title: RNase III controls the degradation of corA mRNA in Escherichia coli.
abstract: In Escherichia coli, the corA gene encodes a transporter that mediates the influx of Co(2+), Mg(2+), and Ni(2+) into the cell. During the course of experiments aimed at identifying RNase III-dependent genes in E. coli, we observed that steady-state levels of corA mRNA as well as the degree of cobalt influx into the cell were dependent on cellular concentrations of RNase III. In addition, changes in corA expression levels by different cellular concentrations of RNase III were closely correlated with degrees of resistance of E. coli cells to Co(2+) and Ni(2+). In vitro and in vivo cleavage analyses of corA mRNA identified RNase III cleavage sites in the 5'-untranslated region of the corA mRNA. The introduction of nucleotide substitutions at the identified RNase III cleavage sites abolished RNase III cleavage activity on corA mRNA and resulted in prolonged half-lives of the mRNA, which demonstrates that RNase III cleavage constitutes a rate-determining step for corA mRNA degradation. These findings reveal an RNase III-mediated regulatory pathway that functions to modulate corA expression and, in turn, the influx of metal ions transported by CorA in E. coli.
authors.affiliation: School of Biological Sciences, Chung-Ang University, Seoul, Republic of Korea.
authors.forename: Boram
authors.initials: B
authors.lastname: Lim
authors.forename: Se-Hoon
authors.initials: SH
authors.lastname: Sim
authors.forename: Minji
authors.initials: M
authors.lastname: Sim
authors.forename: Kyungsub
authors.initials: K
authors.lastname: Kim
authors.forename: Che Ok
authors.initials: CO
authors.lastname: Jeon
authors.forename: Younghoon
authors.initials: Y
authors.lastname: Lee
authors.forename: Nam-Chul
authors.initials: NC
authors.lastname: Ha
authors.forename: Kangseok
authors.initials: K
authors.lastname: Lee
mesh_terms: D001483:Base Sequence; D001692:Biological Transport / Q000502:physiology; D027682:Cation Transport Proteins / Q000235:genetics / Q000378:metabolism*; D003035:Cobalt / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology*; D008274:Magnesium / Q000378:metabolism; D009154:Mutation; D009532:Nickel / Q000378:metabolism; D020871:RNA Stability / Q000502:physiology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D043244:Ribonuclease III / Q000235:genetics / Q000378:metabolism*
chemical_list: D027682:Cation Transport Proteins; C514433:CorA protein, E coli; D029968:Escherichia coli Proteins; D012333:RNA, Messenger; D003035:Cobalt; D009532:Nickel; D043244:Ribonuclease III; D008274:Magnesium