title: Inhibition of expression in Escherichia coli of a virulence regulator MglB of Francisella tularensis using external guide sequence technology.
abstract: External guide sequences (EGSs) have successfully been used to inhibit expression of target genes at the post-transcriptional level in both prokaryotes and eukaryotes. We previously reported that EGS accessible and cleavable sites in the target RNAs can rapidly be identified by screening random EGS (rEGS) libraries. Here the method of screening rEGS libraries and a partial RNase T1 digestion assay were used to identify sites accessible to EGSs in the mRNA of a global virulence regulator MglB from Francisella tularensis, a Gram-negative pathogenic bacterium. Specific EGSs were subsequently designed and their activities in terms of the cleavage of mglB mRNA by RNase P were tested in vitro and in vivo. EGS73, EGS148, and EGS155 in both stem and M1 EGS constructs induced mglB mRNA cleavage in vitro. Expression of stem EGS73 and EGS155 in Escherichia coli resulted in significant reduction of the mglB mRNA level coded for the F. tularensis mglB gene inserted in those cells.
authors.affiliation: Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA.
authors.forename: Gaoping
authors.initials: G
authors.lastname: Xiao
authors.forename: Eirik W
authors.initials: EW
authors.lastname: Lundblad
authors.forename: Mina
authors.initials: M
authors.lastname: Izadjoo
authors.forename: Sidney
authors.initials: S
authors.lastname: Altman
mesh_terms: D001483:Base Sequence; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000235:genetics*; D005604:Francisella tularensis / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D009710:Nucleotide Mapping; D012329:RNA, Bacterial / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D043262:Ribonuclease P; D037521:Virulence Factors / Q000235:genetics* / Q000378:metabolism
chemical_list: D012329:RNA, Bacterial; D012333:RNA, Messenger; D037521:Virulence Factors; D043262:Ribonuclease P