Fibroblast growth factor 4 (FGF4) is a crucial growth factor for the development of mammalian embryos. We previously produced hexahistidine-tagged, bovine and porcine FGF4 (Pro32 to Leu206) proteins without a secretory signal peptide at the aminoterminus in Escherichia coli. Here, we found that these were unstable; site-specific cleavage between Ser54 and Leu55 in both FGF4 derivatives was identified. In order to generate stable FGF4 derivatives and to investigate their biological activities, aminoterminally truncated and hexahistidine-tagged bovine and porcine FGF4 (Leu55 to Leu206) proteins, termed HisbFGF4L and HispFGF4L, respectively, were produced in E. coli. These FGF4 derivatives were sufficiently stable and exerted mitogenic activities in fibroblasts. Treatment with the FGF4 derivatives promoted the phosphorylation of ERK1/2, which are crucial kinases in the FGF signaling pathway. In the presence of PD173074, an FGF receptor inhibitor, the phosphorylation of ERK1/2 was inhibited and resulted in abolition of the growth-promoting activity of FGF4 derivatives. Taken together, we demonstrate that HisbFGF4L and HispFGF4L are capable of promoting the proliferation of bovine- and porcine-derived cells, respectively, via an authentic FGF signaling pathway. These FGF4 derivatives may be applicable for dissecting the roles of FGF4 during embryogenesis in cattle and pigs.
- Escherichia coli
ASJC Scopus subject areas
- Molecular Medicine
- Biomedical Engineering
- Applied Microbiology and Biotechnology
- Drug Discovery
- Process Chemistry and Technology