Promoter occupancy of the basal class I transcription factor A differs strongly between active and silent VSG expression sites in Trypanosoma brucei
Please always quote using this URN: urn:nbn:de:bvb:20-opus-117232
- Monoallelic expression within a gene family is found in pathogens exhibiting antigenic variation and in mammalian olfactory neurons. Trypanosoma brucei, a lethal parasite living in the human bloodstream, expresses variant surface glycoprotein (VSG) from 1 of 15 bloodstream expression sites (BESs) by virtue of a multifunctional RNA polymerase I. The active BES is transcribed in an extranucleolar compartment termed the expression site body (ESB), whereas silent BESs, located elsewhere within the nucleus, are repressed epigenetically. TheMonoallelic expression within a gene family is found in pathogens exhibiting antigenic variation and in mammalian olfactory neurons. Trypanosoma brucei, a lethal parasite living in the human bloodstream, expresses variant surface glycoprotein (VSG) from 1 of 15 bloodstream expression sites (BESs) by virtue of a multifunctional RNA polymerase I. The active BES is transcribed in an extranucleolar compartment termed the expression site body (ESB), whereas silent BESs, located elsewhere within the nucleus, are repressed epigenetically. The regulatory mechanisms, however, are poorly understood. Here we show that two essential subunits of the basal class I transcription factor A (CITFA) predominantly occupied the promoter of the active BES relative to that of a silent BES, a phenotype that was maintained after switching BESs in situ. In these experiments, high promoter occupancy of CITFA was coupled to high levels of both promoter-proximal RNA abundance and RNA polymerase I occupancy. Accordingly, fluorescently tagged CITFA-7 was concentrated in the nucleolus and the ESB. Because a ChIP-seq analysis found that along the entire BES, CITFA-7 is specifically enriched only at the promoter, our data strongly indicate that monoallelic BES transcription is activated by a mechanism that functions at the level of transcription initiation.…
Author: | Tu N. Nguyen, Laura S. M. Müller, Sung Hee Park, T. Nicolai Siegel, Arthur Günzl |
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URN: | urn:nbn:de:bvb:20-opus-117232 |
Document Type: | Journal article |
Faculties: | Medizinische Fakultät / Institut für Molekulare Infektionsbiologie |
Language: | English |
Parent Title (English): | Nucleic Acid Research |
ISSN: | 1362-4962 |
Year of Completion: | 2014 |
Volume: | 42 |
Issue: | 5 |
Pagenumber: | 3164-3176 |
Source: | Nucleic Acids Research, 2014, Vol. 42, No. 5, 3164-3176. doi:10.1093/nar/gkt1301 |
DOI: | https://doi.org/10.1093/nar/gkt1301 |
Pubmed Id: | https://pubmed.ncbi.nlm.nih.gov/24353315 |
Sonstige beteiligte Institutionen: | Research Center of Infectious Diseases (ZINF) of the University of Wurzburg, Germany |
Dewey Decimal Classification: | 6 Technik, Medizin, angewandte Wissenschaften / 61 Medizin und Gesundheit / 610 Medizin und Gesundheit |
Tag: | RNA-polymerase-I; acrican trypanosomes; antigenic variation; blood-stream forms; complex; gene expression; plasmodium falciparum; ribosomal RNA; subunit; virulence genes |
Release Date: | 2015/08/17 |
Licence (German): | CC BY-NC: Creative-Commons-Lizenz: Namensnennung, Nicht kommerziell |