Interaction of epidermal growth factor with receptors on human and porcine thyroid membranes

1984 ◽  
Vol 102 (1) ◽  
pp. 57-61 ◽  
Author(s):  
H. Humphries ◽  
S. MacNeil ◽  
D. S. Munro ◽  
S. Tomlinson
Keyword(s):  
Enzyme Activity ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Binding Sites ◽  
Affinity Constant ◽  
Maximal Inhibition ◽  
High Affinity ◽  
Epidermal Growth ◽  
And Function ◽  
Bovine Tsh

ABSTRACT Recent evidence suggests that epidermal growth factor (EGF) may play an important role in the regulation of thyroid growth and function. We have examined the interaction of murine EGF (mEGF) with human and porcine thyroid membranes and compared this with the binding of bovine TSH (bTSH) using 125I-labelled hormones as tracers. The characteristics of the binding of mEGF were found to be similar for human and porcine thyroid membranes. Epidermal growth factor bound with high affinity (affinity constant = 1·4 × 109 l/mol); the density of binding sites was low compared with the TSH receptor. At 37 °C, the binding of 125I-labelled EGF was maximal at 1 h and was saturable in the presence of unlabelled EGF; half-maximal inhibition was at 1 ng EGF/tube (0·5 nmol/l) using 0·5 mg membrane protein/tube. Unlabelled bTSH had no effect on the binding of labelled EGF. Similarly, unlabelled EGF did not affect the binding of labelled TSH; hence it was concluded that mEGF and bTSH bound to independent sites. Epidermal growth factor had no effect on adenylate cyclase activity in membranes prepared from human non-toxic goitre; increasing concentrations of EGF did not affect basal, TSH-stimulated or fluoride-stimulated enzyme activity. J. Endocr. (1984) 102, 57–61

Ontogeny and characterization of epidermal growth factor receptors on the fetal area of the sheep placenta

1993 ◽  
Vol 136 (1) ◽  
pp. 43-50 ◽  
Author(s):  
M. C. Lacroix ◽  
G. Kann
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Binding Sites ◽  
Dissociation Constants ◽  
Egf Receptors ◽  
High Affinity ◽  
Reducing Conditions ◽  
Sds Page ◽  
Ovine Placenta ◽  
Epidermal Growth

ABSTRACT Studies of the binding of 125I-labelled epidermal growth factor (EGF) to the ovine placenta were carried out on days 50, 90–100 and 140 of pregnancy. Membrane fractions were purified from the fetal area of the cotyledon. Two classes of binding sites were found. Their dissociation constants (Kd) were not significantly different for the three stages of pregnancy considered (high-affinity Kd 54–70·2 pmol/l; low-affinity Kd 12·2 to 19 nmol/l). However, the number of high-affinity binding sites on days 90–100 was significantly (P < 0·01) greater (146 ± 19 fmol/mg protein) than on either day 50 or day 140 (respectively 74·2 ± 1·26 and 56·3 ± 5·6 fmol/mg protein). Affinity cross-linking studies followed by SDS-PAGE under reducing conditions demonstrated that the major part of the EGF was specifically cross-linked to a protein of molecular weight of 150 kDa and to lesser extent to 180 kDa and 130 kDa proteins. Membranes prepared from unfrozen tissues, in the presence of sodium iodoacetate to reduce endogenous enzymatic conversion of the 180 kDa form to the 150 and 130 kDa forms, still exhibited a major EGF-binding protein of 150 kDa. The occurrence of an increased number of EGF receptors at the period of rapid cotyledonary growth which coincides with the increase in placental hormonal secretions suggests that EGF has a role in the development of the ovine placenta. Journal of Endocrinology (1993) 136, 43–50

scholarly journals Cross talk among tyrosine kinase receptors in PC12 cells: desensitization of mitogenic epidermal growth factor receptors by the neurotrophic factors, nerve growth factor and basic fibroblast growth factor.

1993 ◽  
Vol 4 (7) ◽  
pp. 737-746 ◽  
Author(s):  
I Mothe ◽  
R Ballotti ◽  
S Tartare ◽  
A Kowalski-Chauvel ◽  
E Van Obberghen
Keyword(s):  
Nerve Growth Factor ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Fibroblast Growth Factor ◽  
Pc12 Cells ◽  
Binding Sites ◽  
Egf Receptor ◽  
Fibroblast Growth ◽  
High Affinity ◽  
Epidermal Growth

We have studied the effects of nerve growth factor (NGF) and basic fibroblast growth factor (bFGF) on epidermal growth factor (EGF) binding to PC12 cells. We show that NGF and bFGF rapidly induce a reduction in 125I-EGF binding to PC12 cells in a dose-dependent manner. This decrease amounts to 50% for NGF and 35% for bFGF. Both factors appear to act through a protein kinase C(PKC)-independent pathway, because their effect persists in PKC-downregulated PC12 cells. Scatchard analysis indicates that NGF and bFGF decrease the number of high affinity EGF binding sites. In addition to their effect on EGF binding, NGF and bFGF activate in intact PC12 cells one or several serine/threonine kinases leading to EGF receptor threonine phosphorylation. Using an in vitro phosphorylation system, we show that NGF- or bFGF-activated extracellular regulated kinase 1 (ERK1) is able to phosphorylate a kinase-deficient EGF receptor. Phosphoamino acid analysis indicates that this phosphorylation occurs mainly on threonine residues. Furthermore, two comparable phosphopeptides are observed in the EGF receptor, phosphorylated either in vivo after NGF treatment or in a cell-free system by NGF-activated ERK1. Finally, a good correlation was found between the time courses of ERK1 activation and 125I-EGF binding inhibition after NGF or bFGF treatment. In conclusion, in PC12 cells the NGF- and bFGF-stimulated ERK1 appears to be involved in the induction of the threonine phosphorylation of the EGF receptor and the decrease in the number of high affinity EGF binding sites.

scholarly journals Transforming growth factor-beta modulates the high-affinity receptors for epidermal growth factor and transforming growth factor-alpha.

1985 ◽  
Vol 100 (5) ◽  
pp. 1508-1514 ◽  
Author(s):  
J Massagué
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Affinity Labeling ◽  
Tgf Beta ◽  
Semisolid Medium ◽  
High Affinity ◽  
Receptor Structure ◽  
Epidermal Growth

The epidermal growth factor (EGF) receptor mediates the induction of a transformed phenotype in normal rat kidney (NRK) cells by transforming growth factors (TGFs). The ability of EGF and its analogue TGF-alpha to induce the transformed phenotype in NRK cells is greatly potentiated by TGF-beta, a polypeptide that does not interact directly with binding sites for EGF or TGF-alpha. Our evidence indicates that TGF-beta purified from retrovirally transformed rat embryo cells and human platelets induces a rapid (t 1/2 = 0.3 h) decrease in the binding of EGF and TGF-alpha to high-affinity cell surface receptors in NRK cells. No change due to TGF-beta was observed in the binding of EGF or TGF-alpha to lower affinity sites also present in NRK cells. The effect of TGF-beta on EGF/TGF-alpha receptors was observed at concentrations (0.5-20 pM) similar to those at which TGF-beta is active in promoting proliferation of NRK cells in monolayer culture and semisolid medium. Affinity labeling of NRK cells and membranes by cross-linking with receptor-bound 125I-TGF-alpha and 125I-EGF indicated that both factors interact with a common 170-kD receptor structure. Treatment of cells with TGF-beta decreased the intensity of affinity-labeling of this receptor structure. These data suggest that the 170 kD high-affinity receptors for EGF and TGF-alpha in NRK cells are a target for rapid modulation by TGF-beta.

Membrane vesicles of A431 cells contain one class of epidermal growth factor binding sites

1990 ◽  
Vol 1052 (3) ◽  
pp. 453-460 ◽  
Author(s):  
Jos A.M. Berkers ◽  
Paul M.P. van Bergen en Henegouwen ◽  
Arie J. Verkleij ◽  
Johannes Boonstra
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Binding Sites ◽  
Membrane Vesicles ◽  
A431 Cells ◽  
Factor Binding ◽  
Epidermal Growth
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