Co-expression of α′ and β subunits of β-conglycinin in rice seeds and its effect on the accumulation behavior of the expressed proteins

• Published in: Transgenic research 2010-10, Vol.19 (5), p.819-827
• Main Authors: Motoyama, Takayasu, Okumoto, Yutaka, Tanisaka, Takatoshi, Utsumi, Shigeru, Maruyama, Nobuyuki
• Format: Article
• Language: English
• Subjects: Animal Genetics and Genomics; Antigens, Plant - biosynthesis; Antigens, Plant - chemistry; Antigens, Plant - genetics; Biological and medical sciences; Biomedical and Life Sciences; Biomedical Engineering/Biotechnology; Biotechnology; Crosses, Genetic; Cysteine - chemistry; Electrophoresis, Polyacrylamide Gel; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Plant; Genetic crossing; Genetic Engineering; Genetic technics; Globulins - biosynthesis; Globulins - chemistry; Globulins - genetics; Glutelin; Glutens - chemistry; Glycine max - genetics; Life Sciences; Methods. Procedures. Technologies; Microscopy, Immunoelectron; Molecular Medicine; Original Paper; Oryza - genetics; Oryza - metabolism; Plant Genetics and Genomics; Plants, Genetically Modified - metabolism; Protein Interaction Mapping; Protein Multimerization; Protein Subunits; Recombinant Fusion Proteins - biosynthesis; Recombinant Fusion Proteins - chemistry; rice; Seed Storage Proteins - biosynthesis; Seed Storage Proteins - chemistry; Seed Storage Proteins - genetics; Seeds - metabolism; Soybean Proteins - biosynthesis; Soybean Proteins - chemistry; Soybean Proteins - genetics; soybeans; Transgenes; Transgenic animals and transgenic plants; Transgenics; β-Conglycinin
• ISSN: 0962-8819; 1573-9368
• DOI: 10.1007/s11248-009-9359-8

A transgenic rice that produces both the α′ and β subunits of β-conglycinin has been developed through the crossing of two types of transgenic rice. Although the accumulation level of the α′ subunit in the α′β-transgenic rice was slightly lower than that in the transgenic rice producing only the α′ subunit, the accumulation level of the β subunit in the α′β-transgenic rice was about 60% higher than that in the transgenic rice producing only the β subunit. Results from sequential extraction and gel-filtration experiments indicated that part of the β subunit formed heterotrimers with the α′ subunit in a similar manner as in soybean seeds and that the heterotrimers interacted with glutelin via cysteine residues. These results imply that the accumulation level of the β subunit in the α′β-transgenic rice increases by an indirect interaction with glutelin. Immunoelectron microscopy revealed that the α′ and β subunits are localized in a low electron-dense region of protein body-II (PB-II) and that α′ homotrimers in the α′β-transgenic rice seeds seem to accumulate outside of this low electron-dense region.