Abstract
Pathogenic bacteria often 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 effector domains interfere with important host cell signaling processes.
Biography
Professor Christoph Dehio received his Ph.D. in 1992 from the University of Cologne in Germany. From 1993 to 1995, he conducted postdoctoral research at Institut Pasteur in Paris. From 1995 to 2000, he was research group leader at the Max Planck Institute for Biology in Tübingen, Germany. In 2000, he joined the Biozentrum of the University of Basel, Switzerland, as Tenure-Track Assistant Professor, where he now holds the position of a Full Professor of Molecular Microbiology and acts as Speaker of the Focal Area Infection Biology.
Professor Dehio is elected member of the German Academy of Sciences Leopoldina (2010), EMBO (2013) and the European Academy of Microbiology (2016). He was an International Research Scholar of the Howard Hughes Medical Institute (2005-2010) and member of the National Research Council of the Swiss National Science Foundation (2009-2016).
The research of Professor Dehio is dedicated to gaining a molecular understanding of pathogen – host interaction underlying chronic bacterial infection. Using the chronically infecting intracellular pathogens Bartonella and Brucella as models, his research focuses on the specific contribution of type IV secretion systems to bacterial pathogenesis and on the evolution of these virulence devices for trans-kingdom protein transfer from genuine bacterial conjugation systems mediating interbacterial DNA transfer.