Insulin-like growth factor receptor (IGF-1R) is a transmembrane receptor protein that plays a crucial role in mediating the cellular responses to insulin-like growth factors (IGFs). This receptor is a member of the insulin receptor family and is primarily expressed on the surface of various cell types, such as muscle, bone, and adipose tissue cells.
The IGF-1R consists of two extracellular α subunits and two transmembrane β subunits that possess an intracellular tyrosine kinase domain. When IGF-1 or IGF-2 ligands bind to the α subunits, they induce a conformational change that activates the receptor's tyrosine kinase activity. This initiates a signaling cascade that regulates processes such as cell growth, proliferation, differentiation, and survival.
Activation of IGF-1R triggers the phosphorylation of intracellular substrates, including insulin receptor substrate proteins (IRS), facilitating the recruitment of other downstream signaling molecules such as PI3K/AKT and MAPK/ERK pathways. These signaling pathways are implicated in the regulation of cell growth, metabolism, and survival.
Dysregulation of IGF-1R signaling has been associated with various pathological conditions, including cancer. Increased IGF-1R activation can promote tumor development, metastasis, and resistance to therapies. Consequently, IGF-1R has emerged as a potential therapeutic target for the treatment of cancers, and several IGF-1R inhibitors have been developed and tested in clinical trials.
In summary, the insulin-like growth factor receptor is a transmembrane receptor protein that mediates the cellular responses to insulin-like growth factors, regulating processes such as cell growth, proliferation, differentiation, and survival. Dysregulation of this receptor's signaling has
