Epidermal growth factor receptor distribution during chemotactic responses.
To determine the distribution of the epidermal growth factor (EGF) receptor (EGFR) on the surface of cells responding to EGF as a chemoattractant, an EGFR-green fluorescent protein chimera was expressed in the MTLn3 mammary carcinoma cell line. The chimera was functional and easily visualized on the cell surface. In contrast to other studies indicating that the EGFR might be localized to certain regions of the plasma membrane, we found that the chimera is homogeneously distributed on the plasma membrane and becomes most concentrated in vesicles after endocytosis. In spatial gradients of EGF, endocytosed receptor accumulates on the upgradient side of the cell. Visualization of the binding of fluorescent EGF to cells reveals that the affinity properties of the receptor, together with its expression level on cells, can provide an initial amplification step in spatial gradient sensing.
Bailly
M
M
Department of Anatomy, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
Wyckoff
J
J
Bouzahzah
B
B
Hammerman
R
R
Sylvestre
V
V
Cammer
M
M
Pestell
R
R
Segall
J E
JE
D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D016764:Cell Polarity; D002633:Chemotaxis / Q000502:physiology*; D004815:Epidermal Growth Factor / Q000378:metabolism / Q000494:pharmacology; D066246:ErbB Receptors / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D051381:Rats; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D022161:Transport Vesicles / Q000378:metabolism; D014407:Tumor Cells, Cultured
D008164:Luminescent Proteins; D011994:Recombinant Proteins; D049452:Green Fluorescent Proteins; D004815:Epidermal Growth Factor; D066246:ErbB Receptors