Eukaryotic Cell
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Günzl, A.
Right arrow Articles by Lee, M. G.-S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Günzl, A.
Right arrow Articles by Lee, M. G.-S.
Eukaryotic Cell, June 2003, p. 542-551, Vol. 2, No. 3
1535-9778/03/$08.00+0     DOI: 10.1128/EC.2.3.542-551.2003
Copyright © 2003, American Society for Microbiology. All Rights Reserved.

RNA Polymerase I Transcribes Procyclin Genes and Variant Surface Glycoprotein Gene Expression Sites in Trypanosoma brucei

Arthur Günzl,1 Thomas Bruderer,2 Gabriele Laufer,1 Bernd Schimanski,1 Lan-Chun Tu,2 Hui-Min Chung,3 Pei-Tseng Lee,2 and Mary Gwo-Shu Lee2*

Medizinisch-Naturwissenschaftliches Forschungsinstitut der Universität Tübingen, 72074 Tübingen, Germany,1 Department of Pathology, New York University School of Medicine, New York, New York 10016,2 Department of Genetic and Development, Columbia University, New York, New York 100323

Received 17 October 2002/ Accepted 18 March 2003

In eukaryotes, RNA polymerase (pol) I exclusively transcribes the large rRNA gene unit (rDNA) and mRNA is synthesized by RNA pol II. The African trypanosome, Trypanosoma brucei, represents an exception to this rule. In this organism, transcription of genes encoding the variant surface glycoprotein (VSG) and the procyclins is resistant to {alpha}-amanitin, indicating that it is mediated by RNA pol I, while other protein-coding genes are transcribed by RNA pol II. To obtain firm proof for this concept, we generated a T. brucei cell line which exclusively expresses protein C epitope-tagged RNA pol I. Using an anti-protein C immunoaffinity matrix, we specifically depleted RNA pol I from transcriptionally active cell extracts. The depletion of RNA pol I impaired in vitro transcription initiated at the rDNA promoter, the GPEET procyclin gene promoter, and a VSG gene expression site promoter but did not affect transcription from the spliced leader (SL) RNA gene promoter. Fittingly, induction of RNA interference against the RNA pol I largest subunit in insect-form trypanosomes significantly reduced the relative transcriptional efficiency of rDNA, procyclin genes, and VSG expression sites in vivo whereas that of SL RNA, {alpha}ß-tubulin, and heat shock protein 70 genes was not affected. Our studies unequivocally show that T. brucei harbors a multifunctional RNA pol I which, in addition to transcribing rDNA, transcribes procyclin genes and VSG gene expression sites.

* Corresponding author. Mailing address: Department of Pathology, New York University School of Medicine, 550 First Ave., New York, NY 10016. Phone: (212) 263-8260. Fax: (212) 263-8179. E-mail: leeg02{at}med.nyu.edu.

Eukaryotic Cell, June 2003, p. 542-551, Vol. 2, No. 3
1535-9778/03/$08.00+0     DOI: 10.1128/EC.2.3.542-551.2003
Copyright © 2003, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:



HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Appl. Environ. Microbiol. Infect. Immun. J. Bacteriol.
Mol. Cell Biol. Microbiol. Mol. Biol. Rev. ALL ASM JOURNALS
Copyright © 2003 by the American Society for Microbiology.