title: Global analysis of posttranscriptional regulation by GlmY and GlmZ in enterohemorrhagic Escherichia coli O157:H7.
abstract: Enterohemorrhagic Escherichia coli (EHEC) is a significant human pathogen and is the cause of bloody diarrhea and hemolytic-uremic syndrome. The virulence repertoire of EHEC includes the genes within the locus of enterocyte effacement (LEE) that are largely organized in five operons, LEE1 to LEE5, which encode a type III secretion system, several effectors, chaperones, and regulatory proteins. In addition, EHEC also encodes several non-LEE-encoded effectors and fimbrial operons. The virulence genes of this pathogen are under a large amount of posttranscriptional regulation. The small RNAs (sRNAs) GlmY and GlmZ activate the translation of glucosamine synthase (GlmS) in E. coli K-12, and in EHEC they destabilize the 3' fragments of the LEE4 and LEE5 operons and promote translation of the non-LEE-encoded effector EspFu. We investigated the global changes of EHEC gene expression governed by GlmY and GlmZ using RNA sequencing and gene arrays. This study extends the known effects of GlmY and GlmZ regulation to show that they promote expression of the curli adhesin, repress the expression of tryptophan metabolism genes, and promote the expression of acid resistance genes and the non-LEE-encoded effector NleA. In addition, seven novel EHEC-specific sRNAs were identified using RNA sequencing, and three of them--sRNA56, sRNA103, and sRNA350--were shown to regulate urease, fimbria, and the LEE, respectively. These findings expand the knowledge of posttranscriptional regulation in EHEC.
authors.affiliation: Department of Microbiology and Department of Biochemistry, UT Southwestern Medical Center, Dallas, Texas, USA.
authors.forename: Charley C
authors.initials: CC
authors.lastname: Gruber
authors.affiliation: Department of Microbiology and Department of Biochemistry, UT Southwestern Medical Center, Dallas, Texas, USA vanessa.sperandio@utsouthwestern.edu.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Sperandio
mesh_terms: D018829:Adhesins, Bacterial / Q000096:biosynthesis; D001422:Bacterial Adhesion / Q000235:genetics; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics; D058947:Bacterial Secretion Systems; D045744:Cell Line, Tumor; D019453:Escherichia coli O157 / Q000235:genetics / Q000276:immunology / Q000472:pathogenicity*; D029968:Escherichia coli Proteins / Q000096:biosynthesis / Q000235:genetics*; D010861:Fimbriae, Bacterial / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics*; D006367:HeLa Cells; D006463:Hemolytic-Uremic Syndrome / Q000382:microbiology; D006801:Humans; D046228:Microarray Analysis; D010750:Phosphoproteins / Q000096:biosynthesis / Q000235:genetics*; D012323:RNA Processing, Post-Transcriptional / Q000235:genetics*; D058727:RNA, Small Untranslated / Q000235:genetics / Q000378:metabolism*; D014364:Tryptophan / Q000378:metabolism; D014510:Urease / Q000096:biosynthesis; D014774:Virulence / Q000235:genetics; D037521:Virulence Factors / Q000096:biosynthesis; D005945:Glutamine-Fructose-6-Phosphate Transaminase (Isomerizing)
chemical_list: D018829:Adhesins, Bacterial; D001426:Bacterial Proteins; D058947:Bacterial Secretion Systems; D029968:Escherichia coli Proteins; D010750:Phosphoproteins; D058727:RNA, Small Untranslated; D014364:Tryptophan; D014510:Urease; D037521:Virulence Factors; C457340:LEE protein, E coli; C488216:NleA protein, E coli; C077481:Crl protein, Bacteria; C000731191:component S, glutamate mutase protein, Bacteria; D005945:Glutamine-Fructose-6-Phosphate Transaminase (Isomerizing)