title: Analysis of the expression, regulation and export of NleA-E in Escherichia coli O157 : H7.
abstract: Previous work has shown that locus of enterocyte effacement (LEE)-encoded effector proteins such as Tir and Map can be exported via the type III secretion system (T3SS) of Escherichia coli O157 : H7. Additionally, a family of non-LEE-encoded (Nle) effector proteins has been shown to be secreted from Citrobacter rodentium, homologues of which are located on the E. coli O157 chromosome. While NleA has been shown to be secreted from pathogenic E. coli, the secretion of other Nle effector proteins has only been detected under induced conditions, or using a mutated T3SS. This study aimed to determine: (1) which nle genes are expressed in E. coli O157 : H7 under secretion-permissive conditions; (2) if Nle proteins are secreted from wild-type E. coli O157 : H7 under secretion-permissive conditions; and (3) if nle gene expression is regulated co-ordinately with other LEE-encoded effectors. Using data generated from a combination of transcriptome arrays, reporter fusions and proteomics, it was demonstrated that only nleA is expressed co-ordinately with the LEE. Secretion and expression of NleA were regulated directly or indirectly by ler, a key activator of the LEE. MS confirmed the secretion of NleA into the culture supernatant, while NleB-F were not detected.
authors.affiliation: Zoonotic and Animal Pathogens Research Laboratory, Centre for Infectious Disease, The Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB, UK.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Roe
authors.affiliation: Zoonotic and Animal Pathogens Research Laboratory, Centre for Infectious Disease, The Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB, UK.
authors.forename: Luke
authors.initials: L
authors.lastname: Tysall
authors.affiliation: Zoonotic and Animal Pathogens Research Laboratory, Centre for Infectious Disease, The Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB, UK.
authors.forename: Tracy
authors.initials: T
authors.lastname: Dransfield
authors.affiliation: Zoonotic and Animal Pathogens Research Laboratory, Centre for Infectious Disease, The Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB, UK.
authors.forename: Dai
authors.initials: D
authors.lastname: Wang
authors.affiliation: Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Midlothian EH26 0PZ, UK.
authors.forename: Douglas
authors.initials: D
authors.lastname: Fraser-Pitt
authors.affiliation: Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Midlothian EH26 0PZ, UK.|Zoonotic and Animal Pathogens Research Laboratory, Centre for Infectious Disease, The Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB, UK.
authors.forename: Arvind
authors.initials: A
authors.lastname: Mahajan
authors.affiliation: School of Biosciences, University of Birmingham, Birmingham B15 2TT, UK.
authors.forename: Chrystala
authors.initials: C
authors.lastname: Constandinou
authors.affiliation: Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Midlothian EH26 0PZ, UK.
authors.forename: Neil
authors.initials: N
authors.lastname: Inglis
authors.affiliation: Roslin Institute, Roslin BioCentre, Midlothian EH25 9PS, UK.
authors.forename: Alison
authors.initials: A
authors.lastname: Downing
authors.affiliation: Roslin Institute, Roslin BioCentre, Midlothian EH25 9PS, UK.
authors.forename: Richard
authors.initials: R
authors.lastname: Talbot
authors.affiliation: Institute for Comparative Medicine, University of Glasgow, Glasgow G61 1QH, UK.|Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Midlothian EH26 0PZ, UK.
authors.forename: David G E
authors.initials: DGE
authors.lastname: Smith
authors.affiliation: Zoonotic and Animal Pathogens Research Laboratory, Centre for Infectious Disease, The Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB, UK.
authors.forename: David L
authors.initials: DL
authors.lastname: Gally
mesh_terms: D019677:Artificial Gene Fusion; D015153:Blotting, Western; D044082:Citrobacter rodentium / Q000235:genetics; D019453:Escherichia coli O157 / Q000235:genetics* / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D008164:Luminescent Proteins / Q000032:analysis / Q000235:genetics; D013058:Mass Spectrometry; D020411:Oligonucleotide Array Sequence Analysis; D021381:Protein Transport; D020543:Proteome / Q000032:analysis; D012329:RNA, Bacterial / Q000032:analysis / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D037521:Virulence Factors / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D000097573:Red Fluorescent Protein
chemical_list: D029968:Escherichia coli Proteins; D008164:Luminescent Proteins; D020543:Proteome; D012329:RNA, Bacterial; D012333:RNA, Messenger; D037521:Virulence Factors; D000097573:Red Fluorescent Protein; C488216:NleA protein, E coli; C506688:Z0986 protein, E coli; C506689:Z0990 protein, E coli