Genome-wide expression analyses of Campylobacter jejuni NCTC11168 reveals coordinate regulation of motility and virulence by flhA.
We examined two variants of the genome-sequenced strain, Campylobacter jejuni NCTC11168, which show marked differences in their virulence properties including colonization of poultry, invasion of Caco-2 cells, and motility. Transcript profiles obtained from whole genome DNA microarrays and proteome analyses demonstrated that these differences are reflected in late flagellar structural components and in virulence factors including those involved in flagellar glycosylation and cytolethal distending toxin production. We identified putative sigma(28) and sigma(54) promoters for many of the affected genes and found that greater differences in expression were observed for sigma(28)-controlled genes. Inactivation of the gene encoding sigma(28), fliA, resulted in an unexpected increase in transcripts with sigma(54) promoters, as well as decreased transcription of sigma(28)-regulated genes. This was unlike the transcription profile observed for the attenuated C. jejuni variant, suggesting that the reduced virulence of this organism was not entirely due to impaired function of sigma(28). However, inactivation of flhA, an important component of the flagellar export apparatus, resulted in expression patterns similar to that of the attenuated variant. These findings indicate that the flagellar regulatory system plays an important role in campylobacter pathogenesis and that flhA is a key element involved in the coordinate regulation of late flagellar genes and of virulence factors in C. jejuni.
Institute for Biological Sciences, National Research Council of Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6, Canada.
Catherine D
CD
Carrillo
Eduardo
E
Taboada
John H E
JH
Nash
Patricia
P
Lanthier
John
J
Kelly
Peter C
PC
Lau
Rachel
R
Verhulp
Oksana
O
Mykytczuk
Jonathan
J
Sy
Wendy A
WA
Findlay
Kingsley
K
Amoako
Susantha
S
Gomis
Philip
P
Willson
John W
JW
Austin
Andy
A
Potter
Lorne
L
Babiuk
Brenda
B
Allan
Christine M
CM
Szymanski
D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D018938:Caco-2 Cells; D016123:Campylobacter jejuni / Q000235:genetics*; D002465:Cell Movement; D002645:Chickens; D018076:DNA, Complementary / Q000378:metabolism; D004268:DNA-Binding Proteins; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D015180:Electrophoresis, Gel, Two-Dimensional; D005407:Flagella / Q000378:metabolism; D016680:Genome, Bacterial; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics*; D008854:Microscopy, Electron; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D011506:Proteins / Q000737:chemistry; D012313:RNA / Q000378:metabolism; D051877:RNA Polymerase Sigma 54; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D012808:Sigma Factor / Q000378:metabolism
D001426:Bacterial Proteins; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; C080688:FlhA protein, Bacteria; C064971:FliA protein, Bacteria; D008565:Membrane Proteins; D011506:Proteins; D012333:RNA, Messenger; D012808:Sigma Factor; D012313:RNA; D012321:DNA-Directed RNA Polymerases; D051877:RNA Polymerase Sigma 54