IGF1 receptor [alphaIR3]

GWB-C9EA19

IgG1

Human

HepG2 cells

Plasma membrane

0. 05 M sodium phosphate buffer 0. 2% gelatin and ?0. 1% sodium azide.

Plasma membrane There are two kinds of IGF receptors based on their relative affinities for IGFI versus IGFII. The IGFI receptor prefers IGFI over IGFII and weakly binds insulin. IGFI receptor is a disulfide-linked heterotetrameric transmembrane protein consisting of two alpha (130 kD) and two beta (95 kD) subunits. Both the alpha and beta subunits are encoded within a single receptor precursor cDNA. The IGFI receptor is therefore similar in structure to the insulin receptor. The proreceptor polypeptide is proteolytically cleaved and disulfide-linked to yield the mature heterotetrameric receptor. The alpha subunit of the IGFI receptor is extracellular while the beta subunit has an extracellular domain a transmembrane domain and a cytoplasmic tyrosine kinase domain. The IGFI receptor is highly expressed in all cell types and tissues. Essentially all of the biological activities of IGFI and II have been shown to be mediated via the IGFI receptor.

ATP + a [protein]-L-tyrosine = ADP + a [protein]-L-tyrosine phosphate.

Tetramer of 2 alpha and 2 beta chains linked by disulfide bonds. The alpha chains contribute to the formation of the ligand-binding domain while the beta chain carries the kinase domain. Interacts with PIK3R1 and with the PTB/PID domains of IRS1 and SHC1 in vitro when autophosphorylated on tyrosine residues.

Expressed in a variety of tissues.

Phosphorylation of Tyr-980 is required for IRS1- and SHC1-binding.

Belongs to the protein kinase superfamily. Tyr protein kinase family. Insulin receptor subfamily.

Contains 1 protein kinase domain.