Journal article
Identification and Characterization of SpcU, a Chaperone Required for Efficient Secretion of the ExoU Cytotoxin
Journal of bacteriology, Vol.180(23), pp.6224-6231
12/1998
DOI: 10.1128/.180.23.6224-6231.1998
PMCID: PMC107707
PMID: 9829931
Abstract
In recent studies, we have shown that
Pseudomonas aeruginosa
strains that are acutely cytotoxic in vitro damage the lung epithelium in vivo. Genetic analysis indicated that the factor responsible for acute cytotoxicity was controlled by ExsA and therefore was part of the exoenzyme S regulon. The specific virulence determinant responsible for epithelial damage in vivo and cytotoxicity in vitro was subsequently mapped to the
exoU
locus. The present studies are focused on a genetic characterization of the
exoU
locus. Northern blot analyses and complementation experiments indicated that a region downstream of
exoU
was expressed and that the expression of this region corresponded to increased ExoU secretion. DNA sequence analysis of a region downstream of
exoU
identified several potential coding regions. One of these open reading frames, SpcU (specific
Pseudomonas
chaperone for ExoU), encoded a small 15-kDa acidic protein (137 amino acids [pI 4.4]) that possessed a leucine-rich motif associated with the Syc family of cytosolic chaperones for the
Yersinia
Yops. T7 expression analysis and nickel chromatography of histidine-tagged proteins indicated that ExoU and SpcU associated as a noncovalent complex when coexpressed in
Escherichia coli
. The association of ExoU and SpcU required amino acids 3 to 123 of ExoU. In
P. aeruginosa
, ExoU and SpcU are coordinately expressed as an operon that is controlled at the transcriptional level by ExsA.
Details
- Title: Subtitle
- Identification and Characterization of SpcU, a Chaperone Required for Efficient Secretion of the ExoU Cytotoxin
- Creators
- Viviane Finck-Barbançon - and Department of Biochemistry, Dartmouth Medical School, Hanover, New Hampshire 03755Timothy L Yahr - and Department of Biochemistry, Dartmouth Medical School, Hanover, New Hampshire 03755Dara W Frank - and Department of Biochemistry, Dartmouth Medical School, Hanover, New Hampshire 03755
- Resource Type
- Journal article
- Publication Details
- Journal of bacteriology, Vol.180(23), pp.6224-6231
- DOI
- 10.1128/.180.23.6224-6231.1998
- PMID
- 9829931
- PMCID
- PMC107707
- NLM abbreviation
- J Bacteriol
- ISSN
- 0021-9193
- eISSN
- 1098-5530
- Publisher
- American Society for Microbiology
- Language
- English
- Date published
- 12/1998
- Academic Unit
- Microbiology and Immunology
- Record Identifier
- 9984002388602771
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