Demethylation of methyl-accepting chemotaxis proteins in Escherichia coli induced by the repellents glycerol and ethylene glycol.

AUTOR(ES)

Oosawa, K

RESUMO

The addition of glycerol or ethylene glycol caused not only severe tumbling but also a drastic decrease in the methylation level of methyl-accepting chemotaxis proteins (MCPs) in Escherichia coli. Experiments with various mutants having defects in their MCPs showed that the demethylation occurred in all three kinds of MCPs, MCPI, II, and III. The addition of an attractant to the glycerol- or ethylene glycol-treated cells resulted in a distinct increase in the methylation level of the relevant MCP, indicating that glycerol and ethylene glycol do not directly damage the methylation-demethylation system in the cell. The time courses of adaptation and MCP demethylation upon addition of these repellents were consistent with each other. Furthermore, both the response time and the extent of MCP demethylation were increased in parallel with increasing concentrations of glycerol or ethylene glycol. These results indicate that the adaptation to these repellents is performed by the demethylation of MCPs. Thus, glycerol and ethylene glycol are novel repellents, which utilize not just one but all three kinds of MCPs for both information processing and adaptation.

Documentos Relacionados

• Attractants and repellents influence methylation and demethylation of methyl-accepting chemotaxis proteins in an extract of Escherichia coli.
• Posttranslational processing of methyl-accepting chemotaxis proteins in Escherichia coli
• Genetics of methyl-accepting chemotaxis proteins in Escherichia coli: organization of the tar region.
• Multiple electrophoretic forms of methyl-accepting chemotaxis proteins generated by stimulus-elicited methylation in Escherichia coli.
• Enzymatic deamidation of methyl-accepting chemotaxis proteins in Escherichia coli catalyzed by the cheB gene product.