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IRS Protein Phosphorylation

Meaning

IRS Protein Phosphorylation describes the post-translational modification of Insulin Receptor Substrate (IRS) proteins, a critical early step in the intracellular signaling cascade initiated by insulin and certain growth factors. The addition of phosphate groups to specific serine, threonine, or tyrosine residues on IRS proteins acts as a molecular switch, propagating the hormonal signal downstream to regulate metabolic processes like glucose uptake and protein synthesis. Impaired phosphorylation, particularly increased serine phosphorylation, is a hallmark mechanism contributing to insulin resistance and metabolic syndrome. This process represents a key regulatory node in metabolic integration.