Salmonella Research Today is a free monthly online journal that collates and summarizes the latest research about Salmonella, including details on salmonella typhimurium, food poisoning, infection, treatment.

A role for the EAL-like protein STM1344 in regulation of CsgD expression and motility in Salmonella enterica serovar Typhimurium.

Simm R, Remminghorst U, Ahmad I, Zakikhany K, Römling U

Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden.

The bacterial second messenger cyclic di-GMP (c-di-GMP) regulates the transition between sessility and motility. In Salmonella enterica serovar Typhimurium, the expression of CsgD, the regulator of multicellular rdar morphotype behavior, is a major target of c-di-GMP signaling. CsgD expression is positively regulated by at least two diguanylate cyclases, GGDEF domain proteins, and negatively regulated by at least four phosphodiesterases, EAL domain proteins. Here, we show that in contrast to EAL domain proteins acting as phosphodiesterases, the EAL-like protein STM1344 regulated CsgD expression positively and motility negatively. STM1344, however, did not have a role in c-di-GMP turnover and also did not bind the nucleotide. STM1344 acted upstream of the phosphodiesterases STM1703 and STM3611, previously identified to participate in CsgD downregulation, where it repressed their expression. Consequently, although STM1344 has not retained a direct role in c-di-GMP metabolism, it still participates in the regulation of c-di-GMP turnover and has a role in the transition between sessility and motility.

Published 29 May 2009 in J Bacteriol, 191(12): 3928-37.
Full-text of this article is available online (may require subscription).

© 2004-2010 Salmonella Research Today. All Rights Reserved.