1. Multiple forms of α-glucosidase in rice seeds (Oryza sativa L., var Nipponbare)
- Author
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Masatoshi Hayashi, Atsuo Kimura, Seiya Chiba, Wongchawalit Jintanart, Kazuki Matsubara, Haruhide Mori, Tatsuya Ito, Takeshi Yamamoto, Masayuki Okuyama, Hiroyuki Nakai, Young-Min Kim, Koutarou Kamiya, and Yoshio Sano
- Subjects
Proteolysis ,Molecular Sequence Data ,Biology ,Plant Proteins, Dietary ,Polymerase Chain Reaction ,Biochemistry ,Substrate Specificity ,Post-translational proteolysis ,Sequence Homology, Nucleic Acid ,Complementary DNA ,medicine ,Starch granules degradation ,Amino Acid Sequence ,RNA, Messenger ,Gene ,chemistry.chemical_classification ,Oryza sativa ,Base Sequence ,Sequence Homology, Amino Acid ,medicine.diagnostic_test ,Alternative splicing ,food and beverages ,Oryza ,alpha-Glucosidases ,Ripening ,General Medicine ,Blotting, Northern ,Molecular biology ,Amino acid ,Isoenzymes ,Blotting, Southern ,Enzyme ,chemistry ,Multigene Family ,Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ,Seeds ,α-Glucosidase isoforms and isozymes ,Electrophoresis, Polyacrylamide Gel ,α-Glucosidase multigene family ,Protein Processing, Post-Translational - Abstract
Two isoforms of alpha-glucosidases (ONG2-I and ONG2-II) were purified from dry rice seeds (Oryza sativa L., var Nipponbare). Both ONG2-I and ONG2-II were the gene products of ONG2 mRNA expressed in ripening seeds. Each enzyme consisted of two components of 6kDa-peptide and 88kDa-peptide encoded by this order in ONG2 cDNA (ong2), and generated by post-translational proteolysis. The 88kDa-peptide of ONG2-II had 10 additional N-terminal amino acids compared with the 88kDa-peptide of ONG2-I. The peptides between 6kDa and 88kDa components (26 amino acids for ONG2-I and 16 for ONG2-II) were removed by post-translational proteolysis. Proteolysis induced changes in adsorption and degradation of insoluble starch granules. We also obtained three alpha-glucosidase cDNAs (ong1, ong3, and ong4) from ripening seeds. The ONG1, ONG2, and ONG4 genes were situated in distinct locus of rice genome. The transcripts encoding ONG2 and ONG3 were generated by alternative splicing. Members of alpha-glucosidase multigene family are differentially expressed during ripening and germinating stages in rice.
- Published
- 2007
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