The AngR protein and the siderophore anguibactin positively regulate the expression of iron-transport genes in Vibrio anguillarum.
Vibrio anguillarum virulence is associated with the presence of a plasmid-mediated iron-uptake system expressed under iron-limiting conditions, which consists of the siderophore anguibactin and specific iron-transport proteins. This system is maximally expressed under iron-limiting conditions and requires the AngR protein that acts as a positive regulator of anguibactin biosynthesis and also possess an EntE-like enzymatic function that may play a role in anguibactin biosynthesis. In this work, we demonstrate that in addition to possessing these functions related to anguibactin production, AngR also positively regulated transcription of the iron-transport genes fatA and fatB. We also show that transcription of angR is repressed by Fur under iron-rich conditions. In addition, we present evidence that anguibactin itself enhanced transcription of the iron-transport genes fatA and fatB, independently of AngR and the trans-acting factor (TAF) product(s). The presence of either AngR (together with the TAF product(s)) or anguibactin alone led to a partial level of expression of the iron-transport genes fatA and fatB, while full expression is achieved when AngR, the TAF products and anguibactin are all present.
Department of Molecular Microbiology and Immunology, School of Medicine, Oregon Health Sciences University, Portland 97201-3098, USA.
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Q
Chen
A M
AM
Wertheimer
M E
ME
Tolmasky
J H
JH
Crosa
D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins / Q000378:metabolism*; D001692:Biological Transport / Q000235:genetics; D004268:DNA-Binding Proteins; D015964:Gene Expression Regulation, Bacterial; D007501:Iron / Q000378:metabolism*; D026901:Membrane Transport Proteins; D010455:Peptides; D012097:Repressor Proteins / Q000378:metabolism; D017262:Siderophores / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014733:Vibrio / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity
D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C071991:FatB protein, Vibrio anguillarum; D026901:Membrane Transport Proteins; D010455:Peptides; D012097:Repressor Proteins; D017262:Siderophores; D014157:Transcription Factors; C063474:angR protein, Vibrio anguillarum; C068477:ferric uptake regulating proteins, bacterial; C071990:FatA protein, bacteria; C049469:anguibactin; D007501:Iron