IPv6

Overview

The Insulin Receptor (INSR) is a transmembrane receptor that is activated by insulin, IGF-I, and IGF-II. It belongs to the large class of tyrosine kinase receptors and plays a crucial role in the regulation of glucose homeostasis. The INSR is encoded by the INSR gene located on chromosome 19 in humans.

Structure

The insulin receptor is a heterotetrameric protein composed of two extracellular α subunits and two transmembrane β subunits. The α subunits are responsible for insulin binding, while the β subunits possess intrinsic tyrosine kinase activity. Upon insulin binding, the receptor undergoes autophosphorylation, which triggers a cascade of downstream signaling pathways.

Function

The primary function of the insulin receptor is to mediate the effects of insulin, a hormone critical for the regulation of glucose uptake and metabolism. Upon activation, the receptor initiates a signaling cascade involving the PI3K/AKT pathway and the MAPK/ERK pathway, leading to increased glucose uptake, glycogen synthesis, and lipid metabolism.

Clinical Significance

Mutations in the INSR gene can lead to insulin resistance, a hallmark of type 2 diabetes mellitus. Additionally, overexpression or dysregulation of the insulin receptor has been implicated in various cancers, as it can promote cell proliferation and survival.

Research and Therapeutic Implications

Understanding the structure and function of the insulin receptor is crucial for developing therapeutic strategies for diabetes and cancer. Current research focuses on designing insulin receptor agonists and antagonists, as well as exploring the receptor's role in metabolic and proliferative diseases.

Also see

• Insulin
• Type 2 diabetes mellitus
• Tyrosine kinase receptors
• PI3K/AKT pathway
• MAPK/ERK pathway