The intrinsic protein-tyrosine kinase activity of the epidermal growth factor (EGF) receptor is required for signal transduction. Increased protein-tyrosine kinase activity is observed following the binding of EGF to the receptor. However, signaling is rapidly desensitized during EGF treatment. We report that EGF receptors isolated from desensitized cells exhibit a lower protein-tyrosine kinase...

We have tested the hypothesis that the mechanism of platelet-derived growth factor (PDGF) and phorbol diester action to decrease the apparent affinity of the epidermal growth factor (EGF) receptor is the phosphorylation of the EGF receptor at the Ca2+/phospholipid-dependent protein kinase (protein kinase C) phosphorylation site, threonine 654. Protein kinase C-deficient cells were prepared by p...

Stimulation of epidermal growth factor (EGF) receptor autophosphorylation by EGF and phosphorylation of a Mr 52,000 protein endogenous to the membrane extracts were decreased 6-12-fold in liver membrane extracts from mice homozygous for either the ob/ob or db/db mutation when compared to controls. Liver membranes from the mutant mice bound 4-5-fold less 125I-EGF/unit of protein than did their n...

Membrane components that interact with epidermal growth factor (EGF) and transforming growth factors (TGFs) have been identified by covalent crosslinking to their respective 125I-labeled ligands. Under appropriate conditions, disuccinimidyl suberate or hydroxysuccinimidyl p-azidobenzoate cross-link receptor-bound 125I-labeled EGF to a 140- to 170-kilodalton (kDal) receptor species in membranes ...

Southern blot-hybridization analysis of DNAs from human tumors demonstrated amplification of the epidermal growth fac tor (EGF) receptor gene in 10 of 12 squamous cell carcinoma cell lines tested and in none of 18 tumor cell lines of nonsquamous cell carcinomas. The degree of amplification in the squa mous cells varied from 2to 50-fold relative to the epidermal keratinocyte. Hybridization analy...

Thyroid cancer (TC) is the most prevalent malignant tumor in endocrine system. Serpin peptidase inhibitor clade E member 2 (SERPINE2) closely associated with metastasis. The aim of present study was to investigate whether SERPINE2 forms a feedback loop epidermal growth factor (EGF)/EGF receptor (EGFR) that regulates cellular processes human papillary thyroid carcinoma (TPC‑1) cells. Reverse tra...

Our recent studies have shown that proliferation of renal proximal tubular cells (RPTC) in the absence of growth factors requires activation of the epidermal growth factor (EGF) receptor. We sought to identify the endogenous EGF receptor ligand and investigate the mechanism(s) by which RPTC proliferate in different models. RPTC expressed both pro- and cleaved forms of heparin-binding epidermal ...

Here, we report the discovery of first plant-derived and noncanonical epidermal growth factor receptor (EGFR) agonist, 36-residue bleogen pB1 from Pereskia bleo Cactaceae family. We show that is a low-affinity EGFR agonist using suite chemical, biochemical, cellular, animal experiments which include incisor eruption wound-healing mouse models. A focused positional scanning library Ala- d-amino ...

Differing spatial scales of signaling cascades are critical for cell orientation during chemotactic responses. We used biotin EGF bound to streptavidin-coupled magnetic beads to locally stimulate cells overexpressing the EGF receptor. We have found that EGF-induced actin polymerization remains localized even under conditions of receptor overexpression. Conversely, EGF-induced ERK activation spr...

Heterologous regulation of the epidermal growth factor (EGF) receptor by platelet-derived growth factor (PDGF) was studied in FS4 human skin fibroblasts. The addition of PDGF to FS4 cells inhibited high affinity binding of 125I-EGF and stimulated phosphorylation of the EGF receptor. Phosphopeptide analysis by high performance liquid chromatography revealed that PDGF treatment of cells increased...