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Activating and inhibitory heparin sequences for FGF-2 (basic FGF). Distinct requirements for FGF-1, FGF-2, and FGF-4
Chlorate-treated Swiss 3T3 fibroblasts, with impaired synthesis of heparan sulfate proteoglycan, were used as target cells in assessing the ability of exogenous heparin-derived saccharides to promote the mitogenic activity of basic fibroblast growth factor 2 (FGF-2). Full-size native heparin (carryi...
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Published in: | The Journal of biological chemistry 1993-11, Vol.268 (32), p.23906-23914 |
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Main Authors: | , , , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
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Summary: | Chlorate-treated Swiss 3T3 fibroblasts, with impaired synthesis of heparan sulfate proteoglycan, were used as target cells
in assessing the ability of exogenous heparin-derived saccharides to promote the mitogenic activity of basic fibroblast growth
factor 2 (FGF-2). Full-size native heparin (carrying iduronosyl 2-O-sulfate and glucosaminyl 6-O-sulfate groups), as well
as a dodecasaccharide fraction isolated after limited deaminative cleavage of heparin, were efficient promoters, whereas the
corresponding decasaccharides, or smaller oligosaccharides, were inactive. Neither selectively 2-O-desulfated nor preferentially
6-O-desulfated heparin were active. However, the latter derivative competed with native heparin for binding to FGF-2 and thus
blocked the ability of native heparin to promote the mitogenic activity of FGF-2. The 6-O-desulfated heparin also prevented
the ability of FGF-2 to suppress myogenic differentiation in MM14 mouse myoblasts. The binding region for FGF-2 has been identified
as a pentasaccharide sequence containing a single essential O-sulfate group, at C2 of iduronic acid (1). It is proposed that
the dodecasaccharide sequence required to promote receptor signaling by FGF-2 encompasses this pentasaccharide region, which
binds the growth factor, and a site interacting with the receptor that contains essential 2-O- and 6-O-sulfate groups. Similar
studies involving the related growth factors, FGF-1 and FGF-4, revealed differential effects of saccharides. The mitogenic
effect induced by FGF-1 thus was not blocked by either the 2-O- or the 6-O-desulfated heparins. However, both of these derivatives,
at high concentrations, promote mitogenic activity of FGF-4. It is concluded that specific saccharide sequences within heparan
sulfate glycosaminoglycan chains favor the signaling by distinct members of the FGF family. |
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ISSN: | 0021-9258 1083-351X |
DOI: | 10.1016/s0021-9258(20)80471-2 |