The cold shock response of Lactobacillus casei: relation between HPr phosphorylation and resistance to freeze/thaw cycles.
When carrying out a proteome analysis with a ptsH3 mutant of Lactobacillus casei, we found that the cold shock protein CspA was significantly overproduced compared to the wild-type strain. We also noticed that CspA and CspB of L. casei and CSPs from other organisms exhibit significant sequence similarity to the C-terminal part of EIIA(Glc), a glucose-specific component of the phosphoenolpyruvate:sugar phosphotransferase system. This similarity suggested a direct interaction of HPr with CSPs, as histidyl-phosphorylated HPr has been shown to phosphorylate EIIA(Glc) in its C-terminal part. We therefore compared the cold shock response of several carbon catabolite repression mutants to that of the wild-type strain. Following a shift from 37 degrees C to lower temperatures (20, 15 or 10 degrees C), all mutants showed significantly reduced growth rates. Moreover, glucose-grown mutants unable to form P-Ser-HPr (ptsH1, hprK) exhibited drastically increased sensitivity to freeze/thaw cycles. However, when the same mutants were grown on ribose or maltose, they were similarly resistant to freezing and thawing as the wild-type strain. Although subsequent biochemical and genetic studies did not allow to identify the form of HPr implicated in the resistance to cold and freezing conditions, they strongly suggested a direct interaction of HPr or one of its phospho-derivatives with CspA and/or another, hitherto undetected cold shock protein in L. casei.
Beaufils
Sophie
S
Laboratoire de Microbiologie de l'Environnement (EA956 USC INRA 2017), IBFA, Université de Caen, Caen, France.
Sauvageot
Nicolas
N
Mazé
Alain
A
Laplace
Jean-Marie
JM
Auffray
Yanick
Y
Deutscher
Josef
J
Hartke
Axel
A
D000222:Adaptation, Physiological / Q000235:genetics; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D003080:Cold Temperature; D015180:Electrophoresis, Gel, Two-Dimensional; D005615:Freezing; D015964:Gene Expression Regulation, Bacterial; D006360:Heat-Shock Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D007780:Lacticaseibacillus casei / Q000235:genetics* / Q000378:metabolism; D050296:Microbial Viability / Q000235:genetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation; D017433:Protein Structure, Secondary; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment
D001426:Bacterial Proteins; D006360:Heat-Shock Proteins; D012333:RNA, Messenger; C077188:cold-shock protein CspB, Bacteria; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System