12.00pm Monday, 11 December
2nd floor, Microbiology Building
720 Cumberland St
Department of Microbiology and Immunology
University of Otago
Listeria monocytogenes is a food-borne bacterium that causes gastroenteritis, meningitis, or abortion. Internalisation of Listeria into human cells is mediated by binding of the bacterial surface-protein InlB to its host receptor Met. At least two host physiological processes, actin polymerisation and exocytosis, are stimulated downstream of Met to allow uptake of Listeria. Using RNA interference, I demonstrated important roles for the human kinase mTOR and its substrate Protein Kinase C-α (PKC-α) in Listeria uptake. A role for the PKC-α substrate Filamin A in bacterial entry was also found. Using confocal microscopy, I demonstrated that mTOR, PKC-α, and Filamin A were each required for efficient exocytosis during InlB-mediated entry. PKC-α and Filamin A were also needed for actin polymerization during entry. Finally, the host GTPase RalA, a known binding partner of Filamin A, controls InlB-induced exocytosis and actin polymerization. My findings identify a key host signaling pathway exploited by Listeria to induce membrane trafficking and cytoskeletal alterations that mediate bacterial infection.
This seminar is kindly sponsored by: BD Biosciences