Understanding signal transduction during bacterial infection.

Many known or suspected bacterial virulence factors require environmentally responsive control factors for expression. In Bordetella species, the BvgAS system represses and activates sets of genes, and mediates a biphasic phenotypic transition. Studies using mutants with altered signaling pathways and reversed regulatory connections have provided insights into the role of BvgAS and this phenotypic transition during the Bordetella-host interaction.