Pathogenicity of Salmonella: SopE-mediated membrane ruffling is independent of inositol phosphate signals.
Studies [Zhou, D., Chen, L.-M., Hernandez, L., Shears, S.B., and Galán, J.E. (2001) A Salmonella inositol polyphosphatase acts in conjunction with other bacterial effectors to promote host-cell actin cytoskeleton rearrangements and bacterial internalization. Mol. Microbiol. 39, 248-259] with engineered Salmonella mutants showed that deletion of SopE attenuated the pathogen's ability to deplete host-cell InsP5 and remodel the cytoskeleton. We pursued these observations: In SopE-transfected host-cells, membrane ruffling was induced, but SopE did not dephosphorylate InsP5, nor did it recruit PTEN (a cytosolic InsP5 phosphatase) for this task. However, PTEN strengthened SopE-mediated membrane ruffling. We conclude SopE promotes host-cell InsP5 hydrolysis only with the assistance of other Salmonella proteins. Our demonstration that Salmonella-mediated cytoskeletal modifications are independent of inositolphosphates will focus future studies on elucidating alternate pathogenic consequences of InsP5 metabolism, including ion channel conductance and apoptosis.
Deleu
Sandrine
S
Inositol Signaling Section, National Institute of Environmental Health Sciences, NIH, DHSS, Research Triangle Park, NC 27709, USA.
Choi
Kuicheon
K
Reece
Jeff M
JM
Shears
Stephen B
SB
D017766:Acid Anhydride Hydrolases; D000199:Actins / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000502:physiology*; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000382:microbiology*; D003599:Cytoskeleton / Q000378:metabolism; D006801:Humans; D007295:Inositol Phosphates / Q000502:physiology*; D051059:PTEN Phosphohydrolase / Q000494:pharmacology; D012475:Salmonella / Q000472:pathogenicity*; D012480:Salmonella Infections; D015398:Signal Transduction; D014162:Transfection; D014774:Virulence
D000199:Actins; D001426:Bacterial Proteins; D007295:Inositol Phosphates; C103987:SopE protein, Salmonella; C013571:inositol pentaphosphate; D051059:PTEN Phosphohydrolase; D017766:Acid Anhydride Hydrolases; C022563:endopolyphosphatase