Binding properties of chimeric insulin receptors containing the cysteine-rich domain of either the insulin-like growth factor I receptor or the insulin receptor related receptor

Biochemistry ◽  
1991 ◽  
Vol 30 (21) ◽  
pp. 5113-5117 ◽  
Author(s):  
Bei Zhang ◽  
Richard A. Roth
Keyword(s):  
Growth Factor ◽  
Insulin Receptor ◽  
Insulin Receptors ◽  
Insulin Like Growth Factor ◽  
Binding Properties ◽  
Factor I ◽  
Rich Domain ◽  
Growth Factor I ◽  
Cysteine Rich Domain

scholarly journals Immunological relationships between receptors for insulin and insulin-like growth factor I. Evidence for structural heterogeneity of insulin-like growth factor I receptors involving hybrids with insulin receptors

1989 ◽  
Vol 263 (2) ◽  
pp. 553-563 ◽  
Author(s):  
M A Soos ◽  
K Siddle
Keyword(s):  
Growth Factor ◽  
Insulin Receptor ◽  
Insulin Receptors ◽  
Insulin Like Growth Factor ◽  
Intact Cells ◽  
Receptor Complexes ◽  
Factor I ◽  
Igf I ◽  
Alpha Beta ◽  
Growth Factor I

The receptors for insulin and insulin-like growth factor-I (IGF-I) are closely related in primary sequence and overall structure. We have examined the immunological relationships between these receptors by testing the reactivity of anti-(insulin receptor) monoclonal antibodies with IGF-I receptors in various tissues and cell lines. Antibodies for six distinct epitopes reacted with a subfraction of IGF-I receptors, as shown by inhibition of 125I-IGF-I binding, precipitation of 125I-IGF-I-receptor complexes or immunodepletion of receptor from tissue extracts before binding assays. Both immunoreactive and non-immunoreactive subfractions displayed the expected properties of ‘classical’ IGF-I receptors, in terms of relative affinities for IGF-I and insulin. The proportion of total IGF-I receptors which was immunoreactive varied in different cell types, being approx. 40% in Hep G2 cells, 35-40% in placental membranes and 75-85% in IM-9 cells. The immunoreactive fraction was somewhat higher in solubilized receptors than in the corresponding intact cells or membranes. A previously described monoclonal antibody, alpha-IR-3, specific for IGF-I receptors, inhibited IGF-I binding by more than 80% in all preparations. When solubilized placental receptors were pretreated with dithiothreitol (DTT) under conditions reported to reduce intramolecular (class I) disulphide bonds, the immunoreactivity of IGF-I receptors was abolished although total IGF-I binding was little affected. Under the same conditions insulin receptors remained fully immunoreactive. When solubilized receptor preparations were fractionated by gel filtration, both IGF-I and insulin receptors ran as symmetrical peaks of identical mobility. After DTT treatment, the IGF-I receptor was partially converted to a lower molecular mass form which was not immunoreactive. The insulin receptor peak showed a much less pronounced skewing and remained fully immunoreactive in all fractions. It is concluded that the anti- (insulin receptor) antibodies do not react directly with IGF-I receptor polypeptide, and that the apparent immunoreactivity of a subfraction of IGF-I receptors reflects their physical association with insulin receptors, both in cell extracts and in intact cells. The most likely basis for this association appears to be a ‘hybrid’ receptor containing one half (alpha beta) of insulin receptor polypeptide and the other (alpha‘beta’) of IGF-I receptor polypeptide within the native (alpha beta beta‘alpha’) heterotetrameric structure.

scholarly journals Comparison of insulin-like growth factor I receptor and insulin receptor purified from human placental membranes.

1986 ◽  
Vol 261 (35) ◽  
pp. 16727-16731
Author(s):  
Y Fujita-Yamaguchi ◽  
T R LeBon ◽  
M Tsubokawa ◽  
W Henzel ◽  
S Kathuria ◽  
...  
Keyword(s):  
Growth Factor ◽  
Insulin Receptor ◽  
Insulin Like Growth Factor ◽  
Factor I ◽  
Placental Membranes ◽  
Growth Factor I

scholarly journals Interaction of Insulin Receptor Substrate-2 (IRS-2) with the Insulin and Insulin-like Growth Factor I Receptors

1996 ◽  
Vol 271 (20) ◽  
pp. 11641-11645 ◽  
Author(s):  
Weimin He ◽  
Ann Craparo ◽  
Youyan Zhu ◽  
Thomas J. O'Neill ◽  
Ling-Mei Wang ◽  
...  
Keyword(s):  
Growth Factor ◽  
Insulin Receptor ◽  
Insulin Receptor Substrate ◽  
Insulin Like Growth Factor ◽  
Factor I ◽  
Growth Factor I

scholarly journals Insulin/Insulin-like Growth Factor I Hybrid Receptors Have Different Biological Characteristics Depending on the Insulin Receptor Isoform Involved

2002 ◽  
Vol 277 (42) ◽  
pp. 39684-39695 ◽  
Author(s):  
Giuseppe Pandini ◽  
Francesco Frasca ◽  
Rossana Mineo ◽  
Laura Sciacca ◽  
Riccardo Vigneri ◽  
...  
Keyword(s):  
Growth Factor ◽  
Insulin Receptor ◽  
Biological Characteristics ◽  
Insulin Like Growth Factor ◽  
Factor I ◽  
Growth Factor I

scholarly journals Purified hybrid insulin/insulin-like growth factor-I receptors bind insulin-like growth factor-I, but not insulin, with high affinity

1993 ◽  
Vol 290 (2) ◽  
pp. 419-426 ◽  
Author(s):  
M A Soos ◽  
C E Field ◽  
K Siddle
Keyword(s):  
Monoclonal Antibody ◽  
Growth Factor ◽  
Insulin Receptors ◽  
Beta Subunit ◽  
Type I ◽  
Insulin Like Growth Factor ◽  
Factor I ◽  
Igf Receptors ◽  
Igf I ◽  
Growth Factor I

Hybrid insulin/insulin-like growth factor-I (IGF-I) receptors have previously been described in human placenta, but it has not been possible to study their properties in the presence of classical insulin receptors and type I IGF receptors. To facilitate the purification of hybrids, we produced an anti-peptide monoclonal antibody IGFR 1-2, directed against the C-terminal peptide of the type I IGF receptor beta-subunit. The antibody bound native human and rat type I IGF receptors, and reacted specifically with the beta-subunit on immunoblots. Solubilized placental microsomal membranes were depleted of classical type I IGF receptors by incubation with an immobilized monoclonal antibody IGFR 24-55, which reacts well with type I receptors but very poorly with hybrid receptors. Residual hybrid receptors were then isolated by incubation with immobilized antibody IGFR 1-2, and recovered by elution with excess of synthetic peptide antigen. Binding properties of hybrids were compared with those of immuno-affinity-purified insulin receptors and type I IGF receptors, by using the radioligands 125I-IGF-I and 125I-insulin. Hybrids bound approx. 20 times as much 125I-IGF-I as 125I-insulin at tracer concentrations (approx. 0.1 nM). The binding of 125I-insulin, but not 125I-IGF-I, to hybrids increased after treatment with dithiothreitol to reduce disulphide bonds between the alpha-subunits. Hybrids behaved very similarly to type I receptors with respect to the inhibition of 125I-IGF-I binding by unlabelled IGF-I and insulin. By contrast, the affinity of hybrids for insulin was approx. 10-fold lower than that of classical insulin receptors, as assessed by inhibition of 125I-insulin binding by unlabelled hormone. It is concluded that the properties of insulin receptors, but not IGF receptors, are markedly affected by assembly as hybrid compared with classical structures, and that hybrids are more likely to be responsive to IGF-I than insulin under physiological conditions.

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