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Structure of a Protozoan Virus from the Human Genitourinary Parasite Trichomonas vaginalis

The flagellated protozoan Trichomonas vaginalis is an obligate human genitourinary parasite and the most frequent cause of sexually transmitted disease worldwide. Most clinical isolates of T. vaginalis are persistently infected with one or more double-stranded RNA (dsRNA) viruses from the genus Tric...

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Autores principales: Parent, Kristin N., Takagi, Yuko, Cardone, Giovanni, Olson, Norman H., Ericsson, Maria, Yang, May, Lee, Yujin, Asara, John M., Fichorova, Raina N., Baker, Timothy S., Nibert, Max L.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Society of Microbiology 2013
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3622925/
https://www.ncbi.nlm.nih.gov/pubmed/23549915
http://dx.doi.org/10.1128/mBio.00056-13
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author Parent, Kristin N.
Takagi, Yuko
Cardone, Giovanni
Olson, Norman H.
Ericsson, Maria
Yang, May
Lee, Yujin
Asara, John M.
Fichorova, Raina N.
Baker, Timothy S.
Nibert, Max L.
author_facet Parent, Kristin N.
Takagi, Yuko
Cardone, Giovanni
Olson, Norman H.
Ericsson, Maria
Yang, May
Lee, Yujin
Asara, John M.
Fichorova, Raina N.
Baker, Timothy S.
Nibert, Max L.
author_sort Parent, Kristin N.
collection PubMed
description The flagellated protozoan Trichomonas vaginalis is an obligate human genitourinary parasite and the most frequent cause of sexually transmitted disease worldwide. Most clinical isolates of T. vaginalis are persistently infected with one or more double-stranded RNA (dsRNA) viruses from the genus Trichomonasvirus, family Totiviridae, which appear to influence not only protozoan biology but also human disease. Here we describe the three-dimensional structure of Trichomonas vaginalis virus 1 (TVV1) virions, as determined by electron cryomicroscopy and icosahedral image reconstruction. The structure reveals a T = 1 capsid comprising 120 subunits, 60 in each of two nonequivalent positions, designated A and B, as previously observed for fungal Totiviridae family members. The putative protomer is identified as an asymmetric AB dimer consistent with either decamer or tetramer assembly intermediates. The capsid surface is notable for raised plateaus around the icosahedral 5-fold axes, with canyons connecting the 2- and 3-fold axes. Capsid-spanning channels at the 5-fold axes are unusually wide and may facilitate release of the viral genome, promoting dsRNA-dependent immunoinflammatory responses, as recently shown upon the exposure of human cervicovaginal epithelial cells to either TVV-infected T. vaginalis or purified TVV1 virions. Despite extensive sequence divergence, conservative features of the capsid reveal a helix-rich fold probably derived from an ancestor shared with fungal Totiviridae family members. Also notable are mass spectrometry results assessing the virion proteins as a complement to structure determination, which suggest that translation of the TVV1 RNA-dependent RNA polymerase in fusion with its capsid protein involves −2, and not +1, ribosomal frameshifting, an uncommonly found mechanism to date.
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spelling pubmed-36229252013-04-12 Structure of a Protozoan Virus from the Human Genitourinary Parasite Trichomonas vaginalis Parent, Kristin N. Takagi, Yuko Cardone, Giovanni Olson, Norman H. Ericsson, Maria Yang, May Lee, Yujin Asara, John M. Fichorova, Raina N. Baker, Timothy S. Nibert, Max L. mBio Research Article The flagellated protozoan Trichomonas vaginalis is an obligate human genitourinary parasite and the most frequent cause of sexually transmitted disease worldwide. Most clinical isolates of T. vaginalis are persistently infected with one or more double-stranded RNA (dsRNA) viruses from the genus Trichomonasvirus, family Totiviridae, which appear to influence not only protozoan biology but also human disease. Here we describe the three-dimensional structure of Trichomonas vaginalis virus 1 (TVV1) virions, as determined by electron cryomicroscopy and icosahedral image reconstruction. The structure reveals a T = 1 capsid comprising 120 subunits, 60 in each of two nonequivalent positions, designated A and B, as previously observed for fungal Totiviridae family members. The putative protomer is identified as an asymmetric AB dimer consistent with either decamer or tetramer assembly intermediates. The capsid surface is notable for raised plateaus around the icosahedral 5-fold axes, with canyons connecting the 2- and 3-fold axes. Capsid-spanning channels at the 5-fold axes are unusually wide and may facilitate release of the viral genome, promoting dsRNA-dependent immunoinflammatory responses, as recently shown upon the exposure of human cervicovaginal epithelial cells to either TVV-infected T. vaginalis or purified TVV1 virions. Despite extensive sequence divergence, conservative features of the capsid reveal a helix-rich fold probably derived from an ancestor shared with fungal Totiviridae family members. Also notable are mass spectrometry results assessing the virion proteins as a complement to structure determination, which suggest that translation of the TVV1 RNA-dependent RNA polymerase in fusion with its capsid protein involves −2, and not +1, ribosomal frameshifting, an uncommonly found mechanism to date. American Society of Microbiology 2013-04-02 /pmc/articles/PMC3622925/ /pubmed/23549915 http://dx.doi.org/10.1128/mBio.00056-13 Text en Copyright © 2013 Parent et al. http://creativecommons.org/licenses/by-nc-sa/3.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution-Noncommercial-ShareAlike 3.0 Unported (http://creativecommons.org/licenses/by-nc-sa/3.0/) license, which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original author and source are credited.
spellingShingle Research Article
Parent, Kristin N.
Takagi, Yuko
Cardone, Giovanni
Olson, Norman H.
Ericsson, Maria
Yang, May
Lee, Yujin
Asara, John M.
Fichorova, Raina N.
Baker, Timothy S.
Nibert, Max L.
Structure of a Protozoan Virus from the Human Genitourinary Parasite Trichomonas vaginalis
title Structure of a Protozoan Virus from the Human Genitourinary Parasite Trichomonas vaginalis
title_full Structure of a Protozoan Virus from the Human Genitourinary Parasite Trichomonas vaginalis
title_fullStr Structure of a Protozoan Virus from the Human Genitourinary Parasite Trichomonas vaginalis
title_full_unstemmed Structure of a Protozoan Virus from the Human Genitourinary Parasite Trichomonas vaginalis
title_short Structure of a Protozoan Virus from the Human Genitourinary Parasite Trichomonas vaginalis
title_sort structure of a protozoan virus from the human genitourinary parasite trichomonas vaginalis
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3622925/
https://www.ncbi.nlm.nih.gov/pubmed/23549915
http://dx.doi.org/10.1128/mBio.00056-13
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