title: Identification of host proteins involved in rickettsial invasion of tick cells.
abstract: Tick-borne spotted fever group (SFG) Rickettsia species are obligate intracellular bacteria capable of infecting both vertebrate and invertebrate host cells, an essential process for subsequent bacterial survival in distinct hosts. The host cell signaling molecules involved in the uptake of Rickettsia into mammalian and Drosophila cells have been identified; however, invasion into tick cells is understudied. Considering the movement of SFG Rickettsia between vertebrate and invertebrate hosts, the hypothesis is that conserved mechanisms are utilized for host cell invasion. The current study employed biochemical inhibition assays to determine the tick proteins involved in Rickettsia montanensis infection of tick-derived cells from a natural host, Dermacentor variabilis. The results revealed several tick proteins important for rickettsial invasion, including actin filaments, actin-related protein 2/3 complex, phosphatidylinositol-3'-kinase, protein tyrosine kinases (PTKs), Src family PTK, focal adhesion kinase, Rho GTPase Rac1, and neural Wiskott-Aldrich syndrome protein. Delineating the molecular mechanisms of rickettsial infection is critical to a thorough understanding of rickettsial transmission in tick populations and the ecology of tick-borne rickettsial diseases.
authors.affiliation: Vector-borne Disease Laboratories, Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana, USA npetchampai@vetmed.lsu.edu.
authors.forename: Natthida
authors.initials: N
authors.lastname: Petchampai
authors.affiliation: Vector-borne Disease Laboratories, Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana, USA.
authors.forename: Piyanate
authors.initials: P
authors.lastname: Sunyakumthorn
authors.affiliation: Vector-borne Disease Laboratories, Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana, USA.
authors.forename: Kaikhushroo H
authors.initials: KH
authors.lastname: Banajee
authors.affiliation: Vector-borne Disease Laboratories, Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana, USA.
authors.forename: Victoria I
authors.initials: VI
authors.lastname: Verhoeve
authors.affiliation: Vector-borne Disease Laboratories, Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana, USA.
authors.forename: Michael T
authors.initials: MT
authors.lastname: Kearney
authors.affiliation: Vector-borne Disease Laboratories, Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana, USA.
authors.forename: Kevin R
authors.initials: KR
authors.lastname: Macaluso
mesh_terms: D008841:Actin Cytoskeleton / Q000235:genetics / Q000378:metabolism; D051376:Actin-Related Protein 2-3 Complex / Q000235:genetics / Q000378:metabolism; D000818:Animals; D060829:Arthropod Proteins / Q000235:genetics* / Q000378:metabolism; D003870:Dermacentor / Q000235:genetics* / Q000378:metabolism / Q000382:microbiology; D057075:Enzyme Assays; D051416:Focal Adhesion Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation; D054884:Host-Pathogen Interactions; D019869:Phosphatidylinositol 3-Kinases / Q000235:genetics / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism; D012281:Rickettsia / Q000502:physiology*; D015398:Signal Transduction; D051316:Wiskott-Aldrich Syndrome Protein / Q000235:genetics / Q000378:metabolism; D020830:rac1 GTP-Binding Protein / Q000235:genetics / Q000378:metabolism; D019061:src-Family Kinases / Q000235:genetics / Q000378:metabolism
chemical_list: D051376:Actin-Related Protein 2-3 Complex; D060829:Arthropod Proteins; D051316:Wiskott-Aldrich Syndrome Protein; D019869:Phosphatidylinositol 3-Kinases; D011505:Protein-Tyrosine Kinases; D051416:Focal Adhesion Protein-Tyrosine Kinases; D019061:src-Family Kinases; D020830:rac1 GTP-Binding Protein