title: Coordinate up-regulation of carotenoid biosynthesis as a response to light stress in Synechococcus PCC7942.
abstract: Carotenoid biosynthesis is up-regulated by strong light in the cyanobacterium Synechococcus. By blocking off the pathway at the level of phytoene conversion, light-dependent accumulation of phytoene was observed. Real-time PCR studies demonstrated that four genes of the carotenogenic pathway are under transcriptional control. These were the genes encoding phytoene synthase, phytoene desaturase, zeta-carotene desaturase and beta-carotene hydroxylase. The transcript of the first three follow a similar kinetics, whereas the transcript of beta-carotene hydroxylase increased much faster upon transfer to high light. Promoter activities were determined with transcriptional fusions to chloramphenicol acyltransferase as reporter enzyme. The activity of the promoter of the phytoene desaturase/synthase operon was higher under strong light.
authors.affiliation: Molecular Biosciences 213, J.W. Goethe Universität, PO Box 111932, D-60054 Frankfurt/M, Germany.
authors.forename: Lutz
authors.initials: L
authors.lastname: Schäfer
authors.forename: Manuela
authors.initials: M
authors.lastname: Sandmann
authors.forename: Sonja
authors.initials: S
authors.lastname: Woitsch
authors.forename: Gerhard
authors.initials: G
authors.lastname: Sandmann
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics; D002338:Carotenoids / Q000096:biosynthesis*; D015964:Gene Expression Regulation, Bacterial / Q000528:radiation effects; D005798:Genes, Bacterial / Q000235:genetics; D008027:Light; D009876:Operon / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D046940:Synechococcus / Q000528:radiation effects*; D015854:Up-Regulation / Q000235:genetics*; D024341:Xanthophylls / Q000096:biosynthesis* / Q000737:chemistry; D065146:Zeaxanthins
chemical_list: D001426:Bacterial Proteins; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D024341:Xanthophylls; D065146:Zeaxanthins; D002338:Carotenoids; C100185:(all-E) phytoene