title: Identification of novel α-gliadin genes.
abstract: Ten novel α-gliadin genes (Gli-ta, Gli-turg1, Gli-turg2, Gli-turg3, Gli-turg4, Gli-turg5, Gli-turg6, Gli-cs1, Gli-cs2, and Gli-cs3) with unique characteristics were isolated from wheat (Triticum aestivumL.), among which Gli-cs1, Gli-cs2, Gli-cs3, and Gli-turg6 were pseudogenes. Gli-cs3 and nine other sequences were much larger and smaller, respectively, than the typical α-gliadins. This variation was caused by insertion or deletion of the unique domain I and a polyglutamine region, possibly the result of illegitimate recombination. Consequently, Gli-cs3 contained 10 cysteine residues, whereas there were 2 cysteine residues only in the other nine sequences. Gli-ta/Gli-ta-like α-gliadin genes are normally expressed during the development of seeds. SDS-PAGE analysis showed that in-vitro-expressed Gli-ta could form intermolecular disulphide bonds and could be chain extenders. A protein band similar in size to Gli-ta has been observed in seed extracts, and mass spectrometry results confirm that the band contains small molecular mass α-gliadins, which is a characteristic of the novel α-gliadins. Mass spectrometry results also indicated that the two cysteine residues of Gli-ta/Gli-ta-like proteins participated in the formation of intermolecular disulphide bonds in vivo.
authors.affiliation: Triticeae Research Institute, Sichuan Agricultural University, Yaan, Sichuan, China.
authors.forename: Peng-Fei
authors.initials: PF
authors.lastname: Qi
authors.forename: Yu-Ming
authors.initials: YM
authors.lastname: Wei
authors.forename: Qing
authors.initials: Q
authors.lastname: Chen
authors.forename: Thérèse
authors.initials: T
authors.lastname: Ouellet
authors.forename: Jia
authors.initials: J
authors.lastname: Ai
authors.forename: Guo-Yue
authors.initials: GY
authors.lastname: Chen
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.forename: You-Liang
authors.initials: YL
authors.lastname: Zheng
mesh_terms: D001483:Base Sequence; D003001:Cloning, Molecular; D016000:Cluster Analysis; D017931:DNA Primers / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D005903:Gliadin / Q000235:genetics* / Q000378:metabolism*; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D020033:Protein Isoforms / Q000235:genetics*; D011544:Pseudogenes / Q000235:genetics; D017422:Sequence Analysis, DNA; D014908:Triticum / Q000235:genetics*
chemical_list: D017931:DNA Primers; D018076:DNA, Complementary; D020033:Protein Isoforms; D005903:Gliadin