title: The cyanobacterial homologue of the RNA chaperone Hfq is essential for motility of Synechocystis sp. PCC 6803.
abstract: The ssr3341 locus was previously suggested to encode an orthologue of the RNA chaperone Hfq in the cyanobacterium Synechocystis sp. strain PCC 6803. Insertional inactivation of this gene resulted in a mutant that was not naturally transformable and exhibited a non-phototactic phenotype compared with the wild-type. The loss of motility was complemented by reintroduction of the wild-type gene, correlated with the re-establishment of type IV pili on the cell surface. Microarray analyses revealed a small set of genes with drastically reduced transcript levels in the knockout mutant compared with the wild-type cells. Among the most strongly affected genes, slr1667, slr1668, slr2015, slr2016 and slr2018 stood out, as they belong to two operons that had previously been shown to be involved in motility, controlled by the cAMP receptor protein SYCRP1. This suggests a link between cAMP signalling, motility and possibly the involvement of RNA-based regulation. This is believed to be the first report demonstrating a functional role of an Hfq orthologue in cyanobacteria, establishing a new factor in the control of motility.
authors.affiliation: Humboldt-University Berlin, Institute of Biology, Chausseestr. 117, 10115 Berlin, Germany.
authors.forename: Dennis
authors.initials: D
authors.lastname: Dienst
authors.affiliation: Humboldt-University Berlin, Institute of Biology, Chausseestr. 117, 10115 Berlin, Germany.
authors.forename: Ulf
authors.initials: U
authors.lastname: Dühring
authors.affiliation: Max Planck Institute for Infection Biology, Charitéplatz 1, 10117 Berlin, Germany.
authors.forename: Hans-Joachim
authors.initials: HJ
authors.lastname: Mollenkopf
authors.affiliation: Max Planck Institute for Infection Biology, Charitéplatz 1, 10117 Berlin, Germany.
authors.forename: Jörg
authors.initials: J
authors.lastname: Vogel
authors.affiliation: University of Freiburg, Faculty of Biology, Schänzlestr. 1, 79104 Freiburg, Germany.
authors.forename: Jochen
authors.initials: J
authors.lastname: Golecki
authors.affiliation: University of Freiburg, Faculty of Biology, Schänzlestr. 1, 79104 Freiburg, Germany.
authors.forename: Wolfgang R
authors.initials: WR
authors.lastname: Hess
authors.affiliation: Justus-Liebig University Giessen, Institute of Microbiology and Molecular Biology, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany.|Humboldt-University Berlin, Institute of Biology, Chausseestr. 117, 10115 Berlin, Germany.
authors.forename: Annegret
authors.initials: A
authors.lastname: Wilde
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D015152:Blotting, Northern; D000242:Cyclic AMP / Q000378:metabolism; D036781:Fimbriae Proteins / Q000235:genetics / Q000378:metabolism; D010861:Fimbriae, Bacterial / Q000502:physiology; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D046529:Microscopy, Electron, Transmission; D018832:Molecular Chaperones / Q000235:genetics* / Q000378:metabolism; D016254:Mutagenesis, Insertional; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D009876:Operon; D012329:RNA, Bacterial / Q000235:genetics / Q000378:metabolism; D011953:Receptors, Cyclic AMP / Q000235:genetics / Q000378:metabolism; D046939:Synechocystis / Q000235:genetics* / Q000378:metabolism / Q000502:physiology* / Q000648:ultrastructure
chemical_list: D001426:Bacterial Proteins; D018832:Molecular Chaperones; D012329:RNA, Bacterial; D011953:Receptors, Cyclic AMP; C405882:SYCRP1 protein, Synechocystis; D036781:Fimbriae Proteins; D000242:Cyclic AMP