EXPRESSION OF C-ERBB-2 PROTO-ONCOGENE-ENCODED PROTEIN (P185(ERBB-2)) IN FUNCTIONAL-RAT AMELOBLASTS

The c-erbB-2 proto-oncogene encodes a transmembrane glycoprotein with tyrosine kinase activity, p185(erbB-2), that has been previously local ized in some developing and mature epithelia. The possible occurrence of p185 in the inner enamel epithelium of rat tooth germ was here inve stigated immunocytochemically. Postmitotic functional ameloblasts disp layed intense p185-immunoreactivity, thus suggesting that c-erbB-2 pro to-oncogene is active during odontogenesis. The expression of this gen e in differentiated and functional cells of the enamel organ suggests that its role is not restricted to mitotic events but may also be impo rtant in signalling pathways related to other cell activities.