Protein expression analysis of Halobacillus dabanensis D-8T subjected to salt shock.
To investigate the mechanism of salt tolerance of gram-positive moderately halophilic bacteria, two-dimensional gel electrophoresis (2-D PAGE) was employed to achieve high resolution maps of proteins of Halobacillus dabanensis D-8T. Approximately 700 spots of proteins were identified from these 2-D PAGE maps. The majority of these proteins had molecular weights between 17.5 and 66 kDa, and most of them were distributed between the isoelectric points (pI) 4.0 and 5.9. Some protein spots were distributed in the more acidic region of the 2-D gel (pI <4.0). This pattern indicated that a number of proteins in the strain D-8T are acidic. To understand the adaptation mechanisms of moderately halophilic bacteria in response to sudden environmental changes, differential protein profiles of this strain were investigated by 2-D PAGE and Imagemaster 2D Platinum software after the cells were subjected to salt shock of 1 to 25% salinity for 5 and 50 min. Analysis showed 59 proteins with an altered level of expression as the result of the exposure to salt shock. Eighteen proteins had increased expression, 8 proteins were induced, and the expression of 33 proteins was down-regulated. Eight of the up-regulated proteins were identified using MALDI-TOF/MS and MASCOT, and were similar to proteins involved in signal transduction, proteins participating in energy metabolism pathways and proteins involved in stress.
Feng
De Qin
DQ
Department of Microbiology and Immunology, College of Biological Sciences, China Agricultural University and Key Laboratory of Agro-Microbial Resources and Application, Ministry of Agriculture, Beijing 100094, China.
Zhang
Bo
B
Lu
Wei Dong
WD
Yang
Su Sheng
SS
D001406:Bacillaceae / Q000737:chemistry* / Q000187:drug effects / Q000378:metabolism*; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000737:chemistry*; D015180:Electrophoresis, Gel, Two-Dimensional; D007526:Isoelectric Point; D015636:Magnesium Chloride / Q000378:metabolism; D008278:Magnesium Sulfate / Q000378:metabolism; D011189:Potassium Chloride / Q000378:metabolism; D012965:Sodium Chloride / Q000378:metabolism / Q000494:pharmacology*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D015854:Up-Regulation
D001426:Bacterial Proteins; D015636:Magnesium Chloride; D012965:Sodium Chloride; D011189:Potassium Chloride; D008278:Magnesium Sulfate