Rabbit Anti-Human IRS1 (phospho Ser616) monoclonal antibody for FC, ICC, IF, WB. Insulin receptor substrate 1 (IRS1) is encoded by the IRS1 gene located on chromosome 2. IRS1 is a member of the IRS family of adaptor molecules along with IRS 2 and 3, which play a critical role in insulin signaling. Insulin binding to its cognate receptor is followed by autophosphorylation on tyrosine residues and activation of the Insulin Receptor (IR). IRS1 contains pleckstrin homology (PH) and phosphotyrosine binding (PTB) domains at the N-terminus which directs IRS1 to IR. Phosphorylation of IRS1 on tyrosine residues is known to enhance insulin signaling while phosphorylation on Serine/Threonine residues can increase or decrease signaling. IRS1 interacts with PI3k and other signaling proteins such as Grb2 via the SRC homology domain (SH2 or SH3) for activation of both PI3k- Akt and MAP kinase signaling pathways.