fibroblast growth factor 9; FGF-9; Glia-activating factor; GAF; heparin-binding growth factor 9; HBGF-9 (FGF9)

Function

• role in regulation of embryonic development, cell proliferation, cell differentiation & cell migration
• may have a role in glial cell growth & differentiation during development, gliosis during repair & regeneration of brain tissue after damage, differentiation & survival of neuronal cells, & growth stimulation of glial tumors
• three molecular species were found (30 kD, 29 kD & 25 kDa), cleaved at Leu-4, Val-13 & Ser-34 respectively
• the smaller ones might be products of proteolytic digestion
• furthermore, there may be a functional signal sequence in the 30 kDa species which is uncleavable in the secretion step
• interacts with FGFR1, FGFR2, FGFR3 & FGFR4
• affinity between fibroblast growth factors (FGFs) & their receptors is increased by heparan sulfate glycosaminoglycans that function as coreceptors

Structure

• N-glycosylated
• monomer, homodimer
• belongs to the heparin-binding growth factors family

Compartment

secreted

Expression

Glial cells

Pathology

• defects in FGF9 are the cause of multiple synostoses syndrome type 3
• the Asn-99 mutation is associated with impaired FGF signaling, as evidenced by diminished activity of the MAPK1/MAPK2 pathway & decreases CTNNB1 & MYC expression when compared with wild-type protein
• binding of mutant protein to the receptor FGFR3 is severely impaired, although homodimerization of mutant to itself or wild-type is not detectably affected

More general terms

• fibroblast growth factor
• glycoprotein

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=2254
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:2254
• OMIM: https://mirror.omim.org/entry/600921
• OMIM: https://mirror.omim.org/entry/612961
• UniProt: http://www.uniprot.org/uniprot/P31371.html