Insulin receptor kinase domain (IRK)

The **insulin receptor kinase domain** is the intracellular catalytic domain of the insulin receptor, a member of the receptor tyrosine kinase (RTK) family[1][2]. Upon insulin binding to the extracellular α subunit, the receptor dimer undergoes autophosphorylation of key tyrosine residues within the cytoplasmic β subunit's kinase domain, triggering downstream signaling cascades that regulate glucose uptake, metabolism, growth, and cell proliferation[2][5][7]. The kinase domain features an ATP binding site and an activation loop, whose phosphorylation relieves autoinhibition and enables substrate phosphorylation[7]. Dysfunction or dysregulation of this kinase domain plays a central role in diabetes and has implications in cancer and other metabolic diseases due to its central role in cell signaling and growth regulation[6][7][9]. The kinase domain is targeted by experimental drugs designed to inhibit aberrant signaling, especially in oncology, but such targeting carries a risk of toxicity due to interference with normal metabolic processes[6].

Other names

Insulin receptor tyrosine kinase domainIRKINSR kinase domainInsulin receptor β subunit kinase domain

Ligand (insulin) binding induces receptor autophosphorylation, activating intrinsic tyrosine kinase activity and subsequent downstream signaling[2][5][7] Small-molecule inhibitors block ATP binding or stabilize inactive kinase conformations, inhibiting activity[6][7]