Previous Article | Next Article ![]()
J. Bacteriol., 02 1997, 1029-1034, Vol 179, No. 4
E Mileykovskaya and W Dowhan
The CpxA-CpxR two-component signal transduction pathway of Escherichia coli
was studied in a mutant (pss-93) lacking phosphatidylethanolamine (PE).
Several properties of this mutant are comparable to phenotypes of cpxA
point mutants, indicating that this two-component pathway is activated in
PE-deficient cells. In contrast to point mutants, cpx operon null mutants
have a wild-type phenotype. By use of this information, a cpx operon null
allele was introduced into a pss-93 mutant. Certain altered properties of
PE-deficient mutants, which were consistent with activation of the Cpx
pathway, returned to the wild- type phenotype, namely, active accumulation
of proline and thiomethyl- beta-D-galactopyranoside was partially restored
to wild-type levels, increased resistance to amikacin returned to wild-type
sensitivity, and high levels of degP expression returned to repressed
wild-type levels. Elevated levels of acetyl phosphate and nlpE gene product
can result in activation of the Cpx pathway. However, inactivation of the
nlpE gene or mutations eliminating the ability to make acetyl phosphate did
not alter the high level of degP expression in pss-93 mutants. We propose
that the lack of PE results in an alteration in cell envelope structure or
physical properties, leading to direct activation of the Cpx pathway.
Copyright © 1997, American Society for Microbiology
The Cpx two-component signal transduction pathway is activated in Escherichia coli mutant strains lacking phosphatidylethanolamine
Department of Biochemistry and Molecular Biology, University of Texas Houston-Medical School, 77225, USA.
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»