Listeria monocytogenes is an intracellular human pathogen. It uses actin and other actin- associated proteins to move through the host cell cytoplasm. The surface protein ActA is the sole listerial factor needed for recruitment of host cell actin. It is polarly distributed on the bacterial surface. To identify the structural features of ActA crucial for activity and its polarized distribution I plan to: - perform deletions and point mutation analysis of different domains of ActA, followed by the analysis of the mutants in infected cells or in cytoplasmic extracts. - analyse if there is a specific sequence in ActA which serves as a targeting signal for its polar distribution.
The results of this project will help us to understand actin-based bacterial motility, a phenomenon which plays a crucial role in the dissemination of Listeria monocytogenes in the liver.