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Inhibition of telomerase RNA decay rescues telomerase deficiency caused by dyskerin or PARN defects

Nature Structural & Molecular Biology volume 23, pages 286292 (2016) | Download Citation



Mutations in the human telomerase RNA component (hTR), the telomerase ribonucleoprotein component dyskerin (DKC1) and the poly(A) RNase (PARN) can lead to reduced levels of hTR and to dyskeratosis congenita (DC). However, the enzymes and mechanisms responsible for hTR degradation are unknown. We demonstrate that defects in dyskerin binding lead to hTR degradation by PAPD5-mediated oligoadenylation, which promotes 3′-to-5′ degradation by EXOSC10, as well as decapping and 5′-to-3′ decay by the cytoplasmic DCP2 and XRN1 enzymes. PARN increased hTR levels by deadenylating hTR, thereby limiting its degradation by EXOSC10. Telomerase activity and proper hTR localization in dyskerin- or PARN-deficient cells were rescued by knockdown of DCP2 and/or EXOSC10. Prevention of hTR RNA decay also led to a rescue of localization of DC-associated hTR mutants. These results suggest that inhibition of RNA decay pathways might be a useful therapy for some telomere pathologies.

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We would like to thank A. Zaug for his assistance with the telomerase direct activity assays; A. Webb for help with the illustrations and figures in this manuscript; S. Spencer (University of Colorado Boulder), J. Lingner (Institut Suisse de Recherche Expérimentale sur le Cancer) and S.B. Cohen (Children's Medical Research Institute) for providing materials; and members of the Parker and Cech laboratories for their comments and suggestions. J.C.S. is supported as a Merck fellow of the Damon Runyon Cancer Research Foundation (DRG-2169-13). This work was supported by US National Institutes of Health grants R01 GM45443 (R.P.) and GM099705 (T.R.C.). T.R.C. and R.P. are supported as investigators of the Howard Hughes Medical Institute.

Author information


  1. Department of Chemistry & Biochemistry, University of Colorado, Boulder, Colorado, USA.

    • Siddharth Shukla
    • , Jens C Schmidt
    • , Katherine C Goldfarb
    • , Thomas R Cech
    •  & Roy Parker
  2. Howard Hughes Medical Institute, Chevy Chase, Maryland, USA.

    • Thomas R Cech
    •  & Roy Parker


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S.S., J.C.S., T.R.C. and R.P. conceptualized and designed the experiments. S.S. performed the experiments. J.C.S. performed the Pol II ChIP for hTR. K.C.G. and S.S. analyzed the hTR 3′-end sequencing reads. S.S., J.C.S., T.R.C. and R.P. analyzed and interpreted data. S.S., J.C.S., T.R.C. and R.P. wrote the manuscript.

Competing interests

T.R.C. is on the board of directors of Merck, Inc. The other authors declare no competing financial interests.

Corresponding author

Correspondence to Roy Parker.

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    Supplementary Text and Figures

    Supplementary Figures 1–4

  2. 2.

    Supplementary Data Set 1

    Uncropped blots and autoradiograph images

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    Supplementary Table 1

    Raw data for hTR 3′ end sequencing under different conditions

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    Supplementary Table 2

    Compiled number of reads for hTR 3′ end sequencing

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