Badie, C., Yáñez-Muñoz, R. J., Muller, C., Salles, B. and Porter, A. C. (2008) Impaired telomerase activity in human cells expressing GFP-Ku86 fusion proteins. Cytogenetic and Genome Research, 122 (3-4).
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The Ku heterodimer is a DNA end-binding protein that promotes the non-homologous end joining (NHEJ) pathway of DNA double strand break (DSB) repair by recruiting the catalytic subunit of the DNA-dependent protein kinase (DNA-PKcs). Ku is also a normal component of telomeres where it is required for telomere maintenance, interacting not only with the DNA but also with various telomere proteins including telomerase. The way in which Ku simultaneously plays such distinct roles, end-joining at DSBs and end-maintenance at telomeres, is unclear. One way to address this is to study cells in which the NHEJ and telomeric roles of Ku have been separated. Here we describe human cells that express fusions between the large human Ku subunit (Ku86) and a fluorescent protein tag. These cells have reduced telomerase activity and increased sensitivity to ionizing radiation (IR) but no change in their DNA-PK activity or in the DNA end-binding of endogenous Ku. Cells with particularly large amounts of one fusion protein undergo progressive telomere shortening and cellular senescence. These data are consistent with models in which Ku recruits telomerase to telomeres or activates recruited telomerase and suggest that the Ku86 fusion proteins specifically block this role.
This is a Submitted version This version's date is: 2008 This item is not peer reviewed
https://repository.royalholloway.ac.uk/items/598335c3-9523-3c79-030b-9fd54c83a938/1/
Deposited by Research Information System (atira) on 05-Jun-2012 in Royal Holloway Research Online.Last modified on 05-Jun-2012
Badie, C Yanez-Munoz, R J Muller, C Salles, B Porter, A C G Medical Research Council/United Kingdom Research Support, Non-U.S. Gov't Switzerland Cytogenetic and genome research Cytogenet Genome Res. 2008;122(3-4):326-35. Epub 2009 Jan 30.