Vibrio parahaemolyticus kills infected host cells within hours using three parallel mechanisms, including autophagy, cell rounding, and cell lysis. Yarbrough et al. now describe a molecular mechanism used by this pathogen to induce cell rounding. The effector, VopS, disrupts signaling by the Rho family of guanosine triphosphatases (GTPases) by modifying a threonine residue in the GTPases with adenosine 5′-monophosphate (AMP). This modification, AMPylation, prevents the GTPases from interacting with downstream effectors, which are required to mediate actin assembly.
M. L. Yarbrough, Y. Li, L. N. Kinch, N. V. Grishin, H. L. Ball, K. Orth, AMPylation of Rho GTPases by Vibrio VopS disrupts effector binding and downstream signaling. Science 323, 269–272 (2009). [Abstract] [Full Text]