Your browser doesn't support javascript.
loading
Basic fibroblast growth factor is internalized through both receptor-mediated and heparan sulfate-mediated mechanisms.
Roghani, M; Moscatelli, D.
Afiliación
  • Roghani M; Department of Cell Biology, New York University Medical Center, New York 10016.
J Biol Chem ; 267(31): 22156-62, 1992 Nov 05.
Article en En | MEDLINE | ID: mdl-1429568
Basic fibroblast growth factor (bFGF) was internalized at a rapid rate by Chinese hamster ovary (CHO) cells that do not express significant numbers of high affinity receptors for bFGF as well as CHO cells that have been transfected with cDNA encoding FGF receptor-1 or FGF receptor-2. Internalization of bFGF was completely blocked by the addition of 10 micrograms/ml heparin in the parental CHO cells but only partially inhibited in cells expressing transfected FGF receptors. Bovine aortic endothelial cells also exhibit heparin-sensitive and heparin-resistant internalization of bFGF. The internalization of bFGF through the heparin-resistant pathway in CHO cells was efficiently competed by addition of unlabeled bFGF, was proportional to the number of receptors expressed, and approached saturation, suggesting that the heparin-resistant internalization was due to high affinity receptors. Internalization of bFGF through the heparin-sensitive pathway was not efficiently competed by unlabeled bFGF and did not approach saturation at concentrations of bFGF up to 50 ng/ml, properties similar to the interaction of bFGF with low affinity heparan sulfate binding sites on the cell surface. Internalization of bFGF in CHO cells not expressing FGF receptors was inhibited by heparin, heparan sulfate, and dermatan sulfate, the same glycosaminoglycans that block binding to cell-surface heparin sulfates. Internalization of bFGF in the parental CHO cells was inhibited at the same concentrations of heparin that block binding to cell-surface heparan sulfates. Finally, inhibition of the sulfation of CHO cell heparan sulfates by the addition of chlorate or digestion of CHO cell heparan sulfates with heparinase inhibited bFGF internalization in the parental CHO cells. These results demonstrate that bFGF can be internalized through a direct interaction with cell-surface heparan sulfates. Thus, there are two pathways for internalization of bFGF: high affinity receptor-mediated and heparan sulfate-mediated.
Asunto(s)
Buscar en Google
Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Factor 2 de Crecimiento de Fibroblastos / Receptores de Factores de Crecimiento de Fibroblastos / Heparitina Sulfato Límite: Animals Idioma: En Revista: J Biol Chem Año: 1992 Tipo del documento: Article Pais de publicación: Estados Unidos
Buscar en Google
Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Factor 2 de Crecimiento de Fibroblastos / Receptores de Factores de Crecimiento de Fibroblastos / Heparitina Sulfato Límite: Animals Idioma: En Revista: J Biol Chem Año: 1992 Tipo del documento: Article Pais de publicación: Estados Unidos