Evolutionary and structure/function analysis of host-targeted bacterial effectors proteins of Bartonella
Speaker: Professor Dr. Christoph Dehio, Biozentrum, University of Basel
Host: Professor Kenn Gerdes, Centre for Bacterial Stress Responses and Persistence
Abstract: Pathogenic bacteria typically use dedicated protein secretion machineries to translocate bacterial effector proteins into host cells in order to manipulate cellular signaling pathways to their benefit. Pathogens of the genus Bartonella that cause chronic blood infections in a wide range of mammals have provided insights how such trans-kingdom protein transfer systems and their translocated effectors have evolved from preexisting bacterial structures, and how they target specific host cellular signaling processes. The bartonellae employ for effector translocation so called type IV secretion machineries that evolved from the bacterial conjugation machinery. Their diverse translocated effector sets evolved from a single bacterial toxin-antitoxin module by multiple rounds of gene duplication and diversification. The effectors display multi-domain architectures that are composed of only three basic domain types that are highly versatile in function. I will use a striking example of parallel evolution to illustrate emergence of convergent effectors sets in separate Bartonella lineages. Moreover, I will provide examples of how individual effectors interfere with important host cell signaling processes.