Expression of DnaK and GroEL homologs in Leuconostoc esenteroides in response to heat shock, cold shock or chemical stress.
The mechanism of adaptation of bacteria to survive at elevated temperature in the human host and the expression of heat-shock proteins in response to stress was examined by labelling with [35S]methionine. An increase in culture temperature from 26 degrees C to 37 degrees C induced expression of certain bacterial proteins (70 and 60 kDa). Heat shock at 40 degrees C, cold shock (10 degrees C), ethanol treatment or arsenite treatment also led to an increased expression of heat shock proteins of 70 and 60 kDa. Actinomycin D completely blocked the induction, indicating that transcription is required for the overexpression of stress proteins in Leuconostoc mesenteroides. N-terminal sequence analysis showed that these proteins were homologous to the highly conserved chaperone proteins DnaK and GroEL of Escherichia coli, respectively.
Salotra
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P
Centre for Biotechnology, Jawaharlal Nehru University, New Delhi, India.
Singh
D K
DK
Seal
K P
KP
Krishna
N
N
Jaffe
H
H
Bhatnagar
R
R
D018053:Arsenites / Q000494:pharmacology; D001426:Bacterial Proteins / Q000187:drug effects / Q000502:physiology*; D018834:Chaperonin 60 / Q000187:drug effects / Q000502:physiology*; D003080:Cold Temperature; D029968:Escherichia coli Proteins; D000431:Ethanol / Q000494:pharmacology; D018840:HSP70 Heat-Shock Proteins / Q000187:drug effects / Q000502:physiology*; D006358:Hot Temperature; D007934:Leuconostoc / Q000737:chemistry / Q000502:physiology*; D008970:Molecular Weight; D017386:Sequence Homology, Amino Acid; D017670:Sodium Compounds / Q000494:pharmacology; D013439:Sulfhydryl Reagents / Q000494:pharmacology
D018053:Arsenites; D001426:Bacterial Proteins; D018834:Chaperonin 60; D029968:Escherichia coli Proteins; D018840:HSP70 Heat-Shock Proteins; D017670:Sodium Compounds; D013439:Sulfhydryl Reagents; D000431:Ethanol; C017947:sodium arsenite; C063842:dnaK protein, E coli