Legionella pneumophila is the causative agent of a severe pneumonia called Legionnaires'disease. The ability of Legionella to replicate inside of phagocytic cells is central to host pathogenesis and requires a specialized secretion system called Dot/Icm. The focus of this project has been to determine how the Dot/Icm system enables Legionella to create an intracellular vacuole that supports replication. Towards this end, we have demonstrated that this process involves the subversion of host vesicles derived from the endoplasmic reticulum, which are used by Legionella to remodel the plasma membrane-derived organelle it occupies initially into a vacuole that resembles the endoplasmic reticulum. Proteins delivered into host cells by the Dot/Icm system promote this membrane transport pathway. Over the past funding period we have identified multiple bacterial proteins that target the host membrane transport regulator Rab1. To understand how these proteins control membrane transport and promote biogenesis of a vacuole that permits Legionella intracellular growth, we will investigate the function of these proteins during infection of host cells by Legionella. Specifically, we will determine how the biochemical activities of these proteins are regulated spatially and temporally during infection to coordinate the cycling of Rab1 on vacuoles containing Legionella, determine how Rab1 activation on the vacuole containing Legionella can promote the recruitment and fusion of endoplasmic reticulum-derived vesicles, and determine the role host proteins that regulate phosphatidylinositol 4-phosphate play in vacuole maturation.
Intracellular pathogens represent a serious threat to human health, and to devise strategies to combat infections by these microbes a more detailed understanding of how they modulate host cell function is needed. Thus, this project is focused on determining the molecular mechanisms that allow the intracellular pathogen Legionella pneumophila to regulate vesicular transport in eukaryotic cells using novel bacterial proteins that manipulate the function of host proteins to enhance replication and survival.
|Havey, James C; Roy, Craig R (2015) Toxicity and SidJ-Mediated Suppression of Toxicity Require Distinct Regions in the SidE Family of Legionella pneumophila Effectors. Infect Immun 83:3506-14|
|Horenkamp, Florian A; Kauffman, Karlina J; Kohler, Lara J et al. (2015) The Legionella Anti-autophagy Effector RavZ Targets the Autophagosome via PI3P- and Curvature-Sensing Motifs. Dev Cell 34:569-76|
|Hardiman, Camille A; Roy, Craig R (2014) AMPylation is critical for Rab1 localization to vacuoles containing Legionella pneumophila. MBio 5:e01035-13|
|Hubber, Andree; Arasaki, Kohei; Nakatsu, Fubito et al. (2014) The machinery at endoplasmic reticulum-plasma membrane contact sites contributes to spatial regulation of multiple Legionella effector proteins. PLoS Pathog 10:e1004222|
|Del Campo, Claudia M; Mishra, Ashwini K; Wang, Yu-Hsiu et al. (2014) Structural basis for PI(4)P-specific membrane recruitment of the Legionella pneumophila effector DrrA/SidM. Structure 22:397-408|
|Horenkamp, Florian A; Mukherjee, Shaeri; Alix, Eric et al. (2014) Legionella pneumophila subversion of host vesicular transport by SidC effector proteins. Traffic 15:488-99|
|Choy, Augustine; Roy, Craig R (2013) Autophagy and bacterial infection: an evolving arms race. Trends Microbiol 21:451-6|
|Sherwood, Racquel Kim; Roy, Craig R (2013) A Rab-centric perspective of bacterial pathogen-occupied vacuoles. Cell Host Microbe 14:256-68|
|Casanova, James E; Hsu, Victor W; Jackson, Catherine L et al. (2013) Meeting report - Arf and Rab family G proteins. J Cell Sci 126:5313-6|
|Mishra, Ashwini K; Del Campo, Claudia M; Collins, Robert E et al. (2013) The Legionella pneumophila GTPase activating protein LepB accelerates Rab1 deactivation by a non-canonical hydrolytic mechanism. J Biol Chem 288:24000-11|
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