The IGF I receptor refers to a cell surface receptor protein that is primarily responsible for binding to and mediating the effects of insulin-like growth factor I (IGF-I). It belongs to the family of tyrosine kinase receptors and is an integral component of the IGF system, which plays a vital role in regulating cell growth, differentiation, and survival.
The IGF I receptor is found in various tissues throughout the body, including muscle, liver, bone, and adipose tissue. It is composed of two subunits: a ligand-binding extracellular α-subunit and a transmembrane β-subunit possessing tyrosine kinase activity. Upon binding IGF-I, the receptor undergoes autophosphorylation, activating its kinase domain and initiating intracellular signaling cascades.
Activation of the IGF I receptor leads to a multitude of cellular responses, including cell proliferation, differentiation, and the inhibition of programmed cell death (apoptosis). It also exerts significant effects on glucose metabolism and stimulates protein synthesis.
Alterations or dysregulation of the IGF I receptor signaling pathway have been associated with many pathological conditions, including cancer, insulin resistance, and cardiovascular diseases. Consequently, the IGF I receptor has emerged as a potential therapeutic target for the treatment of such disorders.
In summary, the IGF I receptor is a vital component of the IGF system, responsible for transmitting signals from IGF-I, promoting cell growth, differentiation, and survival in various tissues throughout the body.
