Dynamic remodeling of host membranes by self-organizing bacterial effectors.

During infection Legionella bacteria translocate a variety of effectors into host cells that modify host cell membrane trafficking for the benefit of the intracellular pathogen. Here we found a self-organizing system consisting of a bacterial phosphoinositide kinase and its opposing phosphatase that formed spatiotemporal patterns, including traveling waves, to remodel host cellular membranes. The Legionella effector MavQ, a phosphatidylinositol (PI) 3-kinase, was targeted to the endoplasmic reticulum (ER). MavQ and the Legionella PI 3-phosphatase SidP, even in the absence of other bacterial components, drove rapid PI 3-phosphate turnover on the ER, spontaneously forming traveling waves that spread along ER subdomains inducing vesicle/tubule budding. Thus, bacteria can exploit a self-organizing membrane-targeting mechanism to hijack host cellular structures for survival.