Effect of heat-shock and bile salts on protein synthesis of Bifidobacterium longum revealed by [35S]methionine labelling and two-dimensional gel electrophoresis.
Experimental conditions for efficient protein radiolabelling and two-dimensional gel electrophoresis were developed for Bifidobacterium longum. Using these tools, protein synthesis in cells before and after heat-shock and bile salts treatment was investigated. Following heat-stress, 13 proteins were upregulated, of which HtrA, DnaK and GroEL were also moderately induced by bile salts, indicating close relationship between the heat and bile salts responses in bifidobacteria. Our work indicated that, as a consequence of prolonged heat-stress, HtrA undergoes sequential modification and proteolysis, and that this mechanism could be employed by bifidobacteria to respond to heat-stress.
University of Helsinki, Faculty of Veterinary Medicine, Department of Basic Veterinary Sciences, Division of Microbiology and Epidemiology, P.O. Box 66, FIN-00014 University of Helsinki, Finland. kirsi.savijoki@helsinki.fi
Kirsi
K
Savijoki
Aki
A
Suokko
Airi
A
Palva
Leena
L
Valmu
Nisse
N
Kalkkinen
Pekka
P
Varmanen
D001426:Bacterial Proteins / Q000032:analysis / Q000096:biosynthesis*; D001644:Bifidobacterium / Q000378:metabolism*; D001647:Bile Acids and Salts / Q000494:pharmacology; D018834:Chaperonin 60 / Q000032:analysis / Q000096:biosynthesis; D015180:Electrophoresis, Gel, Two-Dimensional / Q000379:methods; D006360:Heat-Shock Proteins / Q000032:analysis / Q000096:biosynthesis; D006358:Hot Temperature; D013194:Staining and Labeling; D013462:Sulfur Radioisotopes
D001426:Bacterial Proteins; D001647:Bile Acids and Salts; D018834:Chaperonin 60; D006360:Heat-Shock Proteins; D013462:Sulfur Radioisotopes