[The direct demonstration of the tyrosine phosphorylation of epidermal growth factor receptors internalized in the endosomes of A431 cells].
Phosphorylation of the epidermal growth factor (EGF) receptors in endosomes isolated from A431 cells was studied using antiphosphotyrosin antibody (anti-P-Tyr). A431 cells were preincubated with EGF and then washed with acid buffer to remove surface-bound EGF. Endosomes were isolated from such cells by the method of subcellular fractionation on Percoll density gradient. Addition to isolated endosomes of anti-P-Tyr complexes with immunogold resulted in a significant shift of endosome peak to the high density region. This fact indicates that anti-P-Tyr interacts with phosphotyrosine residues of EGF receptors localized in endosomes.
Nesterov
A M
AM
Vdovina
I B
IB
Kornilova
E S
ES
Nikol'skiĭ
N N
NN
D000906:Antibodies / Q000302:isolation & purification; D002294:Carcinoma, Squamous Cell / Q000276:immunology / Q000378:metabolism*; D002458:Cell Fractionation / Q000379:methods; D002460:Cell Line; D004815:Epidermal Growth Factor; D066246:ErbB Receptors / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D015388:Organelles / Q000276:immunology / Q000378:metabolism*; D010766:Phosphorylation; D019000:Phosphotyrosine; D014407:Tumor Cells, Cultured / Q000276:immunology / Q000378:metabolism; D014443:Tyrosine / Q000031:analogs & derivatives / Q000276:immunology / Q000378:metabolism*
D000906:Antibodies; D019000:Phosphotyrosine; D014443:Tyrosine; D004815:Epidermal Growth Factor; D066246:ErbB Receptors
Priamoe dokazatel'stvo fosforilirovaniia po tirozinu retseptorov épidermal'nogo faktora rosta, internalizovannykh v éndosomakh kletok A431.