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Antigenic variation in African trypanosomes
Studies on Variant Surface Glycoproteins (VSGs) and antigenic variation in the African trypanosome, Trypanosoma brucei, have yielded a remarkable range of novel and important insights. The features first identified in T. brucei extend from unique to conserved-among-trypanosomatids to conserved-among...
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Formato: | Online Artículo Texto |
Lenguaje: | English |
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Elsevier/North-Holland Biomedical Press
2014
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4155160/ https://www.ncbi.nlm.nih.gov/pubmed/24859277 http://dx.doi.org/10.1016/j.molbiopara.2014.05.001 |
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author | Horn, David |
author_facet | Horn, David |
author_sort | Horn, David |
collection | PubMed |
description | Studies on Variant Surface Glycoproteins (VSGs) and antigenic variation in the African trypanosome, Trypanosoma brucei, have yielded a remarkable range of novel and important insights. The features first identified in T. brucei extend from unique to conserved-among-trypanosomatids to conserved-among-eukaryotes. Consequently, much of what we now know about trypanosomatid biology and much of the technology available has its origin in studies related to VSGs. T. brucei is now probably the most advanced early branched eukaryote in terms of experimental tractability and can be approached as a pathogen, as a model for studies on fundamental processes, as a model for studies on eukaryotic evolution or often all of the above. In terms of antigenic variation itself, substantial progress has been made in understanding the expression and switching of the VSG coat, while outstanding questions continue to stimulate innovative new approaches. There are large numbers of VSG genes in the genome but only one is expressed at a time, always immediately adjacent to a telomere. DNA repair processes allow a new VSG to be copied into the single transcribed locus. A coordinated transcriptional switch can also allow a new VSG gene to be activated without any detectable change in the DNA sequence, thereby maintaining singular expression, also known as allelic exclusion. I review the story behind VSGs; the genes, their expression and switching, their central role in T. brucei virulence, the discoveries that emerged along the way and the persistent questions relating to allelic exclusion in particular. |
format | Online Article Text |
id | pubmed-4155160 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2014 |
publisher | Elsevier/North-Holland Biomedical Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-41551602014-09-06 Antigenic variation in African trypanosomes Horn, David Mol Biochem Parasitol Review Studies on Variant Surface Glycoproteins (VSGs) and antigenic variation in the African trypanosome, Trypanosoma brucei, have yielded a remarkable range of novel and important insights. The features first identified in T. brucei extend from unique to conserved-among-trypanosomatids to conserved-among-eukaryotes. Consequently, much of what we now know about trypanosomatid biology and much of the technology available has its origin in studies related to VSGs. T. brucei is now probably the most advanced early branched eukaryote in terms of experimental tractability and can be approached as a pathogen, as a model for studies on fundamental processes, as a model for studies on eukaryotic evolution or often all of the above. In terms of antigenic variation itself, substantial progress has been made in understanding the expression and switching of the VSG coat, while outstanding questions continue to stimulate innovative new approaches. There are large numbers of VSG genes in the genome but only one is expressed at a time, always immediately adjacent to a telomere. DNA repair processes allow a new VSG to be copied into the single transcribed locus. A coordinated transcriptional switch can also allow a new VSG gene to be activated without any detectable change in the DNA sequence, thereby maintaining singular expression, also known as allelic exclusion. I review the story behind VSGs; the genes, their expression and switching, their central role in T. brucei virulence, the discoveries that emerged along the way and the persistent questions relating to allelic exclusion in particular. Elsevier/North-Holland Biomedical Press 2014-07 /pmc/articles/PMC4155160/ /pubmed/24859277 http://dx.doi.org/10.1016/j.molbiopara.2014.05.001 Text en © 2014 The Authors https://creativecommons.org/licenses/by/3.0/This work is licensed under a Creative Commons Attribution 3.0 Unported License (https://creativecommons.org/licenses/by/3.0/) . |
spellingShingle | Review Horn, David Antigenic variation in African trypanosomes |
title | Antigenic variation in African trypanosomes |
title_full | Antigenic variation in African trypanosomes |
title_fullStr | Antigenic variation in African trypanosomes |
title_full_unstemmed | Antigenic variation in African trypanosomes |
title_short | Antigenic variation in African trypanosomes |
title_sort | antigenic variation in african trypanosomes |
topic | Review |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4155160/ https://www.ncbi.nlm.nih.gov/pubmed/24859277 http://dx.doi.org/10.1016/j.molbiopara.2014.05.001 |
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