title: A phosphofructokinase B-type carbohydrate kinase family protein, NARA5, for massive expressions of plastid-encoded photosynthetic genes in Arabidopsis.
abstract: To date, there have been no reports on screening for mutants defective in the massive accumulation of Rubisco in higher plants. Here, we describe a screening method based on the toxic accumulation of ammonia in the presence of methionine sulfoximine, a specific inhibitor of glutamine synthetase, during photorespiration initiated by the oxygenase reaction of Rubisco in Arabidopsis (Arabidopsis thaliana). Five recessive mutants with decreased amounts of Rubisco were identified and designated as nara mutants, as they contained a mutation in genes necessary for the achievement of Rubisco accumulation. The nara5-1 mutant showed markedly lower levels of plastid-encoded photosynthetic proteins, including Rubisco. Map-based cloning revealed that NARA5 encoded a chloroplast phosphofructokinase B-type carbohydrate kinase family protein of unknown function. The NARA5 protein fused to green fluorescent protein localized in chloroplasts. We conducted expression analyses of photosynthetic genes during light-induced greening of etiolated seedlings of nara5-1 and the T-DNA insertion mutant, nara5-2. Our results strongly suggest that NARA5 is indispensable for hyperexpression of photosynthetic genes encoded in the plastid genome, particularly rbcL.
authors: Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara 630-0101, Japan.
authors: Taro
authors: T
authors: Ogawa
authors: Kenji
authors: K
authors: Nishimura
authors: Takehiko
authors: T
authors: Aoki
authors: Hisabumi
authors: H
authors: Takase
authors: Ken-Ichi
authors: K
authors: Tomizawa
authors: Hiroki
authors: H
authors: Ashida
authors: Akiho
authors: A
authors: Yokota
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D018506:Gene Expression Regulation, Plant / Q000502:physiology*; D008969:Molecular Sequence Data; D005810:Multigene Family; D009154:Mutation; D010641:Phenotype; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics / Q000378:metabolism*; D010788:Photosynthesis / Q000235:genetics* / Q000502:physiology; D010802:Phylogeny; D018087:Plastids / Q000235:genetics / Q000378:metabolism*; D012273:Ribulose-Bisphosphate Carboxylase / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; C544821:NARA5 protein, Arabidopsis; D017853:Phosphotransferases (Alcohol Group Acceptor); D012273:Ribulose-Bisphosphate Carboxylase