title: Role of EAL-containing proteins in multicellular behavior of Salmonella enterica serovar Typhimurium.
abstract: GGDEF and EAL domain proteins are involved in turnover of the novel secondary messenger cyclic di(3'-->5')-guanylic acid (c-di-GMP) in many bacteria. The rdar morphotype, a multicellular behavior of Salmonella enterica serovar Typhimurium characterized by the expression of the extracellular matrix components cellulose and curli fimbriae is controlled by c-di-GMP. In this work the roles of the EAL and GGDEF-EAL domain proteins on rdar morphotype development were investigated. Knockout of four of 15 EAL and GGDEF-EAL domain proteins upregulated rdar morphotype expression and expression of CsgD, the central regulator of the rdar morphotype, and partially downregulated c-di-GMP concentrations. More-detailed analysis showed that the EAL domain protein STM4264 and the GGDEF-EAL domain protein STM1703, which highly downregulated the rdar morphotype, have overlapping yet distinct functions. Another subset of EAL and GGDEF-EAL domain proteins influenced multicellular behavior in liquid culture and flagellum-mediated motility. Consequently, this work has shown that several EAL and GGDEF-EAL domain proteins, which act as phosphodiesterases, play a determinative role in the expression level of multicellular behavior of Salmonella enterica serovar Typhimurium.
authors.affiliation: Department of Microbiology, Tumor and Cell Biology (MTC), Karolinska Institutet, Box 280, SE-171 77 Stockholm, Sweden.
authors.forename: Roger
authors.initials: R
authors.lastname: Simm
authors.forename: Astrid
authors.initials: A
authors.lastname: Lusch
authors.forename: Abdul
authors.initials: A
authors.lastname: Kader
authors.forename: Mats
authors.initials: M
authors.lastname: Andersson
authors.forename: Ute
authors.initials: U
authors.lastname: Römling
mesh_terms: D020816:Amino Acid Motifs; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D018441:Biofilms / Q000254:growth & development*; D006152:Cyclic GMP / Q000031:analogs & derivatives / Q000032:analysis; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial; D008954:Models, Biological; D009068:Movement; D012486:Salmonella typhimurium / Q000166:cytology / Q000235:genetics / Q000502:physiology*
chemical_list: D001426:Bacterial Proteins; C062025:bis(3',5')-cyclic diguanylic acid; D006152:Cyclic GMP