TY - JOUR
T1 - Ligand-independent dimerization of oncogenic v-erbB products involves covalent interactions
AU - Adelsman, Margaret A.
AU - Huntley, Brenda K.
AU - Maihle, Nita J.
PY - 1996
Y1 - 1996
N2 - Mutant v-erbB products of avian c-erbB1 have previously been used to correlate structural domains of the receptor encoded by this proto-oncogene with tissue-specific transformation potential. In these studies, deletion of the ligand-binding domain of the receptor has been shown to be required for transformation of erythroblasts, fibroblasts, and endothelial cells. It has, therefore, been postulated that deletion of this domain results in an allosteric change in the receptor analogous to the ligand-bound state of the epidermal growth factor receptor; i.e., it induces a receptor conformation that is constitutively active with respect to mitogenic signaling. While oncogenic v-erbB products have been shown to be expressed on the cell surface of both fibroblasts and erythroblasts, no comprehensive analysis of the oligomeric potential of these products has been conducted. Since the first event known to follow epidermal growth factor binding to its receptor is oligomerization, and receptor dimerization has been correlated with mitogenic signaling, we have carefully analyzed the ability of several v-erbB products to oligomerize in the three target cell types transformed by these oncogenes. In this report, we demonstrate that v-erbB products can efficiently homodimerize in all three target tissues, that this dimerization is ligand independent and occurs at the cell surface, and that there is no apparent correlation between v-erbB dimerization and transformation of avian fibroblasts. Furthermore, both oncogenic and non-oncogenic v-erbB products can heterodimerize with the native c-erbB1 product in chicken embryo fibroblasts, suggesting that heterodimerization between v-erbB and native c- erbB1 is not sufficient to result in c-erbB1-mediated sarcomagenesis.
AB - Mutant v-erbB products of avian c-erbB1 have previously been used to correlate structural domains of the receptor encoded by this proto-oncogene with tissue-specific transformation potential. In these studies, deletion of the ligand-binding domain of the receptor has been shown to be required for transformation of erythroblasts, fibroblasts, and endothelial cells. It has, therefore, been postulated that deletion of this domain results in an allosteric change in the receptor analogous to the ligand-bound state of the epidermal growth factor receptor; i.e., it induces a receptor conformation that is constitutively active with respect to mitogenic signaling. While oncogenic v-erbB products have been shown to be expressed on the cell surface of both fibroblasts and erythroblasts, no comprehensive analysis of the oligomeric potential of these products has been conducted. Since the first event known to follow epidermal growth factor binding to its receptor is oligomerization, and receptor dimerization has been correlated with mitogenic signaling, we have carefully analyzed the ability of several v-erbB products to oligomerize in the three target cell types transformed by these oncogenes. In this report, we demonstrate that v-erbB products can efficiently homodimerize in all three target tissues, that this dimerization is ligand independent and occurs at the cell surface, and that there is no apparent correlation between v-erbB dimerization and transformation of avian fibroblasts. Furthermore, both oncogenic and non-oncogenic v-erbB products can heterodimerize with the native c-erbB1 product in chicken embryo fibroblasts, suggesting that heterodimerization between v-erbB and native c- erbB1 is not sufficient to result in c-erbB1-mediated sarcomagenesis.
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U2 - 10.1128/jvi.70.4.2533-2544.1996
DO - 10.1128/jvi.70.4.2533-2544.1996
M3 - Article
C2 - 8642683
AN - SCOPUS:0029922880
SN - 0022-538X
VL - 70
SP - 2533
EP - 2544
JO - Journal of Virology
JF - Journal of Virology
IS - 4
ER -