title: Riboregulation in plant-associated α-proteobacteria.
abstract: The symbiotic α-rhizobia Sinorhizobium meliloti, Bradyrhizobium japonicum, Rhizobium etli and the related plant pathogen Agrobacterium tumefaciens are important model organisms for studying plant-microbe interactions. These metabolically versatile soil bacteria are characterized by complex lifestyles and large genomes. Here we summarize the recent knowledge on their small non-coding RNAs (sRNAs) including conservation, function, and interaction of the sRNAs with the RNA chaperone Hfq. In each of these organisms, an inventory of hundreds of cis- and trans-encoded sRNAs with regulatory potential was uncovered by high-throughput approaches and used for the construction of 39 sRNA family models. Genome-wide analyses of hfq mutants and co-immunoprecipitation with tagged Hfq revealed a major impact of the RNA chaperone on the physiology of plant-associated α-proteobacteria including symbiosis and virulence. Highly conserved members of the SmelC411 family are the AbcR sRNAs, which predominantly regulate ABC transport systems. AbcR1 of A. tumefaciens controls the uptake of the plant-generated signaling molecule GABA and is a central regulator of nutrient uptake systems. It has similar functions in S. meliloti and the human pathogen Brucella abortus. As RNA degradation is an important process in RNA-based gene regulation, a short overview on ribonucleases in plant-associated α-proteobacteria concludes this review.
authors.affiliation: LOEWE Centre for Synthetic Microbiology and Faculty of Biology; Philipps-Universität Marburg; Marburg, Germany.
authors.forename: Anke
authors.initials: A
authors.lastname: Becker
authors.affiliation: Microbial Biology; Ruhr University Bochum; Bochum, Germany.
authors.forename: Aaron
authors.initials: A
authors.lastname: Overlöper
authors.affiliation: LOEWE Centre for Synthetic Microbiology and Faculty of Biology; Philipps-Universität Marburg; Marburg, Germany.
authors.forename: Jan-Philip
authors.initials: JP
authors.lastname: Schlüter
authors.affiliation: Center for Biotechnology (CeBiTec); Bielefeld University; Bielefeld, Germany.
authors.forename: Jan
authors.initials: J
authors.lastname: Reinkensmeier
authors.affiliation: LOEWE Centre for Synthetic Microbiology and Faculty of Biology; Philipps-Universität Marburg; Marburg, Germany.
authors.forename: Marta
authors.initials: M
authors.lastname: Robledo
authors.affiliation: Center for Biotechnology (CeBiTec); Bielefeld University; Bielefeld, Germany.
authors.forename: Robert
authors.initials: R
authors.lastname: Giegerich
authors.affiliation: Microbial Biology; Ruhr University Bochum; Bochum, Germany.
authors.forename: Franz
authors.initials: F
authors.lastname: Narberhaus
authors.affiliation: Institute of Microbiology and Molecular Biology; University of Gießen; Gießen, Germany.
authors.forename: Elena
authors.initials: E
authors.lastname: Evguenieva-Hackenberg
mesh_terms: D020561:Alphaproteobacteria / Q000235:genetics* / Q000378:metabolism; D020029:Base Pairing; D015964:Gene Expression Regulation, Bacterial; D005810:Multigene Family; D010944:Plants / Q000382:microbiology; D020871:RNA Stability; D016372:RNA, Antisense / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012329:RNA, Bacterial / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger; D058727:RNA, Small Untranslated / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000378:metabolism; D059467:Transcriptome
chemical_list: D016372:RNA, Antisense; D012329:RNA, Bacterial; D012333:RNA, Messenger; D058727:RNA, Small Untranslated; D016601:RNA-Binding Proteins
keywords: RNA-binding protein; RNA-seq; Rhizobiales; antisense RNA; non-coding RNA; ribolysis; riboregulation; sRNA; α-proteobacteria