A glutamate-alanine-leucine (EAL) domain protein of Salmonella controls bacterial survival in mice, antioxidant defence and killing of macrophages: role of cyclic diGMP.

Department of Microbiology and Immunology, Weill Medical College of Cornell University, and Program in Immunology and Microbial Pathogenesis, Weill Graduate School of Medical Sciences of Cornell University, New York, NY, USA.
Molecular Microbiology (Impact Factor: 5.03). 07/2005; 56(5):1234-45. DOI: 10.1111/j.1365-2958.2005.04632.x
Source: PubMed

ABSTRACT Signature-tagged transposon mutagenesis of Salmonella with differential recovery from wild-type and immunodeficient mice revealed that the gene here named cdgR[for c-diguanylate (c-diGMP) regulator] is required for the bacterium to resist host phagocyte oxidase in vivo. CdgR consists solely of a glutamate-alanine-leucine (EAL) domain, a predicted cyclic diGMP (c-diGMP) phosphodiesterase. Disruption of cdgR decreased bacterial resistance to hydrogen peroxide and accelerated bacterial killing of macrophages. An ultrasensitive assay revealed c-diGMP in wild-type Salmonella with increased levels in the CdgR-deficient mutant. Thus, besides its known role in regulating cellulose synthesis and biofilm formation, bacterial c-diGMP also regulates host-pathogen interactions involving antioxidant defence and cytotoxicity.

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Available from: Michael U Shiloh, Jul 08, 2015
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    • "For instance, cellulose synthesis is affected by cyclic di-GMP levels in Gluconacetobacter xylinus (Ross et al., 1987), and biofilm formation and motility in Pseudomonas aeruginosa are regulated by cyclic di-GMP levels (Hickman et al., 2005). In both Vibrio cholerae (Tischler and Camilli, 2004) and Salmonella enterica serovar Typhimurium (Hisert et al., 2005), reduction of cyclic di-GMP concentration results in the induction of virulence genes. Cyclic di-GMP has also been shown to interact directly with riboswitch Cd1, where a decrease in cyclic di-GMP concentration increases the level of translation of the downstream flagella operon (Sudarsan et al., 2008). "
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