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Insulin Receptor Substrate

Meaning

Insulin Receptor Substrates (IRS) are a family of ubiquitous intracellular docking proteins that serve as crucial immediate signal transducers downstream of the activated insulin receptor. Upon insulin binding, the tyrosine kinase domain of the receptor phosphorylates specific tyrosine residues on the IRS proteins, creating binding sites for numerous other signaling molecules. These phosphorylation events are the essential first step in propagating the insulin signal that ultimately leads to metabolic effects like glucose uptake and protein synthesis.