Editors' ChoiceMicrobiology

Forming Safe Havens Within

Science's STKE  22 Jun 2004:
Vol. 2004, Issue 238, pp. tw226-TW226
DOI: 10.1126/stke.2382004TW226

The propagation of invasive bacteria and mycobacteria is tightly linked to their ability to withstand delivery to the degradative compartment of the cell, the lysosome. Walburger et al. identify a mycobacterial protein involved in the modulation of phagosome-lysosome trafficking. Protein kinase G, a eukaryotic-like serine/threonine kinase from the pathogenic mycobacterium Mycobacterium tuberculosis, is responsible for inhibiting phagosome-lysosome fusion, promoting mycobacterial survival inside macrophages. Hernandez et al. find that Salmonella, the food-poisoning and typhoid fever bacterium, modulates vesicular trafficking by altering phosphoinositide metabolism through SopB, a phosphoinositide phosphatase. SopB is delivered into host cells by an invasion-associated specialized secretion system and mediates the formation of a characteristic very spacious phagosome within which Salmonella resides after internalization. In the absence of SopB, invading Salmonella reside within tight phagosomes and exhibit a membrane trafficking defect and impaired bacterial intracellular growth.

A. Walburger, A. Koul, G. Ferrari, L. Nguyen, C. Prescianotto-Baschong, K. Huygen, B. Klebl, C. Thompson, G. Bacher, J. Pieters, Protein kinase G from pathogenic mycobacteria promotes survival within macrophages. Science 304, 1800-1804 (2004). [Abstract] [Full Text]

L. D. Hernandez, K. Hueffer, M. R. Wenk, J. E. Galán, Salmonella modulates vesicular traffic by altering phosphoinositide metabolism. Science 304, 1805-1807 (2004). [Abstract] [Full Text]

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