Insulin-like growth factor 1 receptor

Insulin-like growth factor 1 receptor (IGF1R) is a receptor that binds insulin-like growth factor 1 (IGF1) with high affinity. This receptor is a type of tyrosine kinase receptor, which is activated by a phosphorylation process. The IGF1R plays a crucial role in growth and development, particularly during fetal development, and it continues to have important functions in adults.

Structure

The IGF1R is a transmembrane receptor that is present on the cell surface. It is composed of two alpha subunits and two beta subunits, which are linked by disulfide bonds. The alpha subunits are located extracellularly and are responsible for ligand binding, while the beta subunits span the membrane and have an intracellular domain with tyrosine kinase activity.

Function

Upon binding of the ligand IGF1, the IGF1R undergoes autophosphorylation, which activates the receptor's intrinsic tyrosine kinase activity. This leads to the phosphorylation of several intracellular substrates, initiating a cascade of intracellular signaling events. These signals regulate various cellular processes, including cell proliferation, cell differentiation, and apoptosis.

The IGF1R is also involved in longevity, as studies have shown that reduced function of this receptor can lead to increased lifespan in some organisms.

Clinical significance

Abnormalities in the IGF1R can lead to various health problems. Overexpression of the receptor has been associated with several types of cancer, including breast cancer, lung cancer, and colorectal cancer. In these cases, the IGF1R promotes cell proliferation and inhibits apoptosis, contributing to tumor growth and progression.

On the other hand, mutations that impair the function of the IGF1R can lead to growth retardation and developmental delays, as seen in conditions such as Laron syndrome.

See also

• Insulin-like growth factor 1
• Tyrosine kinase receptor
• Laron syndrome