Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.
Sci. Signal., 3 November 2009
Vol. 2, Issue 95, p. ra71
The interactions between the proteins of an infected cell and those of the infecting agent are critical determinants of the fates of both the host cell and the invading pathogen. The activation state of host guanosine triphosphatases (GTPases) are modulated by proteins from various infecting organisms, thus affecting the responses of the cell. However, examples of the reverse scenario, in which the functions of proteins from the pathogen are regulated by host GTPases, are not known. Christen et al. showed that the Salmonella virulence factor SseJ, a lipolytic enzyme that esterifies cholesterol, bound to and was activated by the GTP-bound, active form of RhoA. The activity of SseJ alters the membranes of the intracellular, vacuole-like structures in which Salmonella replicates, which is important for bacterial pathogenesis. These findings suggest that SseJ senses the activation state of RhoA in the host cell and raise the possibility that similar bacterial enzymes may also exhibit this property.
Citation: M. Christen, L. H. Coye, J. S. Hontz, D. L. LaRock, R. A. Pfuetzner, Megha, S. I. Miller, Activation of a Bacterial Virulence Protein by the GTPase RhoA. Sci. Signal.2, ra71 (2009).