Here we show that a glycine-to-cysteine substitution at position 375 (Gly375Cys) in human FGFR3 causes ligand-independent dimerization and phosphorylation of FGFR3 and that the equivalent substitution at position 369 (Gly369Cys) in mouse FGFR3 causes dwarfism with features mimicking human achondroplasia.
Meclozine also ameliorated abnormally suppressed proliferation of human chondrosarcoma (HCS-2/8) cells that were infected with lentivirus expressing constitutively active mutants of FGFR3-K650E causing thanatophoric dysplasia, FGFR3-K650M causing SADDAN, and FGFR3-G380R causing ACH.
Using sperm DNA from donors of different ages, we determined the frequency of the nucleotide substitution in the fibroblast growth factor receptor 3 (FGFR3) gene that causes achondroplasia.
Here we compared the ubiquitylation of either wild type or a K508A 'kinase-dead' mutant of fibroblast growth factor receptor 3 (FGFR3) with that of its naturally occurring overactive mutants, G380R as in achondroplasia, or K650E involved in thanatophoric dysplasia.
The vast majority of patients with achondroplasia have a G-->A substitution at position 1138 of the fibroblast growth factor receptor (FGFR3) cDNA sequence, resulting in the substitution of an arginine for a glycine residue at position 380 of the FGFR3 protein.
In the present study, we analyzed apoptosis using a chondrogenic cell line, ATDC5, expressing the FGFR3 mutants causing ACH and thanatophoric dysplasia, which is a more severe neonatal lethal form comprising type I and type II.
The relative clinical homogeneity of achondroplasia was substantiated by demonstration of its genetic homogeneity: 100% of patients examined exhibited mutations in the transmembrane domain of FGFR-3.
Thus, it appears that recurrent mutations of a single amino acid in the transmembrane domain of the FGFR3 protein account for all cases (23/23) of achondroplasia in our series.
In classical achondroplasia (Ach), a glycine residue is replaced by an arginine at codon 380 in exon 10 of the fibroblast growth factor receptor 3 gene (FGFR3).
The mutant FGFR3 genes causing ACH and thanatophoric dysplasia (TD), which is a more severe neonatal lethal form, were introduced into a chondrogenic cell line, ATDC5.
Since the Ala391Glu substitution in FGFR3 is close to the substitutions in the transmembrane domain that result in achondroplasia, we carefully reviewed the skeletal findings in six patients.
Heterozygous mutations of the gene encoding the fibroblast growth factor receptor 3 (FGFR3) have been found in persons with achondroplasia, thanatophoric dysplasia, and hypochondroplasia.
A recurrent glycine to arginine mutation at codon 380 (G380R) in the transmembrane domain of the fibroblast growth factor receptor 3 gene was found to cause achondroplasia among different populations.
The effects of recombinant human growth hormone (rhGH) treatment for three years were compared in patients with achondroplasia (ACH) and hypochondroplasia (HCH), whose diagnosis had been confirmed by DNA analysis of the fibroblast growth factor receptor 3 gene.
The data are consistent with the idea that the ACH mutation causes a structural change which affects both the stability and the activity of FGFR3 dimers in the absence of ligand.