Transcriptional downregulation of agr expression in Staphylococcus aureus during growth in human serum can be overcome by constitutively active mutant forms of the sensor kinase AgrC
Author(s)
James, EH
Edwards, AM
Wigneshweraraj, S
Type
Journal Article
Abstract
The temporal and cell density-dependent regulation of expression of virtually all the Staphylococcus aureus virulon is under the control of the agr (accessory gene regulatory) operon. The expression of the agr operon is subject to transcriptional regulation by the AgrA/C two-component response regulator/sensor kinase pair. During bacteraemia, a frequent syndrome caused by methicillin-resistant S. aureus (MRSA), the transcriptional downregulation of agr expression has been attributed to the sequestration of the quorum-signalling molecule auto-inducing peptide (AIP) by the human serum component apolipoprotein B as part of an innate immune response to infection. However, it is not known whether transcriptional downregulation of agr expression during growth in human serum is additionally subjected to regulation by transcription regulatory proteins that either directly or indirectly affect transcription from the agr operon promoters. Here, using chromosomal fluorescence reporters of agr expression in S. aureus, we show that the transcriptional downregulation of agr expression in human serum can be overcome using constitutive active mutant forms of AgrC. Therefore, it seems that the sequestration of the AIP is likely to be the only mechanism by which the host innate immune response limits agr expression at the transcriptional level to maintain the host–pathogen balance towards a noninvasive outcome.
Date Issued
2013-12-01
Online Publication Date
2013-12-01
2016-09-14T08:11:32Z
Date Acceptance
2013-10-17
ISSN
0378-1097
Publisher
Oxford University Press
Start Page
153
End Page
162
Journal / Book Title
FEMS Microbiology Letters
Volume
349
Issue
2
Copyright Statement
© 2013 Federation of European Microbiological Societies. This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs licence (http://creativecommons.org/licenses/by-nc-nd/3.0/) which permits non-commercial reproduction and distribution of the work, in any medium, provided the original work is not altered or transformed in any way, and that the work is properly cited.
Source Database
web-of-science
Sponsor
Biotechnology and Biological Sciences Research Council (BBSRC)
Grant Number
BB/I001492/1
Subjects
Science & Technology
Life Sciences & Biomedicine
Microbiology
MICROBIOLOGY
transcription regulation
GFP transcriptional reporters
two-component systems
INFECTIONS
INHIBITION
SYSTEMS
SARA
Bacterial Proteins
Base Sequence
Gene Expression Regulation, Bacterial
Gene Order
Humans
Intracellular Space
Molecular Sequence Data
Mutation
Operon
Promoter Regions, Genetic
Protein Kinases
Serum
Staphylococcus aureus
Trans-Activators
Transcription, Genetic
06 Biological Sciences
11 Medical And Health Sciences
07 Agricultural And Veterinary Sciences
Publication Status
Published