Actin-based motility of Burkholderia pseudomallei involves the Arp 2/3 complex, but not N-WASP and Ena/VASP proteins.
The facultative intracellular bacterium Burkholderia pseudomallei induces actin rearrangement within infected host cells leading to formation of actin tails and membrane protrusions. To investigate the underlying mechanism we analysed the contribution of cytoskeletal proteins to B. pseudomallei-induced actin tail assembly. By using green fluorescent protein (GFP)-fusion constructs, the recruitment of the Arp2/3 complex, vasodilator-stimulated phosphoprotein (VASP), Neural Wiskott-Aldrich syndrome protein (N-WASP), zyxin, vinculin, paxillin and alpha-actinin to the surface of B. pseudomallei and into corresponding actin tails was studied. In addition, antibodies against the same panel of proteins were used for immunolocalization. Whereas the Arp2/3 complex and alpha-actinin were incorporated into B. pseudomallei-induced actin tails, none of the other proteins were detected in these structures. The overexpression of an Arp2/3 binding fragment of the Scar1 protein, shown previously to block actin-based motility of Listeria, had no effect on B. pseudomallei tail formation. Infections of either N-WASP- or Ena/VASP-defective cells showed that these proteins are not essential for B. pseudomallei-induced actin polymerization. In conclusion, our results suggest that B. pseudomallei induces actin polymerization through a mechanism that differs from those evolved by Listeria, Shigella, Rickettsia or vaccinia virus.
Breitbach
Katrin
K
Institute of Medical Microbiology, Hannover Medical School, 30625 Hannover, Germany.
Rottner
Klemens
K
Klocke
Sonja
S
Rohde
Manfred
M
Jenzora
Andrea
A
Wehland
Jürgen
J
Steinmetz
Ivo
I
D051377:Actin-Related Protein 2; D051378:Actin-Related Protein 3; D000199:Actins / Q000096:biosynthesis / Q000378:metabolism*; D034961:Antigens, Nuclear / Q000145:classification / Q000502:physiology; D001426:Bacterial Proteins / Q000502:physiology*; D016957:Burkholderia pseudomallei / Q000502:physiology* / Q000648:ultrastructure; D015815:Cell Adhesion Molecules / Q000502:physiology*; D002478:Cells, Cultured; D003598:Cytoskeletal Proteins / Q000502:physiology*; D003599:Cytoskeleton / Q000737:chemistry / Q000502:physiology; D006367:HeLa Cells; D006801:Humans; D008840:Microfilament Proteins / Q000096:biosynthesis / Q000378:metabolism; D009068:Movement; D009419:Nerve Tissue Proteins / Q000502:physiology*; D010750:Phosphoproteins / Q000502:physiology*; D051300:Wiskott-Aldrich Syndrome Protein Family; D051317:Wiskott-Aldrich Syndrome Protein, Neuronal; D000098662:Vasodilator-Stimulated Phosphoprotein
C495926:ACTR2 protein, human; C495928:ACTR3 protein, human; D051377:Actin-Related Protein 2; D051378:Actin-Related Protein 3; D000199:Actins; D034961:Antigens, Nuclear; D001426:Bacterial Proteins; D015815:Cell Adhesion Molecules; D003598:Cytoskeletal Proteins; D008840:Microfilament Proteins; D009419:Nerve Tissue Proteins; D010750:Phosphoproteins; C495771:WASL protein, human; D051300:Wiskott-Aldrich Syndrome Protein Family; D051317:Wiskott-Aldrich Syndrome Protein, Neuronal; D000098662:Vasodilator-Stimulated Phosphoprotein