Activation of the EGF receptor in A431 cells induces the hydrolysis of phosphoinositides and a transient rise of the cytosolic Ca2+ concentration, [Ca2+]i, which are completely inhibited by acute pretreatment with activators of protein kinase C, such as phorbol esters. Down regulation of the enzyme (by long-term pretreatment of the cells with phorbol esters) causes the [Ca2+]i response to EGF to increase in magnitude and, especially, to become much more persistent (average t1/2 of [Ca2+]i decline 9 min with respect to 2.3 min in controls). These results demonstrate that the activation of protein kinase C induced by EGF in intact A431 cells is sufficient to trigger a feed back, autolimitative regulation of the EGF receptor that might play a prominent physiological role in the definition of the mitogenic activity of the growth factor.
Protein kinase C-mediated feed back inhibition of the Ca2+ response at the EGF receptor / A. Pandiella, L. M. Vicentini, J. Meldolesi. - In: BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS. - ISSN 0006-291X. - 149:1(1987 Nov 30), pp. 145-151.
Protein kinase C-mediated feed back inhibition of the Ca2+ response at the EGF receptor
L. M. VicentiniSecondo
;
1987
Abstract
Activation of the EGF receptor in A431 cells induces the hydrolysis of phosphoinositides and a transient rise of the cytosolic Ca2+ concentration, [Ca2+]i, which are completely inhibited by acute pretreatment with activators of protein kinase C, such as phorbol esters. Down regulation of the enzyme (by long-term pretreatment of the cells with phorbol esters) causes the [Ca2+]i response to EGF to increase in magnitude and, especially, to become much more persistent (average t1/2 of [Ca2+]i decline 9 min with respect to 2.3 min in controls). These results demonstrate that the activation of protein kinase C induced by EGF in intact A431 cells is sufficient to trigger a feed back, autolimitative regulation of the EGF receptor that might play a prominent physiological role in the definition of the mitogenic activity of the growth factor.Pubblicazioni consigliate
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