Salt-responsive outer membrane proteins of Vibrio anguillarum serotype O1 as revealed by comparative proteome analysis.
OBJECTIVE
Vibrio anguillarum is a universal marine pathogen causing vibriosis. Vibrio anguillarum encounters different osmolarity conditions between seawater and hosts, and its outer membrane proteins (OMPs) play a crucial role in the adaptation to changes of the surroundings. In the present study, proteomic approaches were applied to investigate the salt-responsive OMPs of V. anguillarum.


RESULTS
Lower salinity (0.85% NaCl) is more suitable for growth, survival and swimming motility of the bacterium. Comparative two-dimensional electrophoresis (2-DE) analysis reveals six differentially expressed protein spots among three different salinities, which were successfully identified as OmpU, maltoporin, flagellin B, Omp26La, Omp26La and OmpW respectively.


CONCLUSIONS
OmpW and OmpU were highly expressed at 3.5% salinity, suggesting their role in the efficient efflux of NaCl. Maltoporin was downregulated in higher salinity, indicating that higher osmolarity inhibits carbohydrate transport and bacterial growth. Omp26La, the homologue of OmpV, functions as a salt-responsive protein in lower salinity.


CONCLUSIONS
To the best of our knowledge, this is the first report describing salt stress-responsive proteins of V. anguillarum using proteomic approaches. Our results provide a useful strategy for delineating the osmoregulatory mechanism of the marine pathogens.
Kao
D-Y
DY
Graduate Institute of Biotechnology, College of Bioresources, National Ilan University, Ilan, Taiwan.
Cheng
Y-C
YC
Kuo
T-Y
TY
Lin
S-B
SB
Lin
C-C
CC
Chow
L-P
LP
Chen
W-J
WJ
D001425:Bacterial Outer Membrane Proteins / Q000032:analysis / Q000096:biosynthesis* / Q000187:drug effects*; D001426:Bacterial Proteins / Q000378:metabolism; D015180:Electrophoresis, Gel, Two-Dimensional; D040901:Proteomics / Q000379:methods; D012965:Sodium Chloride / Q000494:pharmacology*; D053719:Tandem Mass Spectrometry; D014733:Vibrio / Q000254:growth & development / Q000378:metabolism* / Q000502:physiology
D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D012965:Sodium Chloride