title: Expression pattern of a chloroplast NADPH-dependent thioredoxin reductase in Chlorella vulgaris during hardening and its interaction with 2-Cys peroxiredoxin.
abstract: A chloroplastic NADPH-dependent thioredoxin reductase gene was identified from Chlorella vulgaris and designated CvNTRC. Mature CvNTRC protein (mCvNTRC) was expressed in Escherichia coli, and it showed both NADPH-dependent thioredoxin reductase (NTR) and thioredoxin (Trx)-like dithiol-disulfide oxidoreductase activities. The transcript of CvNTRC increased throughout 24-h hardening, whereas the encoded protein amount and total NTR activity decreased once and then increased during hardening. By in vitro pull-down assay, a 21.2-kDa protein bound to mCvNTRC was isolated and identified as a 2-Cys peroxiredoxin (2-Cys Prx) based on the N-terminal sequence. These data suggest that CvNTRC is maintained at a constant level during hardening and functions as an antioxidant with 2-Cys Prx in the acquisition of freezing tolerance of Chlorella.
authors.affiliation: Department of Bioscience and Biotechnology, Graduate School of Bioresources and Bioenvironmental Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Machida
authors.forename: Eri
authors.initials: E
authors.lastname: Kato
authors.forename: Akiko
authors.initials: A
authors.lastname: Ishibashi
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Sato
authors.forename: Shinji
authors.initials: S
authors.lastname: Kawasaki
authors.forename: Youichi
authors.initials: Y
authors.lastname: Niimura
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Honjoh
authors.forename: Takahisa
authors.initials: T
authors.lastname: Miyamoto
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D002708:Chlorella / Q000201:enzymology* / Q000502:physiology*; D002736:Chloroplasts / Q000201:enzymology*; D018076:DNA, Complementary / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D005615:Freezing; D005786:Gene Expression Regulation; D006639:Histidine / Q000378:metabolism; D008969:Molecular Sequence Data; D009249:NADP / Q000378:metabolism*; D054464:Peroxiredoxins / Q000378:metabolism*; D014176:Protein Biosynthesis; D013880:Thioredoxin-Disulfide Reductase / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013879:Thioredoxins / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D018076:DNA, Complementary; D006639:Histidine; D013879:Thioredoxins; D009249:NADP; D054464:Peroxiredoxins; D013880:Thioredoxin-Disulfide Reductase