title: Hfq and three Hfq-dependent small regulatory RNAs-MgrR, RyhB and McaS-coregulate the locus of enterocyte effacement in enteropathogenic Escherichia coli.
abstract: Enteropathogenic Escherichia coli (EPEC) is a significant cause of infantile diarrhea and death in developing countries. The pathogenicity island locus of enterocyte effacement (LEE) is essential for EPEC to cause diarrhea. Besides EPEC, the LEE is also present in other gastrointestinal pathogens, most notably enterohemorrhagic E. coli (EHEC). Whereas transcriptional control of the LEE has been meticulously examined, posttranscriptional regulation, including the role of Hfq-dependent small RNAs, remains undercharacterized. However, the past few years have witnessed a surge in the identification of riboregulators of the LEE in EHEC. Contrastingly, the posttranscriptional regulatory landscape of EPEC remains cryptic. Here we demonstrate that the RNA-chaperone Hfq represses the LEE of EPEC by targeting the 5' untranslated leader region of grlR in the grlRA mRNA. Three conserved small regulatory RNAs (sRNAs)-MgrR, RyhB and McaS-are involved in the Hfq-dependent regulation of grlRA MgrR and RyhB exert their effects by directly base-pairing to the 5' region of grlR Whereas MgrR selectively represses grlR but activates grlA, RyhB represses gene expression from the entire grlRA transcript. Meanwhile, McaS appears to target the grlRA mRNA indirectly. Thus, our results provide the first definitive evidence that implicates multiple sRNAs in regulating the LEE and the resulting virulence of EPEC.
authors.affiliation: Department of Biology, Saint Joseph's University, 5600 City Avenue, Science Center, Philadelphia, PA 19131, USA sbhatt@sju.edu.
authors.forename: Shantanu
authors.initials: S
authors.lastname: Bhatt
authors.affiliation: Department of Biology, Saint Joseph's University, 5600 City Avenue, Science Center, Philadelphia, PA 19131, USA.
authors.forename: Marisa
authors.initials: M
authors.lastname: Egan
authors.affiliation: Department of Biology, Saint Joseph's University, 5600 City Avenue, Science Center, Philadelphia, PA 19131, USA.
authors.forename: Jasmine
authors.initials: J
authors.lastname: Ramirez
authors.affiliation: Department of Biology, Saint Joseph's University, 5600 City Avenue, Science Center, Philadelphia, PA 19131, USA.
authors.forename: Christian
authors.initials: C
authors.lastname: Xander
authors.affiliation: Department of Biology, Saint Joseph's University, 5600 City Avenue, Science Center, Philadelphia, PA 19131, USA.
authors.forename: Valerie
authors.initials: V
authors.lastname: Jenkins
authors.affiliation: Department of Biology, Saint Joseph's University, 5600 City Avenue, Science Center, Philadelphia, PA 19131, USA.
authors.forename: Sarah
authors.initials: S
authors.lastname: Muche
authors.affiliation: Department of Biology, Saint Joseph's University, 5600 City Avenue, Science Center, Philadelphia, PA 19131, USA.
authors.forename: Jihad
authors.initials: J
authors.lastname: El-Fenej
authors.affiliation: Department of Biology, Saint Joseph's University, 5600 City Avenue, Science Center, Philadelphia, PA 19131, USA.
authors.forename: Jamie
authors.initials: J
authors.lastname: Palmer
authors.affiliation: Department of Biology, Saint Joseph's University, 5600 City Avenue, Science Center, Philadelphia, PA 19131, USA.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Mason
authors.affiliation: Department of Biology, Saint Joseph's University, 5600 City Avenue, Science Center, Philadelphia, PA 19131, USA.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Storm
authors.affiliation: Department of Biology, Saint Joseph's University, 5600 City Avenue, Science Center, Philadelphia, PA 19131, USA.
authors.forename: Thomas
authors.initials: T
authors.lastname: Buerkert
mesh_terms: D024506:5' Flanking Region; D001483:Base Sequence; D001665:Binding Sites; D054308:Enteropathogenic Escherichia coli / Q000235:genetics* / Q000378:metabolism; D004927:Escherichia coli Infections / Q000382:microbiology*; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D035001:Host Factor 1 Protein / Q000235:genetics* / Q000378:metabolism; D010750:Phosphoproteins / Q000235:genetics* / Q000378:metabolism; D011485:Protein Binding; D012333:RNA, Messenger / Q000235:genetics; D058727:RNA, Small Untranslated / Q000235:genetics*
chemical_list: D029968:Escherichia coli Proteins; C087373:Hfq protein, E coli; D035001:Host Factor 1 Protein; C457340:LEE protein, E coli; D010750:Phosphoproteins; D012333:RNA, Messenger; D058727:RNA, Small Untranslated
keywords: EPEC; Hfq; LEE; McaS; MgrR; RyhB