Dr. Laura Czech, Center for Synthetic Microbiology, Philipps-Universität Marburg
“Stress adaptation in bacteria: from osmotic stress response to membrane protein biogenesis”
Bacteria are masters of change – to survive environmental fluctuations, it requires sensing, signal transduction and adaptation. In their natural habitats, different ecosystems, and host-associated lifestyles bacteria are facing a large variety of biotic and abiotic stress factors challenging their growth and survival. Among abiotic stress factors are changes in osmotic potential, which bacteria face e.g., in the soil through desiccation rainfall cycles, during host infection or in the context of the human microbiome at the stomach-small intestine barrier. Moreover, microorganisms are exposed to changes in their environment due to fluctuations in temperature and the availability of nutrients. Here, I will first present bacterial adaptation systems to changes in external salt concentrations with a special focus on the widely used bacterial stress protectants ectoine and hydroxyectoine. From a more general perspective, I will introduce the bacterial second messengers (p)ppGpp, which function as central players of a pleiotropic metabolic adaptation mechanism named the stringent response. Finally, I will give detailed mechanistic insights how (p)ppGpp restricts the membrane insertion and secretion of proteins through interaction with the signal recognition particle (SRP).
(invited by Amanda Okolie / Filker group; pre-talk meeting with RTG doctoral students at 3 pm in 13-360)