Heparan sulfate proteoglycans function as receptors for fibroblast growth factor-2 activation of extracellular signal-regulated kinases 1 and 2.
Fibroblast growth factor-2 (FGF2) activates the extracellular signal-regulated kinases 1 and 2 (ERK1/2) through its specific receptors. Interaction of FGF2 with cell-surface heparan sulfate proteoglycans has also been suggested to induce intracellular signals. Thus, we investigated whether FGF2 can stimulate ERK1/2 activation through heparan sulfate proteoglycans using mechanisms that do not depend on receptor activation in vascular smooth muscle cells. The activation of FGF receptors was inhibited by treating cells with 5'-deoxy-5'methyl-thioadenosine and by expressing truncated dominant-negative FGF receptors. In both cases, FGF2 was able to stimulate the phosphorylation of ERK1/2 despite the absence of detectable FGF receptor tyrosine kinase activity. The FGF2 activation of ERK1/2 in the absence of receptor activity was completely dependent on heparan sulfate, because this activity was abolished by heparinase III digestion of the cells. In contrast, heparinase III treatment of control cells, with functional FGF receptors, showed only slight changes in FGF2-mediated ERK1/2 activation kinetics. Thus, in addition to serving as coreceptors for FGF receptor activation, heparan sulfate proteoglycans might also function directly as receptors for FGF2-induced ERK1/2 activation. Activation of ERK1/2 via cell-surface proteoglycans could have significant biological consequences, potentially directing cell response toward growth, migration, or differentiation.
Chua
Ceres C
CC
Department of Biochemistry, Boston University School of Medicine, Boston, Mass 02118, USA.
Rahimi
Nader
N
Forsten-Williams
Kimberly
K
Nugent
Matthew A
MA
D000818:Animals; D016466:CHO Cells; D002460:Cell Line; D002465:Cell Movement / Q000187:drug effects; D006224:Cricetinae; D004247:DNA / Q000096:biosynthesis / Q000187:drug effects; D003839:Deoxyadenosines / Q000494:pharmacology; D042783:Endothelial Cells / Q000187:drug effects / Q000201:enzymology / Q000502:physiology; D004789:Enzyme Activation / Q000187:drug effects; D004815:Epidermal Growth Factor / Q000378:metabolism / Q000494:pharmacology; D016220:Fibroblast Growth Factor 1 / Q000378:metabolism / Q000494:pharmacology; D051526:Fibroblast Growth Factor 10; D016222:Fibroblast Growth Factor 2 / Q000378:metabolism / Q000494:pharmacology*; D005346:Fibroblast Growth Factors / Q000378:metabolism / Q000494:pharmacology; D006133:Growth Substances / Q000378:metabolism / Q000494:pharmacology; D019812:Heparan Sulfate Proteoglycans / Q000378:metabolism / Q000502:physiology*; D066257:Heparin-binding EGF-like Growth Factor; D006497:Heparan Sulfate / Q000378:metabolism; D036341:Intercellular Signaling Peptides and Proteins; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D009154:Mutation; D011133:Polysaccharide-Lyases / Q000494:pharmacology; D011485:Protein Binding; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics / Q000502:physiology; D051496:Receptor, Fibroblast Growth Factor, Type 1; D011956:Receptors, Cell Surface / Q000378:metabolism / Q000502:physiology; D017468:Receptors, Fibroblast Growth Factor / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D013872:Thionucleosides / Q000494:pharmacology
D004247:DNA; D003839:Deoxyadenosines; D004815:Epidermal Growth Factor; D016220:Fibroblast Growth Factor 1; D051526:Fibroblast Growth Factor 10; D016222:Fibroblast Growth Factor 2; D005346:Fibroblast Growth Factors; D006133:Growth Substances; D019812:Heparan Sulfate Proteoglycans; D066257:Heparin-binding EGF-like Growth Factor; D006497:Heparan Sulfate; D036341:Intercellular Signaling Peptides and Proteins; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D011133:Polysaccharide-Lyases; D020794:Receptor Protein-Tyrosine Kinases; D051496:Receptor, Fibroblast Growth Factor, Type 1; D011956:Receptors, Cell Surface; D017468:Receptors, Fibroblast Growth Factor; D013872:Thionucleosides; C008500:5'-methylthioadenosine; C021349:heparitinsulfate lyase