title: Characterization of fibroblast growth factor-6 expressed by Chinese hamster ovary cells as a glycosylated mitogen for human vascular endothelial cells.
abstract: The gene for fibroblast growth factor (FGF)-6/hst-2 was originally identified by its close homology with the FGF-4/hst-1 gene. Aside from its ability to transform cultured fibroblasts, the characteristics of FGF-6 protein have only been studied using a simple preparation from E. coli. In the present study, we expressed FGF-6 cDNA in CHO cells and characterized the resultant protein. We found that CHO cells secreted several forms of the FGF-6 polypeptide, and that there were multiple N-terminal modifications. The longest form (18-kDa) contained the sequence, SerProAlaGlyAlaArg, as its N-terminus, which was consistent with the signal peptide cleavage site predicted from its primary structure. The core polypeptide was primarily modified by heterogeneous N-glycans that were sialylated to a small degree; among them, biantennary structures were found to predominate. Moreover, possible O-glycosylation was also detected. N-glycosylated FGF-6 potently induced DNA synthesis and proliferation of human vascular endothelial cells, whereas in the absence of N-glycosylation, FGF-6 mitogenicity was substantially diminished. The results clearly indicate that FGF-6 expressed by mammalian cells is a glycosylated mitogen for vascular endothelial cells and further suggests that N-glycosylation plays a key role in determining the mitogenicity of FGF-6.
authors.affiliation: Biosignaling Department, National Institute of Bioscience and Human Technology, Ibaraki, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Asada
authors.forename: A
authors.initials: A
authors.lastname: Yoneda
authors.forename: Y
authors.initials: Y
authors.lastname: Oda
authors.forename: K
authors.initials: K
authors.lastname: Ota
authors.forename: K
authors.initials: K
authors.lastname: Ozawa
authors.forename: K
authors.initials: K
authors.lastname: Fukuta
authors.forename: F
authors.initials: F
authors.lastname: Omae
authors.forename: M
authors.initials: M
authors.lastname: Asanagi
authors.forename: N
authors.initials: N
authors.lastname: Orikasa
authors.forename: M
authors.initials: M
authors.lastname: Suzuki
authors.forename: S
authors.initials: S
authors.lastname: Oka
authors.forename: T
authors.initials: T
authors.lastname: Makino
authors.forename: T
authors.initials: T
authors.lastname: Imamura
mesh_terms: D000818:Animals; D016466:CHO Cells / Q000378:metabolism*; D006224:Cricetinae; D004730:Endothelium, Vascular / Q000166:cytology* / Q000187:drug effects*; D051522:Fibroblast Growth Factor 6; D005346:Fibroblast Growth Factors; D015870:Gene Expression; D006031:Glycosylation; D006801:Humans; D008934:Mitogens / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000737:chemistry / Q000235:genetics*; D014471:Umbilical Veins / Q000166:cytology
chemical_list: C496452:FGF6 protein, human; D051522:Fibroblast Growth Factor 6; D008934:Mitogens; D011518:Proto-Oncogene Proteins; D005346:Fibroblast Growth Factors