Loss of fibroblast growth factor receptor 2 ligand-binding specificity in Apert syndrome.
Craniosynostosis syndromes are autosomal dominant human skeletal diseases that result from various mutations in fibroblast growth factor receptor genes (Fgfrs). Apert syndrome (AS) is one of the most severe craniosynostosis syndromes and is associated with severe syndactyly of the hands and feet and with central nervous system malformations. AS is caused by specific missense mutations in one of two adjacent amino acid residues (S252W or P253R) in the highly conserved region linking Ig-like domains II and III of FGFR2. Here we demonstrate that these mutations break one of the cardinal rules governing ligand specificity of FGFR2. We show that the S252W mutation allows the mesenchymal splice form of FGFR2 (FGFR2c) to bind and to be activated by the mesenchymally expressed ligands FGF7 or FGF10 and the epithelial splice form of FGFR2 (FGFR2b) to be activated by FGF2, FGF6, and FGF9. These data demonstrate loss of ligand specificity of FGFR2 with retained ligand dependence for receptor activation. These data suggest that the severe phenotypes of AS likely result from ectopic ligand-dependent activation of FGFR2.
Yu
K
K
Departments of Molecular Biology and Pharmacology, and Biochemistry, Washington University Medical School, Campus Box 8103, 660 South Euclid Avenue, St. Louis, MO 63110, USA.
Herr
A B
AB
Waksman
G
G
Ornitz
D M
DM
D016475:3T3 Cells; D000168:Acrocephalosyndactylia / Q000378:metabolism*; D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D019556:COS Cells; D002522:Chlorocebus aethiops; D005346:Fibroblast Growth Factors / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D008024:Ligands; D051379:Mice; D008958:Models, Molecular; D008969:Molecular Sequence Data; D020794:Receptor Protein-Tyrosine Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D051497:Receptor, Fibroblast Growth Factor, Type 2; D017468:Receptors, Fibroblast Growth Factor / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
D008024:Ligands; D017468:Receptors, Fibroblast Growth Factor; D005346:Fibroblast Growth Factors; C496353:FGFR2 protein, human; C496354:Fgfr2 protein, mouse; D020794:Receptor Protein-Tyrosine Kinases; D051497:Receptor, Fibroblast Growth Factor, Type 2