Species predicted to react based on 100% sequence homology:Mouse
Specificity / Sensitivity
Phospho-IRS-1 (Ser789) Antibody detects transfected IRS-1 only when phosphorylated at serine 789. This antibody does not cross-react with related phospho-proteins.
Source / Purification
Polyclonal antibodies are produced by immunizing animals with a synthetic phosphopeptide corresponding to residues surrounding Ser789 of mouse IRS-1 (equivalent to Ser794 of human IRS-1). Antibodies are purified by protein A and peptide affinity chromatography.
Background
Insulin receptor substrate 1 (IRS-1) is one of the major substrates of the insulin receptor kinase (1). IRS-1 contains multiple tyrosine phosphorylation motifs that serve as docking sites for SH2-domain containing proteins that mediate the metabolic and growth-promoting functions of insulin (2-4). IRS-1 also contains over 30 potential serine/threonine phosphorylation sites. Ser307 of IRS-1 is phosphorylated by JNK (5) and IKK (6) while Ser789 is phosphorylated by SIK-2, a member of the AMPK family (7). The PKC and mTOR pathways mediate phosphorylation of IRS-1 at Ser612 and Ser636/639, respectively (8,9). Phosphorylation of IRS-1 at Ser1101 is mediated by PKCθ and results in an inhibition of insulin signaling in the cell, suggesting a potential mechanism for insulin resistance in some models of obesity (10).