title: The diaphanous-related formins promote protrusion formation and cell-to-cell spread of Listeria monocytogenes.
abstract: The Gram-positive bacterium Listeria monocytogenes is a facultative intracellular pathogen whose virulence depends on its ability to spread from cell to cell within an infected host. Although the actin-related protein 2/3 (Arp2/3) complex is necessary and sufficient for Listeria actin tail assembly, previous studies suggest that other actin polymerization factors, such as formins, may participate in protrusion formation. Here, we show that Arp2/3 localized to only a minor portion of the protrusion. Moreover, treatment of L. monocytogenes-infected HeLa cells with a formin FH2-domain inhibitor significantly reduced protrusion length. In addition, the Diaphanous-related formins 1-3 (mDia1-3) localized to protrusions, and knockdown of mDia1, mDia2, and mDia3 substantially decreased cell-to-cell spread of L. monocytogenes. Rho GTPases are known to be involved in formin activation. Our studies also show that knockdown of several Rho family members significantly influenced bacterial cell-to-cell spread. Collectively, these findings identify a Rho GTPase-formin network that is critically involved in the cell-to-cell spread of L. monocytogenes.
authors.affiliation: Cell Biology Program.
authors.forename: Ramzi
authors.initials: R
authors.lastname: Fattouh
authors.affiliation: Department of Molecular Genetics.
authors.forename: Hyunwoo
authors.initials: H
authors.lastname: Kwon
authors.affiliation: Cell Biology Program Department of Molecular Genetics.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Czuczman
authors.affiliation: Department of Cellular and Molecular Medicine, University of Ottawa, Canada.
authors.forename: John W
authors.initials: JW
authors.lastname: Copeland
authors.affiliation: Department of Molecular Genetics Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto.
authors.forename: Laurence
authors.initials: L
authors.lastname: Pelletier
authors.affiliation: Department of Chemistry and Biochemistry and Molecular Biology Institute, University of California-Los Angeles.
authors.forename: Margot E
authors.initials: ME
authors.lastname: Quinlan
authors.affiliation: Cell Biology Program Division of Gastroenterology, Hepatology, and Nutrition, Department of Paediatrics SickKids IBD Centre, Hospital for Sick Children Institute of Medical Science, University of Toronto.
authors.forename: Aleixo M
authors.initials: AM
authors.lastname: Muise
authors.affiliation: Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts.
authors.forename: Darren E
authors.initials: DE
authors.lastname: Higgins
authors.affiliation: Cell Biology Program SickKids IBD Centre, Hospital for Sick Children Department of Molecular Genetics Institute of Medical Science, University of Toronto.
authors.forename: John H
authors.initials: JH
authors.lastname: Brumell
mesh_terms: D051377:Actin-Related Protein 2 / Q000235:genetics / Q000378:metabolism; D051376:Actin-Related Protein 2-3 Complex / Q000235:genetics / Q000378:metabolism*; D051378:Actin-Related Protein 3 / Q000235:genetics / Q000378:metabolism; D048868:Adaptor Proteins, Signal Transducing / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D022081:Cell Surface Extensions / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D000080865:Formins; D055785:Gene Knockdown Techniques; D017930:Genes, Reporter; D006367:HeLa Cells; D054884:Host-Pathogen Interactions; D006801:Humans; D008089:Listeria monocytogenes / Q000472:pathogenicity / Q000502:physiology*; D008954:Models, Biological; D017434:Protein Structure, Tertiary; D013871:Thiones / Q000494:pharmacology; D014498:Uracil / Q000031:analogs & derivatives / Q000494:pharmacology; D020741:rho GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: C495926:ACTR2 protein, human; C495928:ACTR3 protein, human; D051377:Actin-Related Protein 2; D051376:Actin-Related Protein 2-3 Complex; D051378:Actin-Related Protein 3; D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; C108962:DIAPH1 protein, human; C491462:DIAPH2 protein, human; D000080865:Formins; C547376:SMIFH2 compound; D013871:Thiones; D014498:Uracil; D020741:rho GTP-Binding Proteins
keywords: Arp2/3; HeLa cells; Listeria cell-to-cell spread; Listeria monocytogenes; diaphanous formins; mDia1, mDia2, mDia3; protrusion