P. Salotra et al., EXPRESSION OF DNAK AND GROEL HOMOLOGS IN LEUCONOSTOC ESENTEROIDES IN RESPONSE TO HEAT-SHOCK, COLD SHOCK OR CHEMICAL STRESS, FEMS microbiology letters, 131(1), 1995, pp. 57-62
The mechanism of adaptation of bacteria to survive at elevated tempera
ture in the human host and the expression of heat-shock proteins in re
sponse to stress was examined by labelling with [S-35]methionine. An i
ncrease in culture temperature from 26 degrees C to 37 degrees C induc
ed expression of certain bacterial proteins (70 and 60 kDa). Heat shoc
k at 40 degrees C, cold shock (10 degrees C), ethanol treatment or ars
enite treatment also led to an increased expression of heat shock prot
eins of 70 and 60 kDa. Actinomycin D completely blocked the induction,
indicating that transcription is required for the overexpression of s
tress proteins in Leuconostoc mesenteroides. N-terminal sequence analy
sis showed that these proteins were homologous to the highly conserved
chaperone proteins DnaK and GroEL of Escherichia coli, respectively.