/MAPK. IRS1 regulates glucose uptake, metabolism, cell growth, and survival, playing a central role in insulin signaling. It is highly expressed in insulin-sensitive tissues like muscle, liver, and adipose. Dysregulation of IRS1 is associated with insulin resistance, obesity, type 2 diabetes, and cancer, where aberrant signaling promotes proliferation and survival. Knockout studies show growth retardation, metabolic abnormalities, and impaired glucose homeostasis, underscoring its importance in metabolism and cellular signaling.