title: Selectivity in glycosaminoglycan binding dictates the distribution and diffusion of fibroblast growth factors in the pericellular matrix.
abstract: The range of biological outcomes generated by many signalling proteins in development and homeostasis is increased by their interactions with glycosaminoglycans, particularly heparan sulfate (HS). This interaction controls the localization and movement of these signalling proteins, but whether such control depends on the specificity of the interactions is not known. We used five fibroblast growth factors with an N-terminal HaloTag (Halo-FGFs) for fluorescent labelling, with well-characterized and distinct HS-binding properties, and measured their binding and diffusion in pericellular matrix of fixed rat mammary 27 fibroblasts. Halo-FGF1, Halo-FGF2 and Halo-FGF6 bound to HS, whereas Halo-FGF10 also interacted with chondroitin sulfate/dermatan sulfate, and FGF20 did not bind detectably. The distribution of bound FGFs in the pericellular matrix was not homogeneous, and for FGF10 exhibited striking clusters. Fluorescence recovery after photobleaching showed that FGF2 and FGF6 diffused faster, whereas FGF1 diffused more slowly, and FGF10 was immobile. The results demonstrate that the specificity of the interactions of proteins with glycosaminoglycans controls their binding and diffusion. Moreover, cells regulate the spatial distribution of different protein-binding sites in glycosaminoglycans independently of each other, implying that the extracellular matrix has long-range structure.
authors.affiliation: Department of Biochemistry, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK.
authors.forename: Changye
authors.identifier: http://orcid.org/0000-0001-8602-9629
authors.initials: C
authors.lastname: Sun
authors.affiliation: Centre for Cell Imaging, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK.
authors.forename: Marco
authors.initials: M
authors.lastname: Marcello
authors.affiliation: Department of Biochemistry, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK.
authors.forename: Yong
authors.identifier: http://orcid.org/0000-0002-5594-4434
authors.initials: Y
authors.lastname: Li
authors.affiliation: Centre for Cell Imaging, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK.
authors.forename: David
authors.identifier: http://orcid.org/0000-0002-8773-5274
authors.initials: D
authors.lastname: Mason
authors.affiliation: Department of Biochemistry, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK.
authors.forename: Raphaël
authors.identifier: http://orcid.org/0000-0001-5728-0531
authors.initials: R
authors.lastname: Lévy
authors.affiliation: Department of Biochemistry, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK dgfernig@liverpool.ac.uk.
authors.forename: David G
authors.identifier: http://orcid.org/0000-0003-4875-4293
authors.initials: DG
authors.lastname: Fernig
mesh_terms: D000818:Animals; D001665:Binding Sites; D002460:Cell Line; D005109:Extracellular Matrix / Q000378:metabolism*; D005346:Fibroblast Growth Factors / Q000032:analysis / Q000378:metabolism*; D005347:Fibroblasts / Q000378:metabolism*; D006497:Heparan Sulfate / Q000378:metabolism*; D018613:Microscopy, Confocal; D061848:Optical Imaging; D021381:Protein Transport; D051381:Rats
chemical_list: D005346:Fibroblast Growth Factors; D006497:Heparan Sulfate
keywords: extracellular matrix; fibroblast growth factor; glycosaminoglycan; growth factor diffusion; heparan sulfate