SopD acts cooperatively with SopB during Salmonella enterica serovar Typhimurium invasion.
The intracellular bacterial pathogen, Salmonella enterica serovar Typhimurium (S. typhimurium), causes disease in a variety of hosts. To invade and replicate in host cells, these bacteria subvert host molecular machinery using bacterial proteins, called effectors, which they translocate into host cells using specialized protein delivery systems. One of these effectors, SopD, contributes to gastroenteritis, systemic virulence and persistence of S. typhimurium in animal models of infection. Recently, SopD has been implicated in invasion of polarized epithelial cells and here we investigate the features of SopD-mediated invasion. We show that SopD plays a role in membrane fission and macropinosome formation during S. typhimurium invasion, events previously shown to be mediated by the SopB effector. We further demonstrate that SopD acts cooperatively with SopB to promote these events during invasion. Using live cell imaging we show that a SopD-GFP fusion does not localize to HeLa cell cytosol as previously described, but instead is membrane associated. Upon S. typhimurium infection of these cells, SopD-GFP is recruited to the invasion site, and this recruitment required the phosphatase activity of SopB. Our findings demonstrate a role for SopD in manipulation of host-cell membrane during S. typhimurium invasion and reveal the nature of its cooperative action with SopB.
Bakowski
Malina A
MA
Department of Molecular and Medical Genetics, University of Toronto, Toronto, ON, Canada, M5S 1A8.
Cirulis
Judith T
JT
Brown
Nat F
NF
Finlay
B Brett
BB
Brumell
John H
JH
D001426:Bacterial Proteins / Q000032:analysis / Q000235:genetics / Q000502:physiology*; D002462:Cell Membrane / Q000737:chemistry; D004705:Endocytosis / Q000502:physiology; D004847:Epithelial Cells / Q000382:microbiology; D017353:Gene Deletion; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000032:analysis / Q000235:genetics; D006367:HeLa Cells; D006801:Humans; D011993:Recombinant Fusion Proteins / Q000032:analysis / Q000235:genetics; D012480:Salmonella Infections / Q000382:microbiology*; D012486:Salmonella typhimurium / Q000502:physiology*; D037521:Virulence Factors / Q000502:physiology
D001426:Bacterial Proteins; D011993:Recombinant Fusion Proteins; C116105:SopD protein, Salmonella; D037521:Virulence Factors; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; C489224:SopB protein, Salmonella