title: Characterization of mutants of the vitamin D-binding protein/group-specific component: molecular evolution of GC*1A2 and GC*1A3, common in some Asian populations.
abstract: A well defined polymorphism of vitamin D-binding/group-specific component (GC) residues in exon 11. To characterize the molecular basis of GC*1A2 and GC*1A3, common in some Asian populations, we analyzed all coding exons amplified by the polymerase chain reaction. GC*1F was divided into GC*1FC and GC*1FT by a C-T transition in the third nucleotide of the codon (TGC/T) for cysteine283 in exon 8. The sequencing of exons 8 and 11 showed that GC*1A2 and GC*1A3 had occurred on a GC*1FC genetic background. They also shared a substitution of cysteine (TGC) for arginine (CGC) at position 429 in exon 11. GC*1A2 was characterized by having glycine (GGC) instead of serine (AGC) at position 335 in exon 9. GC*1A2 evolved from GC*1FT by three mutational events, i.e. GC*1FT-->GC*1FC-->GC*1A3-->GC*1A2. No evidence was obtained for the existence of the duplicated gene GC*1F.1A2 suggested by isoelectric focusing (IEF) of serum samples. The idea that the characteristic banding pattern of GC*1F.1A2 after IEF results from partial formation of a disulfide bond in the additional cysteine at position 429 is discussed.
authors.affiliation: Institut für Anthropologie und Humangenetik, Universität München, Germany.
authors.forename: I
authors.initials: I
authors.lastname: Yuasa
authors.forename: A
authors.initials: A
authors.lastname: Kofler
authors.forename: A
authors.initials: A
authors.lastname: Braun
authors.forename: K
authors.initials: K
authors.lastname: Umetsu
authors.forename: R
authors.initials: R
authors.lastname: Bichlmaier
authors.forename: S
authors.initials: S
authors.lastname: Kammerer
authors.forename: H
authors.initials: H
authors.lastname: Cleve
mesh_terms: D000483:Alleles; D001483:Base Sequence; D005075:Biological Evolution; D004247:DNA / Q000032:analysis / Q000737:chemistry; D017931:DNA Primers / Q000737:chemistry; D005091:Exons; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D008967:Molecular Biology; D008969:Molecular Sequence Data; D009154:Mutation; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D018807:Polymorphism, Single-Stranded Conformational; D014809:Vitamin D-Binding Protein / Q000235:genetics*
chemical_list: D017931:DNA Primers; D014809:Vitamin D-Binding Protein; D004247:DNA