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From Proteopedia
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== Function == | == Function == | ||
[[http://www.uniprot.org/uniprot/IGF1R_HUMAN IGF1R_HUMAN]] 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.<ref>PMID:8257688</ref> <ref>PMID:1846292</ref> <ref>PMID:8452530</ref> <ref>PMID:7679099</ref> <ref>PMID:10579905</ref> <ref>PMID:10747872</ref> <ref>PMID:12138094</ref> <ref>PMID:12556535</ref> <ref>PMID:16831875</ref> 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.<ref>PMID:8257688</ref> <ref>PMID:1846292</ref> <ref>PMID:8452530</ref> <ref>PMID:7679099</ref> <ref>PMID:10579905</ref> <ref>PMID:10747872</ref> <ref>PMID:12138094</ref> <ref>PMID:12556535</ref> <ref>PMID:16831875</ref> [[http://www.uniprot.org/uniprot/INS_HUMAN INS_HUMAN]] Insulin decreases blood glucose concentration. It increases cell permeability to monosaccharides, amino acids and fatty acids. It accelerates glycolysis, the pentose phosphate cycle, and glycogen synthesis in liver. | [[http://www.uniprot.org/uniprot/IGF1R_HUMAN IGF1R_HUMAN]] 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.<ref>PMID:8257688</ref> <ref>PMID:1846292</ref> <ref>PMID:8452530</ref> <ref>PMID:7679099</ref> <ref>PMID:10579905</ref> <ref>PMID:10747872</ref> <ref>PMID:12138094</ref> <ref>PMID:12556535</ref> <ref>PMID:16831875</ref> 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.<ref>PMID:8257688</ref> <ref>PMID:1846292</ref> <ref>PMID:8452530</ref> <ref>PMID:7679099</ref> <ref>PMID:10579905</ref> <ref>PMID:10747872</ref> <ref>PMID:12138094</ref> <ref>PMID:12556535</ref> <ref>PMID:16831875</ref> [[http://www.uniprot.org/uniprot/INS_HUMAN INS_HUMAN]] Insulin decreases blood glucose concentration. It increases cell permeability to monosaccharides, amino acids and fatty acids. It accelerates glycolysis, the pentose phosphate cycle, and glycogen synthesis in liver. | ||
| + | <div style="background-color:#fffaf0;"> | ||
| + | == Publication Abstract from PubMed == | ||
| + | Tyrosine kinase receptor of insulin-like growth factor 1 receptor (IGF-1R) and insulin receptor (IR) bind to hormones, such as insulin, IGF-1, and IGF-2, and transduces the signals across the cell membrane. However, the complete structure of the receptor and the signal transduction mechanism remains unclear. Here, we report the cryo-EM structure of the ligand-bound ectodomain in the full-length human IGF-1R. We reconstructed the IGF-1R/insulin complex at 4.7 A and the IGF-1R/IGF-1 complex at 7.7 A. Our structures reveal that only one insulin or one IGF-1 molecule binds to and activates the full-length human IGF-1R receptor. | ||
| + | |||
| + | Visualization of Ligand-Bound Ectodomain Assembly in the Full-Length Human IGF-1 Receptor by Cryo-EM Single-Particle Analysis.,Zhang X, Yu D, Sun J, Wu Y, Gong J, Li X, Liu L, Liu S, Liu J, Wu Y, Li D, Ma Y, Han X, Zhu Y, Wu Z, Wang Y, Ouyang Q, Wang T Structure. 2020 Apr 1. pii: S0969-2126(20)30079-4. doi:, 10.1016/j.str.2020.03.007. PMID:32275863<ref>PMID:32275863</ref> | ||
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| + | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | ||
| + | </div> | ||
| + | <div class="pdbe-citations 6jk8" style="background-color:#fffaf0;"></div> | ||
==See Also== | ==See Also== | ||
Revision as of 06:00, 22 April 2020
Cryo-EM structure of the full-length human IGF-1R in complex with insulin
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