The following brief summary is based on a recent review by Rubin and Baserga w1x, and the reader is referred to that review for extended references. A simplified representation of the IGF system includes 3 receptors, 3 ligands and 6 IGF binding proteins .IGFBPs.. The ligands are the mature IGF-I.70 aminoacids., the mature IGF-II.67 aminoacids. and insulin. The receptors are the type I insulin-like growth factor receptor.IGF-IR., the insulin receptor .IR. and the IGF-II receptor .IGF-IIR.. In terms of cellular proliferation, the IGF-IR is the most active of the 3 receptors.see below.: it is activated by all 3 ligands, and, although it has several functional features in common with the IR w2x, the b subunit of the IGF-IR is 10 times more mitogenic than the beta subunit of the IR w3x. Insulin at supraphysiological concentrations also activates the IGF-IR; this is an important point to remember, because when insulin is used at mg concentrations, it exerts its mitogenic stimulation through the IGF-IR w4x. Under appropriate conditions, the IR is mitogenic.
The IGF-I receptor in cell growth, transformation and apoptosis
RUBINI, Michele;
1997
Abstract
The following brief summary is based on a recent review by Rubin and Baserga w1x, and the reader is referred to that review for extended references. A simplified representation of the IGF system includes 3 receptors, 3 ligands and 6 IGF binding proteins .IGFBPs.. The ligands are the mature IGF-I.70 aminoacids., the mature IGF-II.67 aminoacids. and insulin. The receptors are the type I insulin-like growth factor receptor.IGF-IR., the insulin receptor .IR. and the IGF-II receptor .IGF-IIR.. In terms of cellular proliferation, the IGF-IR is the most active of the 3 receptors.see below.: it is activated by all 3 ligands, and, although it has several functional features in common with the IR w2x, the b subunit of the IGF-IR is 10 times more mitogenic than the beta subunit of the IR w3x. Insulin at supraphysiological concentrations also activates the IGF-IR; this is an important point to remember, because when insulin is used at mg concentrations, it exerts its mitogenic stimulation through the IGF-IR w4x. Under appropriate conditions, the IR is mitogenic.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
