title: Identification of Candidate Host Cell Factors Required for Actin-Based Motility of Burkholderia pseudomallei.
abstract: Intracellular actin-based motility of the melioidosis pathogen Burkholderia pseudomallei requires the bacterial factor BimA. Located at one pole of the bacterium, BimA recruits and polymerizes cellular actin to promote bacterial motility within and between cells. Here, we describe an affinity approach coupled with mass spectrometry to identify cellular proteins recruited to BimA-expressing bacteria under conditions that promote actin polymerization. We identified a group of cellular proteins that are recruited to the B. pseudomallei surface in a BimA-dependent manner, a subset of which were independently validated with specific antisera including the ubiquitous scaffold protein Ras GTPase-activating-like protein (IQGAP1). IQGAP1 integrates several key cellular signaling pathways including those involved in actin dynamics and has been shown to be involved in the adhesion of attaching and effacing Escherichia coli to infected cells and invasion of host cells by Salmonella enterica serovar Typhimurium. Although a direct interaction between BimA and IQGAP1 could not be detected using either conventional pulldown or yeast two hybrid techniques, confocal microscopy revealed that IQGAP1 is recruited to B. pseudomallei actin tails in infected cells, and siRNA-mediated knockdown highlighted a role for this protein in controlling the length and actin density of B. pseudomallei actin tails.
authors.affiliation: The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh , Easter Bush, Midlothian, EH25 9RG, United Kingdom.|Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University Bangkok, 73170 Thailand.
authors.forename: Niramol
authors.initials: N
authors.lastname: Jitprasutwit
authors.affiliation: The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh , Easter Bush, Midlothian, EH25 9RG, United Kingdom.
authors.forename: Nurhamimah
authors.initials: N
authors.lastname: Zainal-Abidin
authors.affiliation: The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh , Easter Bush, Midlothian, EH25 9RG, United Kingdom.
authors.forename: Charles
authors.initials: C
authors.lastname: Vander Broek
authors.affiliation: The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh , Easter Bush, Midlothian, EH25 9RG, United Kingdom.
authors.forename: Dominic
authors.initials: D
authors.lastname: Kurian
authors.affiliation: Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University Bangkok, 73170 Thailand.
authors.forename: Sunee
authors.initials: S
authors.lastname: Korbsrisate
authors.affiliation: The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh , Easter Bush, Midlothian, EH25 9RG, United Kingdom.
authors.forename: Mark P
authors.initials: MP
authors.lastname: Stevens
authors.affiliation: The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh , Easter Bush, Midlothian, EH25 9RG, United Kingdom.
authors.forename: Joanne M
authors.initials: JM
authors.lastname: Stevens
mesh_terms: D000199:Actins / Q000378:metabolism*; D001426:Bacterial Proteins / Q000032:analysis / Q000502:physiology; D016957:Burkholderia pseudomallei / Q000737:chemistry* / Q000166:cytology; D002465:Cell Movement; D016764:Cell Polarity; D006801:Humans; D008840:Microfilament Proteins / Q000378:metabolism / Q000502:physiology; D058105:Polymerization; D020703:ras GTPase-Activating Proteins / Q000378:metabolism / Q000502:physiology
chemical_list: D000199:Actins; D001426:Bacterial Proteins; C503173:BimA protein, Burkholderia pseudomallei; C101203:IQ motif containing GTPase activating protein 1; D008840:Microfilament Proteins; D020703:ras GTPase-Activating Proteins
keywords: BimA; Burkholderia pseudomallei; IQGAP1; actin-based motility; intracellular bacterial pathogen; melioidosis