Abstract
The localization of epidermal growth factor (EGF) receptors over the plasma membranes of human epidermoid carcinoma A431 cells was analyzed at the electron microscopic level using surface replica techniques and conventional thin sections, in combination with immunocytochemistry. Immunolabeling was performed using two distinct monoclonal antibodies directed against the extracellular portion of the receptor, followed by protein A-colloidal gold conjugates. Unexpectedly, with the first monoclonal antibody used, the distribution of the receptors in both unfixed and glutaraldehyde-fixed cells was clearly regionalized, showing a preferential localization of the immunolabeling at the cell periphery as well as over the areas rich in microvilli and in coated and uncoated pits. A similar pattern of distribution was observed also with the other monoclonal antibody, but only when the cells were fixed with glutaraldehyde before immunolabeling. Treatment with the phorbol ester 12-O-tetradecanoylphorbol-13-acetate modifies this distribution, inducing a more disperse pattern. Our observations suggest that a minor group of EGF receptors, which may represent the high-affinity receptors, presents a regional distribution, similar to that described for typical recycling receptors.
| Original language | English |
|---|---|
| Pages (from-to) | 326-333 |
| Number of pages | 8 |
| Journal | Experimental Cell Research |
| Volume | 175 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - 1988 |
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Nonrandom distribution of epidermal growth factor receptors on the plasma membrane of human A431 cells. / Torrisi, Maria Rosaria; Pavan, Antonio; Lotti, Lavinia Vittoria; Zompetta, Claudia; Faggioni, Alberto; Frati, Luigi.
In: Experimental Cell Research, Vol. 175, No. 2, 1988, p. 326-333.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Nonrandom distribution of epidermal growth factor receptors on the plasma membrane of human A431 cells
AU - Torrisi, Maria Rosaria
AU - Pavan, Antonio
AU - Lotti, Lavinia Vittoria
AU - Zompetta, Claudia
AU - Faggioni, Alberto
AU - Frati, Luigi
PY - 1988
Y1 - 1988
N2 - The localization of epidermal growth factor (EGF) receptors over the plasma membranes of human epidermoid carcinoma A431 cells was analyzed at the electron microscopic level using surface replica techniques and conventional thin sections, in combination with immunocytochemistry. Immunolabeling was performed using two distinct monoclonal antibodies directed against the extracellular portion of the receptor, followed by protein A-colloidal gold conjugates. Unexpectedly, with the first monoclonal antibody used, the distribution of the receptors in both unfixed and glutaraldehyde-fixed cells was clearly regionalized, showing a preferential localization of the immunolabeling at the cell periphery as well as over the areas rich in microvilli and in coated and uncoated pits. A similar pattern of distribution was observed also with the other monoclonal antibody, but only when the cells were fixed with glutaraldehyde before immunolabeling. Treatment with the phorbol ester 12-O-tetradecanoylphorbol-13-acetate modifies this distribution, inducing a more disperse pattern. Our observations suggest that a minor group of EGF receptors, which may represent the high-affinity receptors, presents a regional distribution, similar to that described for typical recycling receptors.
AB - The localization of epidermal growth factor (EGF) receptors over the plasma membranes of human epidermoid carcinoma A431 cells was analyzed at the electron microscopic level using surface replica techniques and conventional thin sections, in combination with immunocytochemistry. Immunolabeling was performed using two distinct monoclonal antibodies directed against the extracellular portion of the receptor, followed by protein A-colloidal gold conjugates. Unexpectedly, with the first monoclonal antibody used, the distribution of the receptors in both unfixed and glutaraldehyde-fixed cells was clearly regionalized, showing a preferential localization of the immunolabeling at the cell periphery as well as over the areas rich in microvilli and in coated and uncoated pits. A similar pattern of distribution was observed also with the other monoclonal antibody, but only when the cells were fixed with glutaraldehyde before immunolabeling. Treatment with the phorbol ester 12-O-tetradecanoylphorbol-13-acetate modifies this distribution, inducing a more disperse pattern. Our observations suggest that a minor group of EGF receptors, which may represent the high-affinity receptors, presents a regional distribution, similar to that described for typical recycling receptors.
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U2 - 10.1016/0014-4827(88)90196-6
DO - 10.1016/0014-4827(88)90196-6
M3 - Article
C2 - 3360057
AN - SCOPUS:0023951536
VL - 175
SP - 326
EP - 333
JO - Experimental Cell Research
JF - Experimental Cell Research
SN - 0014-4827
IS - 2
ER -