title: DAC is involved in the accumulation of the cytochrome b6/f complex in Arabidopsis.
abstract: The biogenesis and assembly of photosynthetic multisubunit protein complexes is assisted by a series of nucleus-encoded auxiliary protein factors. In this study, we characterize the dac mutant of Arabidopsis (Arabidopsis thaliana), which shows a severe defect in the accumulation of the cytochrome b(6)/f complex, and provide evidence suggesting that the efficiency of cytochrome b(6)/f complex assembly is affected in the mutant. DAC is a thylakoid membrane protein with two predicted transmembrane domains that is conserved from cyanobacteria to vascular plants. Yeast (Saccharomyces cerevisiae) two-hybrid and coimmunoprecipitation analyses revealed a specific interaction between DAC and PetD, a subunit of the cytochrome b(6)/f complex. However, DAC was found not to be an intrinsic component of the cytochrome b(6)/f complex. In vivo chloroplast protein labeling experiments showed that the labeling rates of the PetD and cytochrome f proteins were greatly reduced, whereas that of the cytochrome b(6) protein remained normal in the dac mutant. DAC appears to be a novel factor involved in the assembly/stabilization of the cytochrome b(6)/f complex, possibly through interaction with the PetD protein.
authors.affiliation: Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
authors.forename: Jianwei
authors.initials: J
authors.lastname: Xiao
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.forename: Min
authors.initials: M
authors.lastname: Ouyang
authors.forename: Tao
authors.initials: T
authors.lastname: Yun
authors.forename: Baoye
authors.initials: B
authors.lastname: He
authors.forename: Daili
authors.initials: D
authors.lastname: Ji
authors.forename: Jinfang
authors.initials: J
authors.lastname: Ma
authors.forename: Wei
authors.initials: W
authors.lastname: Chi
authors.forename: Congming
authors.initials: C
authors.lastname: Lu
authors.forename: Lixin
authors.initials: L
authors.lastname: Zhang
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D045346:Cytochrome b6f Complex / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D011132:Polyribosomes / Q000378:metabolism; D011485:Protein Binding; D055550:Protein Stability; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D013050:Spectrometry, Fluorescence; D013347:Subcellular Fractions / Q000378:metabolism; D013395:Sucrose / Q000378:metabolism; D060431:Thylakoid Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D020524:Thylakoids / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; C581068:DAC protein, Arabidopsis; D012333:RNA, Messenger; D060431:Thylakoid Membrane Proteins; C084072:petD protein, cytochrome b(6)f complex; D013395:Sucrose; D045346:Cytochrome b6f Complex