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| align="center" colspan="2" |
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| colspan="2" bgcolor="#dddddd" | Identifiers
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| bgcolor="#e7dcc3" | Symbol(s)
| bgcolor="#eeeeee" | [IGF1R]
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| bgcolor="#e7dcc3" | Entrez
| bgcolor="#eeeeee" | [3480]
|- class="hiddenStructure"
| bgcolor="#e7dcc3" | OMIM
| bgcolor="#eeeeee" | [147370]
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| bgcolor="#e7dcc3" | RefSeq
| bgcolor="#eeeeee" | [NM_000875]
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| bgcolor="#e7dcc3" | UniProt
| bgcolor="#eeeeee" | [P08069]
|- class="hiddenStructure"
| bgcolor="#e7dcc3" | PDB
| bgcolor="#eeeeee" | []
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| colspan="2" bgcolor="#dddddd" | Other data
|- class="hiddenStructure"
| bgcolor="#e7dcc3" | EC number
| bgcolor="#eeeeee" | []
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| bgcolor="#e7dcc3" | Locus
| bgcolor="#eeeeee" | Chr. 15[q26.3]
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|}
The Insulin-like Growth Factor 1 (IGF-1) Receptor is a transmembranereceptor that is activated by IGF-1 and by the related growth factor IGF-II. It belongs to the large class of tyrosine kinase receptors. This receptor mediates the effects of IGF-1, which is a polypeptide protein hormone similar in molecular structure to insulin. IGF-1 plays an important role in growth and continues to have anabolic effects in adults - meaning that it can induce hypertrophy of skeletal muscle and other target tissues.
Two alpha subunits and two beta subunits make up the IGF-1 receptor. The beta subunits pass through the cellular membrane and are linked by disulfide bonds.
Receptor Family
Tyrosine kinase receptors, including, the IGF-1 receptor, mediate their activity by causing the addition of a phosphate groups to particular tyrosines on certain proteins within a cell. This addition of phosphate induces what are caled "cell signaling" cascades - and the usual result of activation of the IGF-1 receptor is survival and proliferation in mitosis-competent cells, and growth (hypertrophy) in tissues such as skeletal muscle and cardiac muscle.
IGF-1 vs Insulin Receptor Signaling
IGF-1 binds to at least two cell surface receptors: the IGF1 Receptor (IGFR), and the insulin receptor. The IGF-1 receptor seems to be the "physiologic" receptor - it binds IGF-1 at significantly higher affinity than it binds the insulin receptor. Like the insulin receptor, the IGF-1 receptor is a receptor tyrosine kinase - meaning it signals by causing the addition of a phosphate molecule on particular tyrosines. IGF-1 activates the Insulin receptor at approximately 0.1x the potency of insulin. Part of this signaling may be via IGF1R-InsulinReceptor heterodimers (the reason for the confusion is that binding studies show that IGF1 binds the insulin receptor 100-fold less well than insulin, yet that does not correlate with the actual potency of IGF1 in vivo at inducing phosphorylation of the Insulin receptor, and hypoglycemia).
