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Sci. Signal., 25 May 2010
Vol. 3, Issue 123, p. ec156
[DOI: 10.1126/scisignal.3123ec156]


Microbiology Cytosol, Salmonella, and pH

Stella M. Hurtley

Science, AAAS, Cambridge CB2 1LQ, UK

Salmonella and other bacterial pathogens grow inside animal host cells within intracellular vacuoles. The bacteria secrete effector proteins across the vacuole membrane, altering the host-cell physiology to the pathogen’s advantage. The secretion process involves a specialized secretory apparatus, the type III secretion system, whose assembly is triggered by the low pH within the host-cell vacuole. Now, Yu et al. (see the Perspective by Collier) have identified neutral pH as a physiological signal for effector translocation by intracellular Salmonella. The process involves the disassembly of a membrane-bound regulatory complex that is also found in other animal pathogens. Thus, Salmonella exploit the low pH of the vacuole as a signal to induce assembly of the secretion system, and then the neutral pH of the cytoplasm to trigger effector translocation.

X.-J. Yu, K. McGourty, M. Liu, K. E. Unsworth, D. W. Holden, pH sensing by intracellular Salmonella induces effector translocation. Science 328, 1040–1043 (2010). [Abstract] [Full Text]

R. J. Collier, Salmonella’s safety catch. Science 328, 981–982 (2010). [Summary] [Full Text]

Citation: S. M. Hurtley, Cytosol, Salmonella, and pH. Sci. Signal. 3, ec156 (2010).

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