Conway, Colin and McCulloch, Richard and Ginger, Michael L. and Robinson, Nicholas P. and Browitt, Alison and Barry, J. David (2002) Ku Is Important for Telomere Maintenance, but Not for Differential Expression of Telomeric VSG Genes, in African Trypanosomes. Journal of Biological Chemistry, 277 (24). pp. 21269-21277.Full text not available from this repository.
Trypanosome antigenic variation, involving differential expression of variant surface glycoprotein (VSG) genes, has a strong association with telomeres and with DNA recombination. All expressed VSGs are telomeric, and differential activation involves recombination into the telomeric environment or silencing/activation of subtelomeric promoters. A number of pathogen contingency gene systems associated with immune evasion involve telomeric loci, which has prompted speculation that chromosome ends provide conditions conducive for the operation of rapid gene switching mechanisms. Ku is a protein associated with eukaryotic telomeres that is directly involved in DNA recombination and in gene silencing. We have tested the hypothesis that Ku in trypanosomes is centrally involved in differential VSG expression. We show, via the generation of null mutants, that trypanosome Ku is closely involved in telomere length maintenance, more so for a transcriptionally active than an inactive telomere, but exhibits no detectable influence on DNA double strand break repair. The absence of Ku and the consequent great shortening of telomeres had no detectable influence either on the rate of VSG switching or on the silencing of the telomeric promoters of the VSG subset that is expressed in the tsetse fly.
|Journal or Publication Title:||Journal of Biological Chemistry|
|Subjects:||Q Science > QH Natural history > QH301 Biology|
|Departments:||Faculty of Health and Medicine > Biomedical & Life Sciences|
Faculty of Science and Technology > Mathematics and Statistics
|Deposited By:||Dr Michael Ginger|
|Deposited On:||17 Jun 2008 15:07|
|Last Modified:||26 Jul 2012 18:40|
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