Skip Navigation

Nucleic Acids Research 2005 33(14):4536-4543; doi:10.1093/nar/gki769
This Article
Right arrow Full Text Freely available
Right arrow Print PDF (860K) Freely available
Right arrow Screen PDF (359K) Freely available
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Search for citing articles in:
ISI Web of Science (9)
Right arrow Commercial Re-use Guidelines
for Open Access NAR Content
Google Scholar
Right arrow Articles by Dreesen, O.
Right arrow Articles by Cross, G. A. M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Dreesen, O.
Right arrow Articles by Cross, G. A. M.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Published online 9 August 2005

© The Author 2005. Published by Oxford University Press. All rights reserved
The online version of this article has been published under an open access model. Users are entitled to use, reproduce, disseminate, or display the open access version of this article for non-commercial purposes provided that: the original authorship is properly and fully attributed; the Journal and Oxford University Press are attributed as the original place of publication with the correct citation details given; if an article is subsequently reproduced or disseminated not in its entirety but only in part or as a derivative work this must be clearly indicated. For commercial re-use, please contact journals.permissions{at}oupjournals.org

Article

Telomere structure and shortening in telomerase-deficient Trypanosoma brucei

Oliver Dreesen, Bibo Li and George A. M. Cross*

Laboratory of Molecular Parasitology, The Rockefeller University 1230 York Avenue, NY 10021-6399, USA

*To whom correspondence should be addressed. Tel: +1 212 327 7571; Fax: +1 212 3277845; Email: george.cross{at}rockefeller.edu

Received July 27, 2005. Accepted July 28, 2005.

Telomerase consists of a reverse transcriptase (TERT) and an RNA that contains a template for telomere-repeat extension. Telomerase is required to prevent telomere erosion and its activity or lack thereof is important for tumorigenesis and ageing. Telomerase has been identified in numerous organisms but it has not been studied in kinetoplastid protozoa. Trypanosoma brucei, the causative agent of African sleeping sickness, evades the host immune response by frequently changing its variant surface glycoprotein (VSG). The single expressed VSG is transcribed from one of ~20 subtelomeric ‘Expression Sites’, but the role telomeres might play in regulating VSG transcription and switching is unknown. We identified and sequenced the T.brucei TERT gene. Deleting TERT resulted in progressive telomere shortening of 3–6 bp per generation. In other organisms, the rate of telomere shortening is proportional to the length of the terminal 3' single-strand overhang. In T.brucei, G-overhangs were undetectable (<30 nt) by in-gel hybridization. The rate of telomere shortening therefore, agrees with the predicted shortening due to the end replication problem, and is consistent with our observation that G-overhangs are short. Trypanosomes whose telomere length can be manipulated provide a new tool to investigate the role of telomeres in antigenic variation.

GenBank accession no: AY904042


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 Nucleic Acids ResHome page
L. Glover, S. Alsford, C. Beattie, and D. Horn
Deletion of a trypanosome telomere leads to loss of silencing and progressive loss of terminal DNA in the absence of cell cycle arrest
Nucleic Acids Res., February 16, 2007; 35(3): 872 - 880.
[Abstract] [Full Text] [PDF]

Home page
 Eukaryot CellHome page
O. Dreesen and G. A. M. Cross
Consequences of Telomere Shortening at an Active VSG Expression Site in Telomerase-Deficient Trypanosoma brucei
Eukaryot. Cell, December 1, 2006; 5(12): 2114 - 2119.
[Abstract] [Full Text] [PDF]

Home page
 Mol. Cell. Biol.Home page
O. Dreesen and G. A. M. Cross
Telomerase-Independent Stabilization of Short Telomeres in Trypanosoma brucei.
Mol. Cell. Biol., July 1, 2006; 26(13): 4911 - 4919.
[Abstract] [Full Text] [PDF]


Disclaimer:
Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.