title: An aspartyl protease defines a novel pathway for export of Toxoplasma proteins into the host cell.
abstract: Infection by Toxoplasma gondii leads to massive changes to the host cell. Here, we identify a novel host cell effector export pathway that requires the Golgi-resident aspartyl protease 5 (ASP5). We demonstrate that ASP5 cleaves a highly constrained amino acid motif that has similarity to the PEXEL-motif of Plasmodium parasites. We show that ASP5 matures substrates at both the N- and C-terminal ends of proteins and also controls trafficking of effectors without this motif. Furthermore, ASP5 controls establishment of the nanotubular network and is required for the efficient recruitment of host mitochondria to the vacuole. Assessment of host gene expression reveals that the ASP5-dependent pathway influences thousands of the transcriptional changes that Toxoplasma imparts on its host cell. All these changes result in attenuation of virulence of Δasp5 tachyzoites in vivo. This work characterizes the first identified machinery required for export of Toxoplasma effectors into the infected host cell.
authors.affiliation: The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.|Department of Medical Biology, The University of Melbourne, Melbourne, Australia.
authors.forename: Michael J
authors.identifier: http://orcid.org/0000-0002-8025-4558
authors.initials: MJ
authors.lastname: Coffey
authors.affiliation: The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.|Department of Medical Biology, The University of Melbourne, Melbourne, Australia.
authors.forename: Brad E
authors.identifier: http://orcid.org/0000-0001-9117-1048
authors.initials: BE
authors.lastname: Sleebs
authors.affiliation: The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.|Department of Medical Biology, The University of Melbourne, Melbourne, Australia.
authors.forename: Alessandro D
authors.initials: AD
authors.lastname: Uboldi
authors.affiliation: The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.|Department of Medical Biology, The University of Melbourne, Melbourne, Australia.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Garnham
authors.affiliation: Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, United States.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Franco
authors.affiliation: Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, United States.
authors.forename: Nicole D
authors.initials: ND
authors.lastname: Marino
authors.affiliation: Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, United States.
authors.forename: Michael W
authors.initials: MW
authors.lastname: Panas
authors.affiliation: Nuffield Department of Clinical Laboratory Science, Oxford University, John Radcliffe Hospital, Oxford, United Kingdom.
authors.forename: David Jp
authors.identifier: http://orcid.org/0000-0001-5045-819X
authors.initials: DJ
authors.lastname: Ferguson
authors.affiliation: La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Australia.
authors.forename: Marta
authors.initials: M
authors.lastname: Enciso
authors.affiliation: The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.
authors.forename: Matthew T
authors.initials: MT
authors.lastname: O'Neill
authors.affiliation: The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.
authors.forename: Sash
authors.initials: S
authors.lastname: Lopaticki
authors.affiliation: The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.|Department of Medical Biology, The University of Melbourne, Melbourne, Australia.
authors.forename: Rebecca J
authors.initials: RJ
authors.lastname: Stewart
authors.affiliation: The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.|Department of Medical Biology, The University of Melbourne, Melbourne, Australia.
authors.forename: Grant
authors.initials: G
authors.lastname: Dewson
authors.affiliation: The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.|Department of Mathematics and Statistics, The University of Melbourne, Melbourne, Australia.
authors.forename: Gordon K
authors.identifier: http://orcid.org/0000-0001-9221-2892
authors.initials: GK
authors.lastname: Smyth
authors.affiliation: La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Australia.
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Smith
authors.affiliation: The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.|Department of Medical Biology, The University of Melbourne, Melbourne, Australia.
authors.forename: Seth L
authors.initials: SL
authors.lastname: Masters
authors.affiliation: Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, United States.
authors.forename: John C
authors.initials: JC
authors.lastname: Boothroyd
authors.affiliation: The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.|Department of Medical Biology, The University of Melbourne, Melbourne, Australia.
authors.forename: Justin A
authors.identifier: http://orcid.org/0000-0001-7322-2040
authors.initials: JA
authors.lastname: Boddey
authors.affiliation: The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.|Department of Medical Biology, The University of Melbourne, Melbourne, Australia.
authors.forename: Christopher J
authors.identifier: http://orcid.org/0000-0002-7036-6222
authors.initials: CJ
authors.lastname: Tonkin
mesh_terms: D057055:Aspartic Acid Proteases / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D005347:Fibroblasts / Q000469:parasitology; D017353:Gene Deletion; D006801:Humans; D011499:Protein Processing, Post-Translational; D021381:Protein Transport; D015800:Protozoan Proteins / Q000378:metabolism*; D014122:Toxoplasma / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism*; D014774:Virulence; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D015800:Protozoan Proteins; D037521:Virulence Factors; D057055:Aspartic Acid Proteases
keywords: Toxoplasma; effector; export; infectious disease; microbiology; protease