This Article Full Text Full Text (PDF) Supplemental material Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Schimanski, B. Articles by Günzl, A. Search for Related Content PubMed PubMed Citation Articles by Schimanski, B. Articles by Günzl, A.

Characterization of a Multisubunit Transcription Factor Complex Essential for Spliced-Leader RNA Gene Transcription in Trypanosoma brucei

Department of Genetics and Developmental Biology and Department of Molecular, Microbial, and Structural Biology, University of Connecticut Health Center, 263 Farmington Avenue, Farmington, Connecticut 06030-3710

Received 15 March 2005/ Returned for modification 28 April 2005/ Accepted 20 May 2005

In the unicellular human parasites Trypanosoma brucei, Trypanosoma cruzi, and Leishmania spp., the spliced-leader (SL) RNA is a key molecule in gene expression donating its 5'-terminal region in SL addition trans splicing of nuclear pre-mRNA. While there is no evidence that this process exists in mammals, it is obligatory in mRNA maturation of trypanosomatid parasites. Hence, throughout their life cycle, these organisms crucially depend on high levels of SL RNA synthesis. As putative SL RNA gene transcription factors, a partially characterized small nuclear RNA-activating protein complex (SNAP_c) and the TATA-binding protein related factor 4 (TRF4) have been identified thus far. Here, by tagging TRF4 with a novel epitope combination termed PTP, we tandem affinity purified from crude T. brucei extracts a stable and transcriptionally active complex of six proteins. Besides TRF4 these were identified as extremely divergent subunits of SNAP_c and of transcription factor IIA (TFIIA). The latter finding was unexpected since genome databases of trypanosomatid parasites appeared to lack general class II transcription factors. As we demonstrate, the TRF4/SNAP_c/TFIIA complex binds specifically to the SL RNA gene promoter upstream sequence element and is absolutely essential for SL RNA gene transcription in vitro.

Supplemental material for this article may be found at http://mcb.asm.org/.

This article has been cited by other articles:

• Das, A., Banday, M., Bellofatto, V. (2008). RNA Polymerase Transcription Machinery in Trypanosomes. Eukaryot Cell 7: 429-434 [Full Text]  
• Nguyen, T. N., Schimanski, B., Gunzl, A. (2007). Active RNA Polymerase I of Trypanosoma brucei Harbors a Novel Subunit Essential for Transcription. Mol. Cell. Biol. 27: 6254-6263 [Abstract] [Full Text]  
• Lee, J. H., Nguyen, T. N., Schimanski, B., Gunzl, A. (2007). Spliced Leader RNA Gene Transcription in Trypanosoma brucei Requires Transcription Factor TFIIH. Eukaryot Cell 6: 641-649 [Abstract] [Full Text]  
• Takebe, S., Witola, W. H., Schimanski, B., Gunzl, A., Ben Mamoun, C. (2007). Purification of Components of the Translation Elongation Factor Complex of Plasmodium falciparum by Tandem Affinity Purification. Eukaryot Cell 6: 584-591 [Abstract] [Full Text]  
• Hernandez, G. Jr, Valafar, F., Stumph, W. E. (2007). Insect small nuclear RNA gene promoters evolve rapidly yet retain conserved features involved in determining promoter activity and RNA polymerase specificity. Nucleic Acids Res 35: 21-34 [Abstract] [Full Text]  
• Jawdekar, G. W., Hanzlowsky, A., Hovde, S. L., Jelencic, B., Feig, M., Geiger, J. H., Henry, R. W. (2006). The Unorthodox SNAP50 Zinc Finger Domain Contributes to Cooperative Promoter Recognition by Human SNAPC. J. Biol. Chem. 281: 31050-31060 [Abstract] [Full Text]  
• Schimanski, B., Brandenburg, J., Nguyen, T. N., Caimano, M. J., Gunzl, A. (2006). A TFIIB-like protein is indispensable for spliced leader RNA gene transcription in Trypanosoma brucei. Nucleic Acids Res 34: 1676-1684 [Abstract] [Full Text]  
• Palenchar, J. B., Liu, W., Palenchar, P. M., Bellofatto, V. (2006). A Divergent Transcription Factor TFIIB in Trypanosomes Is Required for RNA Polymerase II-Dependent Spliced Leader RNA Transcription and Cell Viability. Eukaryot Cell 5: 293-300 [Abstract] [Full Text]