What is the Origin of IRS-1?

The term is an abbreviation for "Insulin Receptor Substrate 1," directly naming the protein based on its function and its hierarchical position in the signaling pathway. It belongs to a family of homologous proteins that share the role of transmitting the signal from the insulin receptor to the cell's internal machinery.

What is the Mechanism of IRS-1?

The mechanism begins with insulin binding to the extracellular domain of its receptor, triggering autophosphorylation of the receptor's intracellular domain. This activated receptor then phosphorylates multiple tyrosine residues on the IRS-1 protein. Once phosphorylated, IRS-1 acts as a scaffold, recruiting and activating various effector proteins, such as Phosphatidylinositol 3-Kinase (PI3K). The PI3K pathway is particularly important as it ultimately leads to the translocation of GLUT4 glucose transporters to the cell membrane, facilitating glucose entry and mediating the major metabolic effects of insulin.

IRS-1

Meaning

IRS-1, or Insulin Receptor Substrate 1, is a key intracellular signaling protein that acts as a crucial molecular link in the signal transduction cascade initiated by insulin binding to its cell surface receptor. Upon activation, the insulin receptor phosphorylates IRS-1, which then serves as a docking site for multiple downstream signaling molecules. This protein is essential for mediating the metabolic actions of insulin, particularly glucose uptake and utilization in muscle and fat cells. Dysfunctional IRS-1 signaling is a central feature in the pathogenesis of insulin resistance and Type 2 Diabetes Mellitus.