title: Novel nuclear-encoded proteins interacting with a plastid sigma factor, Sig1, in Arabidopsis thaliana.
abstract: Sigma factor binding proteins are involved in modifying the promoter preferences of the RNA polymerase in bacteria. We found the nuclear encoded protein (SibI) that is transported into chloroplasts and interacts specifically with the region 4 of Sig1 in Arabidopsis. SibI and its homologue, T3K9.5 are novel proteins, which are not homologous to any protein of known function. The expression of sibI was tissue specific, light dependent, and developmentally timed. We suggest the transcriptional regulation by sigma factor binding proteins to function in the plastids of higher plant.
authors.affiliation: Graduate School of Human and Environmental Studies, Kyoto University, Yoshida-nihonmatu-cho, Sakyo-ku, Kyoto 606-8501, Japan.
authors.forename: Kazuya
authors.initials: K
authors.lastname: Morikawa
authors.forename: Takashi
authors.initials: T
authors.lastname: Shiina
authors.forename: Shinya
authors.initials: S
authors.lastname: Murakami
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Toyoshima
mesh_terms: D017360:Arabidopsis / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D015152:Blotting, Northern; D002736:Chloroplasts / Q000378:metabolism; D018076:DNA, Complementary / Q000235:genetics / Q000302:isolation & purification; D018507:Gene Expression Regulation, Developmental / Q000528:radiation effects; D018506:Gene Expression Regulation, Plant / Q000528:radiation effects; D049452:Green Fluorescent Proteins; D008027:Light; D008164:Luminescent Proteins / Q000235:genetics; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding / Q000502:physiology; D021381:Protein Transport / Q000502:physiology; D012333:RNA, Messenger / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D012808:Sigma Factor / Q000235:genetics / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D029681:Arabidopsis Proteins; D018076:DNA, Complementary; D008164:Luminescent Proteins; D009687:Nuclear Proteins; D010940:Plant Proteins; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; C453496:SIB1 protein, Arabidopsis; D012808:Sigma Factor; C113096:sigma factor Sig1; D049452:Green Fluorescent Proteins