[The correlation between epidermal growth factor (EGF) binding with receptors and the tyrosine phosphorylation of the EGF receptors in the plasma membrane and in the endosomes].
The ratio of tyrosine-phosphorylated EGF-receptors was estimated for surface and endosomal EGF-receptor complexes on A431 cells. The cells were incubated with 125I-EGF, and then 125I-EGF was covalently bound to the receptor by cross-linking reagent-suberate. Following the cell lysis, the tyrosine-phosphorylated receptors were immunoprecipitated by polyclonal antiphosphotyrosine antibody. The ratio between the whole pool of 125I-EGF-linked and tyrosine-phosphorylated receptors were determined by densitometry of gels. It is found that only 20-45% of EGF-linked receptors are tyrosine-phosphorylated. The same share of tyrosine-phosphorylation was found for internalized EGF-receptor complexes.
Vdovina
I B
IB
Burova
E B
EB
Nesterov
A M
AM
Nikol'skiĭ
N N
NN
D002294:Carcinoma, Squamous Cell / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D011992:Endosomes / Q000378:metabolism*; D004815:Epidermal Growth Factor / Q000378:metabolism*; D066246:ErbB Receptors / Q000378:metabolism*; D006801:Humans; D007457:Iodine Radioisotopes; D008024:Ligands; D008565:Membrane Proteins / Q000378:metabolism*; D010766:Phosphorylation; D011233:Precipitin Tests; D011485:Protein Binding; D014407:Tumor Cells, Cultured; D014443:Tyrosine / Q000378:metabolism*
D007457:Iodine Radioisotopes; D008024:Ligands; D008565:Membrane Proteins; D014443:Tyrosine; D004815:Epidermal Growth Factor; D066246:ErbB Receptors