: Analysis of transcriptional regulation of an adhesin in Brucella suis and Brucella abortus

GASTÓN M. AROCENA; VERÓNICA RUIZ; DIANA M. POSADAS; ANGELES ZORREGUIETA; RODRIGO SIEIRA

Congreso; XLVI Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB); 2010

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB)

Species belonging to the Brucella genus are intracellular pathogensresponsible of an endemic disease called brucellosis. DifferentBrucella species vary in their host preference. It has been shownthat Brucella is able to adhere to epithelial cell lines. However,bacterial factors involved in adhesion and/or invasion remainunexplored. Recently, by heterologous and mutational approaches,we found that several members of the Type-V Secretion Systemautotransporter families of Brucella suis participate in bacterialadhesion to abiotic surfaces and HeLa cells. Our goal is to identifysignals and regulatory pathways that control transcription of theseadhesins in B. suis and Brucella abortus. Analyses of the adhesingenes and putative regulatory regions revealed differences in bothpromoter sequence and protein length between these species. ByEMSA assays, we identified several regulators that interactspecifically with the promoter region of one of the autotransportersBtaE. We have previously documented that these transcriptionfactors also participate in the regulation of other importantvirulence factor of Brucella. By DNAase I footprinting, weidentified their binding sites to the btaE promoter region.Differences in adhesin activity and/or expression between Brucellaspecies may contribute to a differential tissue tropism.