A Novel Secreted Protein, MYR1, Is Central to <italic toggle="yes">Toxoplasma</italic>’s Manipulation of Host Cells

ABSTRACT The intracellular protozoan Toxoplasma gondii dramatically reprograms the transcriptome of host cells it infects, including substantially up-regulating the host oncogene c-myc. By applying a flow cytometry-based selection to infected mouse cells expressing green fluorescent protein fused to...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autores principales:	Magdalena Franco, Michael W. Panas, Nicole D. Marino, Mei-Chong Wendy Lee, Kerry R. Buchholz, Felice D. Kelly, Jeffrey J. Bednarski, Barry P. Sleckman, Nader Pourmand, John C. Boothroyd
Formato:	article
Lenguaje:	EN
Publicado:	American Society for Microbiology 2016
Materias:	Microbiology QR1-502
Acceso en línea:	https://doaj.org/article/243b6c43649744e1bef00a449c4e984f
Etiquetas:	Agregar Etiqueta Sin Etiquetas, Sea el primero en etiquetar este registro!

id	oai:doaj.org-article:243b6c43649744e1bef00a449c4e984f
record_format	dspace
spelling	oai:doaj.org-article:243b6c43649744e1bef00a449c4e984f2021-11-15T15:49:39ZA Novel Secreted Protein, MYR1, Is Central to <italic toggle="yes">Toxoplasma</italic>’s Manipulation of Host Cells10.1128/mBio.02231-152150-7511https://doaj.org/article/243b6c43649744e1bef00a449c4e984f2016-03-01T00:00:00Zhttps://journals.asm.org/doi/10.1128/mBio.02231-15https://doaj.org/toc/2150-7511ABSTRACT The intracellular protozoan Toxoplasma gondii dramatically reprograms the transcriptome of host cells it infects, including substantially up-regulating the host oncogene c-myc. By applying a flow cytometry-based selection to infected mouse cells expressing green fluorescent protein fused to c-Myc (c-Myc–GFP), we isolated mutant tachyzoites defective in this host c-Myc up-regulation. Whole-genome sequencing of three such mutants led to the identification of MYR1 (Myc regulation 1; TGGT1_254470) as essential for c-Myc induction. MYR1 is a secreted protein that requires TgASP5 to be cleaved into two stable portions, both of which are ultimately found within the parasitophorous vacuole and at the parasitophorous vacuole membrane. Deletion of MYR1 revealed that in addition to its requirement for c-Myc up-regulation, the MYR1 protein is needed for the ability of Toxoplasma tachyzoites to modulate several other important host pathways, including those mediated by the dense granule effectors GRA16 and GRA24. This result, combined with its location at the parasitophorous vacuole membrane, suggested that MYR1 might be a component of the machinery that translocates Toxoplasma effectors from the parasitophorous vacuole into the host cytosol. Support for this possibility was obtained by showing that transit of GRA24 to the host nucleus is indeed MYR1-dependent. As predicted by this pleiotropic phenotype, parasites deficient in MYR1 were found to be severely attenuated in a mouse model of infection. We conclude, therefore, that MYR1 is a novel protein that plays a critical role in how Toxoplasma delivers effector proteins to the infected host cell and that this is crucial to virulence. IMPORTANCE Toxoplasma gondii is an important human pathogen and a model for the study of intracellular parasitism. Infection of the host cell with Toxoplasma tachyzoites involves the introduction of protein effectors, including many that are initially secreted into the parasitophorous vacuole but must ultimately translocate to the host cell cytosol to function. The work reported here identified a novel protein that is required for this translocation. These results give new insight into a very unusual cell biology process as well as providing a potential handle on a pathway that is necessary for virulence and, therefore, a new potential target for chemotherapy.Magdalena FrancoMichael W. PanasNicole D. MarinoMei-Chong Wendy LeeKerry R. BuchholzFelice D. KellyJeffrey J. BednarskiBarry P. SleckmanNader PourmandJohn C. BoothroydAmerican Society for MicrobiologyarticleMicrobiologyQR1-502ENmBio, Vol 7, Iss 1 (2016)
institution	DOAJ
collection	DOAJ
language	EN
topic	Microbiology QR1-502
spellingShingle	Microbiology QR1-502 Magdalena Franco Michael W. Panas Nicole D. Marino Mei-Chong Wendy Lee Kerry R. Buchholz Felice D. Kelly Jeffrey J. Bednarski Barry P. Sleckman Nader Pourmand John C. Boothroyd A Novel Secreted Protein, MYR1, Is Central to <italic toggle="yes">Toxoplasma</italic>’s Manipulation of Host Cells
description	ABSTRACT The intracellular protozoan Toxoplasma gondii dramatically reprograms the transcriptome of host cells it infects, including substantially up-regulating the host oncogene c-myc. By applying a flow cytometry-based selection to infected mouse cells expressing green fluorescent protein fused to c-Myc (c-Myc–GFP), we isolated mutant tachyzoites defective in this host c-Myc up-regulation. Whole-genome sequencing of three such mutants led to the identification of MYR1 (Myc regulation 1; TGGT1_254470) as essential for c-Myc induction. MYR1 is a secreted protein that requires TgASP5 to be cleaved into two stable portions, both of which are ultimately found within the parasitophorous vacuole and at the parasitophorous vacuole membrane. Deletion of MYR1 revealed that in addition to its requirement for c-Myc up-regulation, the MYR1 protein is needed for the ability of Toxoplasma tachyzoites to modulate several other important host pathways, including those mediated by the dense granule effectors GRA16 and GRA24. This result, combined with its location at the parasitophorous vacuole membrane, suggested that MYR1 might be a component of the machinery that translocates Toxoplasma effectors from the parasitophorous vacuole into the host cytosol. Support for this possibility was obtained by showing that transit of GRA24 to the host nucleus is indeed MYR1-dependent. As predicted by this pleiotropic phenotype, parasites deficient in MYR1 were found to be severely attenuated in a mouse model of infection. We conclude, therefore, that MYR1 is a novel protein that plays a critical role in how Toxoplasma delivers effector proteins to the infected host cell and that this is crucial to virulence. IMPORTANCE Toxoplasma gondii is an important human pathogen and a model for the study of intracellular parasitism. Infection of the host cell with Toxoplasma tachyzoites involves the introduction of protein effectors, including many that are initially secreted into the parasitophorous vacuole but must ultimately translocate to the host cell cytosol to function. The work reported here identified a novel protein that is required for this translocation. These results give new insight into a very unusual cell biology process as well as providing a potential handle on a pathway that is necessary for virulence and, therefore, a new potential target for chemotherapy.
format	article
author	Magdalena Franco Michael W. Panas Nicole D. Marino Mei-Chong Wendy Lee Kerry R. Buchholz Felice D. Kelly Jeffrey J. Bednarski Barry P. Sleckman Nader Pourmand John C. Boothroyd
author_facet	Magdalena Franco Michael W. Panas Nicole D. Marino Mei-Chong Wendy Lee Kerry R. Buchholz Felice D. Kelly Jeffrey J. Bednarski Barry P. Sleckman Nader Pourmand John C. Boothroyd
author_sort	Magdalena Franco
title	A Novel Secreted Protein, MYR1, Is Central to <italic toggle="yes">Toxoplasma</italic>’s Manipulation of Host Cells
title_short	A Novel Secreted Protein, MYR1, Is Central to <italic toggle="yes">Toxoplasma</italic>’s Manipulation of Host Cells
title_full	A Novel Secreted Protein, MYR1, Is Central to <italic toggle="yes">Toxoplasma</italic>’s Manipulation of Host Cells
title_fullStr	A Novel Secreted Protein, MYR1, Is Central to <italic toggle="yes">Toxoplasma</italic>’s Manipulation of Host Cells
title_full_unstemmed	A Novel Secreted Protein, MYR1, Is Central to <italic toggle="yes">Toxoplasma</italic>’s Manipulation of Host Cells
title_sort	novel secreted protein, myr1, is central to <italic toggle="yes">toxoplasma</italic>’s manipulation of host cells
publisher	American Society for Microbiology
publishDate	2016
url	https://doaj.org/article/243b6c43649744e1bef00a449c4e984f
work_keys_str_mv	AT magdalenafranco anovelsecretedproteinmyr1iscentraltoitalictoggleyestoxoplasmaitalicsmanipulationofhostcells AT michaelwpanas anovelsecretedproteinmyr1iscentraltoitalictoggleyestoxoplasmaitalicsmanipulationofhostcells AT nicoledmarino anovelsecretedproteinmyr1iscentraltoitalictoggleyestoxoplasmaitalicsmanipulationofhostcells AT meichongwendylee anovelsecretedproteinmyr1iscentraltoitalictoggleyestoxoplasmaitalicsmanipulationofhostcells AT kerryrbuchholz anovelsecretedproteinmyr1iscentraltoitalictoggleyestoxoplasmaitalicsmanipulationofhostcells AT felicedkelly anovelsecretedproteinmyr1iscentraltoitalictoggleyestoxoplasmaitalicsmanipulationofhostcells AT jeffreyjbednarski anovelsecretedproteinmyr1iscentraltoitalictoggleyestoxoplasmaitalicsmanipulationofhostcells AT barrypsleckman anovelsecretedproteinmyr1iscentraltoitalictoggleyestoxoplasmaitalicsmanipulationofhostcells AT naderpourmand anovelsecretedproteinmyr1iscentraltoitalictoggleyestoxoplasmaitalicsmanipulationofhostcells AT johncboothroyd anovelsecretedproteinmyr1iscentraltoitalictoggleyestoxoplasmaitalicsmanipulationofhostcells AT magdalenafranco novelsecretedproteinmyr1iscentraltoitalictoggleyestoxoplasmaitalicsmanipulationofhostcells AT michaelwpanas novelsecretedproteinmyr1iscentraltoitalictoggleyestoxoplasmaitalicsmanipulationofhostcells AT nicoledmarino novelsecretedproteinmyr1iscentraltoitalictoggleyestoxoplasmaitalicsmanipulationofhostcells AT meichongwendylee novelsecretedproteinmyr1iscentraltoitalictoggleyestoxoplasmaitalicsmanipulationofhostcells AT kerryrbuchholz novelsecretedproteinmyr1iscentraltoitalictoggleyestoxoplasmaitalicsmanipulationofhostcells AT felicedkelly novelsecretedproteinmyr1iscentraltoitalictoggleyestoxoplasmaitalicsmanipulationofhostcells AT jeffreyjbednarski novelsecretedproteinmyr1iscentraltoitalictoggleyestoxoplasmaitalicsmanipulationofhostcells AT barrypsleckman novelsecretedproteinmyr1iscentraltoitalictoggleyestoxoplasmaitalicsmanipulationofhostcells AT naderpourmand novelsecretedproteinmyr1iscentraltoitalictoggleyestoxoplasmaitalicsmanipulationofhostcells AT johncboothroyd novelsecretedproteinmyr1iscentraltoitalictoggleyestoxoplasmaitalicsmanipulationofhostcells
_version_	1718427447262707712

A Novel Secreted Protein, MYR1, Is Central to <italic toggle="yes">Toxoplasma</italic>’s Manipulation of Host Cells

Ejemplares similares