title: Identification of a novel domain of fibroblast growth factor 2 controlling its angiogenic properties.
abstract: Fibroblast growth factor 2 (FGF-2) is a potent factor modulating the activity of many cell types. Its dimerization and binding to high affinity receptors are considered to be necessary steps to induce FGF receptor phosphorylation and signaling activation. A structural analysis was carried out and a region encompassing residues 48-58 of human FGF-2 was identified, as potentially involved in FGF-2 dimerization. A peptide (FREG-48-58) derived from this region strongly and specifically inhibited FGF-2 induced proliferation and migration of primary bovine aorta endothelial cells (BAEC) in vitro, and markedly reduced FGF-2-dependent angiogenesis in two distinct in vivo assays. To further investigate the role of region 48-58, a polyclonal antibody raised against FREG-(48-58) was tested and was found to block FGF-2 action in vitro. Human FGF-2 has three histidine residues, one falling within the region 48-58. Chemical modification of histidine residues blocked FGF-2 activity and FREG-(48-58) inhibitory effect in vitro, indicating that histidine residues, in particular the one within FREG-(48-58) region, play a crucial role in the observed activity. Additional experiments showed that FREG-(48-58) specifically interacted with FGF-2, impaired FGF-2-interaction with itself, with heparin and with FGF receptor 1, and inhibited FGF-2-induced receptor phosphorylation and FGF-2 internalization. These data indicate for the first time that region 48-58 of FGF-2 is a functional domain controlling FGF-2 activity.
authors.affiliation: Laboratorio Patologia Vascolare, Istituto Dermopatico dell'Immacolata, IRCCS, 00167 Roma, Italy. a.facchiano@idi.it
authors.forename: Antonio
authors.initials: A
authors.lastname: Facchiano
authors.forename: Katia
authors.initials: K
authors.lastname: Russo
authors.forename: Angelo M
authors.initials: AM
authors.lastname: Facchiano
authors.forename: Francesco
authors.initials: F
authors.lastname: De Marchis
authors.forename: Francesco
authors.initials: F
authors.lastname: Facchiano
authors.forename: Domenico
authors.initials: D
authors.lastname: Ribatti
authors.forename: Maria S
authors.initials: MS
authors.lastname: Aguzzi
authors.forename: Maurizio C
authors.initials: MC
authors.lastname: Capogrossi
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D002642:Chick Embryo; D004730:Endothelium, Vascular / Q000166:cytology; D016222:Fibroblast Growth Factor 2 / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D006639:Histidine / Q000378:metabolism; D006801:Humans; D008969:Molecular Sequence Data; D018919:Neovascularization, Physiologic / Q000502:physiology*; D011487:Protein Conformation; D017386:Sequence Homology, Amino Acid
chemical_list: D016222:Fibroblast Growth Factor 2; D006639:Histidine