IGF1R

This receptor binds insulin-like growth factor with a high affinity. It has tyrosine kinase activity. The insulin-like growth factor I receptor plays a critical role in transformation events. Cleavage of the precursor generates alpha and beta subunits. It is highly overexpressed in most malignant tissues where it functions as an anti-apoptotic agent by enhancing cell survival. Alternatively spliced transcript variants encoding distinct isoforms have been found for this gene. [provided by RefSeq, May 2014]

Insulin Like Growth Factor 1 Receptor

Receptor tyrosine kinase which mediates actions of insulin-like growth factor 1 (IGF1). Binds IGF1 with high affinity and IGF2 and insulin (INS) with a lower affinity. The activated IGF1R is involved in cell growth and survival control. IGF1R is crucial for tumor transformation and survival of malignant cell. Ligand binding activates the receptor kinase, leading to receptor autophosphorylation, and tyrosines phosphorylation of multiple substrates, that function as signaling adapter proteins including, the insulin-receptor substrates (IRS1/2), Shc and 14-3-3 proteins. Phosphorylation of IRSs proteins lead to the activation of two main signaling pathways: the PI3K-AKT/PKB pathway and the Ras-MAPK pathway. The result of activating the MAPK pathway is increased cellular proliferation, whereas activating the PI3K pathway inhibits apoptosis and stimulates protein synthesis. Phosphorylated IRS1 can activate the 85 kDa regulatory subunit of PI3K (PIK3R1), leading to activation of several downstream substrates, including protein AKT/PKB. AKT phosphorylation, in turn, enhances protein synthesis through mTOR activation and triggers the antiapoptotic effects of IGFIR through phosphorylation and inactivation of BAD. In parallel to PI3K-driven signaling, recruitment of Grb2/SOS by phosphorylated IRS1 or Shc leads to recruitment of Ras and activation of the ras-MAPK pathway. In addition to these two main signaling pathways IGF1R signals also through the Janus kinase/signal transducer and activator of transcription pathway (JAK/STAT). Phosphorylation of JAK proteins can lead to phosphorylation/activation of signal transducers and activators of transcription (STAT) proteins. In particular activation of STAT3, may be essential for the transforming activity of IGF1R. The JAK/STAT pathway activates gene transcription and may be responsible for the transforming activity. JNK kinases can also be activated by the IGF1R. IGF1 exerts inhibiting activities on JNK activation via phosphorylation and inhibition of MAP3K5/ASK1, which is able to directly associate with the IGF1R.

When present in a hybrid receptor with INSR, binds IGF1. PubMed:12138094 shows that hybrid receptors composed of IGF1R and INSR isoform Long are activated with a high affinity by IGF1, with low affinity by IGF2 and not significantly activated by insulin, and that hybrid receptors composed of IGF1R and INSR isoform Short are activated by IGF1, IGF2 and insulin. In contrast, PubMed:16831875 shows that hybrid receptors composed of IGF1R and INSR isoform Long and hybrid receptors composed of IGF1R and INSR isoform Short have similar binding characteristics, both bind IGF1 and have a low affinity for insulin.

Amyloid-beta clearance Source: ARUK-UCL
Axonogenesis Source: Ensembl
Cardiac atrium development Source: Ensembl
Cellular response to aldosterone Source: Ensembl
Cellular response to amyloid-beta Source: ARUK-UCL
Cellular response to angiotensin Source: Ensembl
Cellular response to dexamethasone stimulus Source: Ensembl
Cellular response to estradiol stimulus Source: Ensembl
Cellular response to glucose stimulus Source: GO_Central
Cellular response to insulin-like growth factor stimulus Source: Ensembl
Cellular response to mechanical stimulus Source: Ensembl
Cellular response to progesterone stimulus Source: Ensembl
Cellular response to testosterone stimulus Source: Ensembl
Cellular response to transforming growth factor beta stimulus Source: Ensembl
Cellular senescence Source: Ensembl
Cerebellum development Source: Ensembl
Dendritic spine maintenance Source: ARUK-UCL
Establishment of cell polarity Source: Ensembl
Estrous cycle Source: Ensembl
Glucose homeostasis Source: GO_Central
Hippocampus development Source: Ensembl
Immune response Source: BHF-UCL
Insulin-like growth factor receptor signaling pathway Source: UniProtKB
Insulin receptor signaling pathway Source: ARUK-UCL
Negative regulation of apoptotic process Source: UniProtKB
Negative regulation of cholangiocyte apoptotic process Source: Ensembl
Negative regulation of hepatocyte apoptotic process Source: Ensembl
Negative regulation of MAPK cascade Source: GO_Central
Negative regulation of muscle cell apoptotic process Source: Ensembl
Peptidyl-tyrosine autophosphorylation Source: MGI
Phosphatidylinositol 3-kinase signaling Source: BHF-UCL
Phosphatidylinositol-mediated signaling Source: BHF-UCL
Positive regulation of axon regeneration Source: Ensembl
Positive regulation of cell migration Source: BHF-UCL
Positive regulation of cell population proliferation Source: BHF-UCL
Positive regulation of cold-induced thermogenesis Source: YuBioLab
Positive regulation of cytokinesis Source: Ensembl
Positive regulation of DNA metabolic process Source: Ensembl
Positive regulation of kinase activity Source: GO_Central
Positive regulation of MAPK cascade Source: GO_Central
Positive regulation of osteoblast proliferation Source: Ensembl
Positive regulation of phosphatidylinositol 3-kinase signaling Source: GO_Central
Positive regulation of protein-containing complex disassembly Source: ARUK-UCL
Positive regulation of protein kinase B signaling Source: GO_Central
Positive regulation of smooth muscle cell proliferation Source: Ensembl
Positive regulation of steroid hormone biosynthetic process Source: Ensembl
Protein autophosphorylation Source: UniProtKB
Regulation of JNK cascade Source: UniProtKB
Response to ethanol Source: Ensembl
Response to L-glutamate Source: Ensembl
Response to nicotine Source: Ensembl
Response to vitamin E Source: Ensembl
Signal transduction Source: ProtInc
Transcytosis Source: ARUK-UCL
Transmembrane receptor protein tyrosine kinase signaling pathway Source: GO_Central

Cell membrane

Insulin-like growth factor 1 resistance (IGF1RES):
A disorder characterized by intrauterine growth retardation, poor postnatal growth and increased plasma IGF1 levels.

Extracellular: 741-935
Helical: 936-959
Cytoplasmic: 960-1367

Autophosphorylated on tyrosine residues in response to ligand binding. Autophosphorylation occurs in trans, i.e. one subunit of the dimeric receptor phosphorylates tyrosine residues on the other subunit. Autophosphorylation occurs in a sequential manner; Tyr-1165 is predominantly phosphorylated first, followed by phosphorylation of Tyr-1161 and Tyr-1166. While every single phosphorylation increases kinase activity, all three tyrosine residues in the kinase activation loop (Tyr-1165, Tyr-1161 and Tyr-1166) have to be phosphorylated for optimal activity. Can be autophosphorylated at additional tyrosine residues (in vitro). Autophosphorylated is followed by phosphorylation of juxtamembrane tyrosines and C-terminal serines. Phosphorylation of Tyr-980 is required for IRS1- and SHC1-binding. Phosphorylation of Ser-1278 by GSK-3beta restrains kinase activity and promotes cell surface expression, it requires a priming phosphorylation at Ser-1282. Dephosphorylated by PTPN1 (By similarity).By similarity
Polyubiquitinated at Lys-1168 and Lys-1171 through both 'Lys-48' and 'Lys-29' linkages, promoting receptor endocytosis and subsequent degradation by the proteasome. Ubiquitination is facilitated by pre-existing phosphorylation.
Sumoylated with SUMO1.
Controlled by regulated intramembrane proteolysis (RIP). Undergoes metalloprotease-dependent constitutive ectodomain shedding to produce a membrane-anchored 52 kDa C-Terminal fragment which is further processed by presenilin gamma-secretase to yield an intracellular 50 kDa fragment.