RNA target profiles direct the discovery of virulence functions for the cold-shock proteins CspC and CspE

Charlotte Michaux, Erik Holmqvist, Erin Vasicek, Malvika Sharan, Lars Barquist, Alexander J Westermann, John S Gunn, Jörg Vogel

Abstract: The functions of many bacterial RNA-binding proteins remain obscure because of a lack of knowledge of their cellular ligands. Although well-studied cold-shock protein A (CspA) family members are induced and function at low temperature, others are highly expressed in infection-relevant conditions. Here, we have profiled transcripts bound in vivo by the CspA family members of Salmonella enterica serovar Typhimurium to link the constitutively expressed CspC and CspE proteins with virulence pathways. Phenotypic assays in vitro demonstrated a crucial role for these proteins in membrane stress, motility, and biofilm formation. Moreover, double deletion of cspC and cspE fully attenuates Salmonella in systemic mouse infection.