Premium
Fibroblast growth factor receptors 1 and 2 are differentially regulated in murine embryonal carcinoma cells and in response to fibroblast growth factor‐4
Author(s) -
Ali Jahanara,
Mansukhani Alka,
Basilico Claudio
Publication year - 1995
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.1041650225
Subject(s) - fibroblast growth factor receptor , fibroblast growth factor , downregulation and upregulation , transfection , biology , fibroblast growth factor receptor 2 , fibroblast growth factor receptor 4 , fibroblast growth factor receptor 3 , microbiology and biotechnology , messenger rna , receptor , fibroblast , gene expression , fibroblast growth factor receptor 1 , cell culture , gene , biochemistry , genetics
We have studied the expression of two of the receptors for fibroblast growth factors, FGFR‐1 and FGFR‐2, in response to ligand binding and in embryonal carcinoma (EC cells)> Exposure of mouse fibroblasts to FGF‐4 or FGF‐2 results in a drastic downregulation of the mRNA levels for FGFR‐2, while expression of FGER‐1 mRNA appears unaffected. Furthermore, FGF‐4 transformed cells display low levels of FGFR‐2 mRNA and these levels are significantly increased by treatment with anti FGF‐4 neutralizing antibodies. In undifferentiated F9 EC cells, the levels of FGFR‐2 mRNA are very low and increase substantially upon induction of differentiation. The level of mRNA for FGFR‐1 are again unaffected. To gain information on the regulation of expression of the gene encoding FGFR‐2 (bek) we have cloned the FGFR‐2 promoter region and used it to drive the expression of plasmids encoding the bacterial CAT enzyme. Transfection of these plasmids into FGF treated and untreated cells did not produce significant variation in CAT activity, suggesting that FGFR‐2 downregulation in response to ligand binding occurs mainly by a post‐transcriptional mechanism. In contrast, plasmids containing as little as 140 nt of the FGFR‐2 promoter region were regulated in F9 cells, showing substantially higher expression in differentiated than in undifferentiated cells. It appears therefore that FGFR‐2 expression in fibroblasts and EC cells is regulated by somewhat different mechanisms. In contrast, FGFR‐1 expression does not vary substantially under the conditions shown to affect FGFR‐2 expression. The implications of these findings are discussed. © 1995 Wiley‐Liss, Inc.