Hörsaal 3M07, Geo- und Umweltforschungszentrum (GUZ)
Phospholipases are a diverse class of enzymes produced both by eukaryotic hosts as well as by pathogenic microorganisms. Major insights into activation, localization, and action modes of bacterial phospholipases during infection have been elucidated in recent years. In some cases, these enzymes are potent membrane destructors, and in others they rather manipulate host signalling paths. In Legionella pneumophila, an important pneumonia-causing bacterium, phospholipases play a dominant role. At least 15 phospholipases A (PLA), three phospholipases C, and one phospholipase D are encoded in the genome. L. pneumophila PLAs divide into three major groups: the GDSL, the patatin-like, and the PlaB-like enzymes. In order to exert activity at the right time and site in infection, the variety of enzymes needs to be produced, transported, and activated in a suitable manner. Especially the latter is important because bacterial phospholipases may also harm the pathogen itself. Sophisticated activation mechanisms are therefore required to prevent self-damage before protein export but warrant activity at the pathogen–host interface. Once understood, these mechanisms may also open ways for pathogen control. In my talk I will outline a selection of the creative and purpose-driven mechanisms of Legionella to accomplish spatial and temporal enzyme control to drive the infection cycle.