title: PerC Manipulates Metabolism and Surface Antigens in EnteropathogenicEscherichia coli.
abstract: EnteropathogenicEscherichia coliis an important cause of profuse, watery diarrhea in infants living in developing regions of the world. Typical strains of EPEC (tEPEC) possess a virulence plasmid, while related clinical isolates that lack the pEAF plasmid are termed atypical EPEC (aEPEC). tEPEC and aEPEC tend to cause acute vs. more chronic type infections, respectively. The pEAF plasmid encodes an attachment factor as well as a regulatory operon,perABC. PerC, a poorly understood regulator, was previously shown to regulate expression of the type III secretion system through Ler. Here we elucidate the regulon of PerC using RNA sequencing analysis to better our understanding of the role of the pEAF in tEPEC infection. We demonstrate that PerC controls anaerobic metabolism by increasing expression of genes necessary for nitrate reduction. A tEPEC strain overexpressing PerC exhibited a growth advantage compared to a strain lacking this regulator, when grown anaerobically in the presence of nitrate, conditions mimicking the human intestine. We show that PerC strongly down-regulates type I fimbriae expression by manipulatingfimphase variation. The quantities of a number of non-coding RNA molecules were altered by PerC. In sum, this protein controls niche adaptation, and could help to explain the function of the PerC homologs (Pch), many of which are encoded within prophages in related, Gram-negative pathogens.
authors.affiliation: Biology Department, Reed College Portland, OR, USA.
authors.forename: Jay L
authors.initials: JL
authors.lastname: Mellies
authors.affiliation: Biology Department, Reed College Portland, OR, USA.
authors.forename: Amy
authors.initials: A
authors.lastname: Platenkamp
authors.affiliation: Molecular Microbiology and Immunology, Oregon Health and Science University Portland, OR, USA.
authors.forename: Jossef
authors.initials: J
authors.lastname: Osborn
authors.affiliation: Biology Department, Reed College Portland, OR, USA.
authors.forename: Lily
authors.initials: L
authors.lastname: Ben-Avi
mesh_terms: D000693:Anaerobiosis / Q000235:genetics; D000954:Antigens, Surface / Q000235:genetics* / Q000378:metabolism*; D003967:Diarrhea / Q000382:microbiology; D054308:Enteropathogenic Escherichia coli / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D004927:Escherichia coli Infections; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism* / Q000502:physiology*; D010861:Fimbriae, Bacterial / Q000378:metabolism; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D007422:Intestines / Q000382:microbiology; D009154:Mutation; D009566:Nitrates / Q000378:metabolism; D009876:Operon / Q000235:genetics; D010957:Plasmids / Q000235:genetics; D039002:Prophages / Q000235:genetics; D022661:RNA, Untranslated; D018085:Regulon; D000069296:Type III Secretion Systems / Q000378:metabolism; D014774:Virulence / Q000235:genetics
chemical_list: D000954:Antigens, Surface; D029968:Escherichia coli Proteins; D009566:Nitrates; C569462:PerC protein, E coli; D022661:RNA, Untranslated; D000069296:Type III Secretion Systems
keywords: EPEC; Pathogenic E. coli; PerC; fim switch; niche adaptation; nitrate reduction; type I fimbriae; virulence