Minimized human telomerase maintains telomeres and resolves endogenous roles of H/ACA proteins, TCAB1, and Cajal bodies

Abstract

We dissected the importance of human telomerase biogenesis and trafficking pathways for telomere maintenance. Biological stability of human telomerase RNA (hTR) relies on H/ACA proteins, but other eukaryotes use other RNP assembly pathways. To investigate additional rationale for human telomerase assembly as H/ACA RNP, we developed a minimized cellular hTR. Remarkably, with only binding sites for telomerase reverse transcriptase (TERT), minimized hTR assembled biologically active enzyme. TERT overexpression was required for cellular interaction with minimized hTR, indicating that H/ACA RNP assembly enhances endogenous hTR-TERT interaction. Telomere maintenance by minimized telomerase was unaffected by elimination of the telomerase holoenzyme Cajal body chaperone TCAB1 or the Cajal body scaffold protein Coilin. Surprisingly, wild-type hTR also maintained and elongated telomeres in TCAB1 or Coilin knockout cells, with distinct changes in telomerase action. Overall we elucidate trafficking requirements for telomerase biogenesis and function and expand mechanisms by which altered telomere maintenance engenders human disease.

Article and author information

Author details

  1. Jacob M Vogan

    Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
    Competing interests
    No competing interests declared.
  2. Xiaozhu Zhang

    Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
    Competing interests
    No competing interests declared.
  3. Daniel T Youmans

    Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
    Competing interests
    No competing interests declared.
  4. Samuel G Regalado

    Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
    Competing interests
    No competing interests declared.
  5. Joshua Z Johnson

    Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
    Competing interests
    No competing interests declared.
  6. Dirk Hockemeyer

    Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
    Competing interests
    No competing interests declared.
  7. Kathleen Collins

    Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
    For correspondence
    kcollins@berkeley.edu
    Competing interests
    Kathleen Collins, Reviewing editor, eLife.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-3172-7088

Funding

National Heart, Lung, and Blood Institute (RO1 HL079585)

  • Jacob M Vogan
  • Xiaozhu Zhang
  • Daniel T Youmans
  • Kathleen Collins

Ellison Medical Foundation

  • Samuel G Regalado
  • Joshua Z Johnson
  • Dirk Hockemeyer

Glenn Foundation for Medical Research

  • Samuel G Regalado
  • Joshua Z Johnson
  • Dirk Hockemeyer

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Reviewing Editor

  1. Carol Greider, Johns Hopkins University, United States

Version history

  1. Received: May 26, 2016
  2. Accepted: August 14, 2016
  3. Accepted Manuscript published: August 15, 2016 (version 1)
  4. Version of Record published: August 30, 2016 (version 2)

Copyright

© 2016, Vogan et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

Metrics

  • 2,414
    Page views
  • 559
    Downloads
  • 40
    Citations

Article citation count generated by polling the highest count across the following sources: Crossref, Scopus, PubMed Central.

Download links

A two-part list of links to download the article, or parts of the article, in various formats.

Downloads (link to download the article as PDF)

Open citations (links to open the citations from this article in various online reference manager services)

Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)

  1. Jacob M Vogan
  2. Xiaozhu Zhang
  3. Daniel T Youmans
  4. Samuel G Regalado
  5. Joshua Z Johnson
  6. Dirk Hockemeyer
  7. Kathleen Collins
(2016)
Minimized human telomerase maintains telomeres and resolves endogenous roles of H/ACA proteins, TCAB1, and Cajal bodies
eLife 5:e18221.
https://doi.org/10.7554/eLife.18221

Share this article

https://doi.org/10.7554/eLife.18221

Further reading

    1. Chromosomes and Gene Expression
    2. Genetics and Genomics
    Erandi Velazquez-Miranda, Ming He
    Insight

    Endothelial cell subpopulations are characterized by unique gene expression profiles, epigenetic landscapes and functional properties.

    1. Cell Biology
    2. Chromosomes and Gene Expression
    Monica Salinas-Pena, Elena Rebollo, Albert Jordan
    Research Article

    Histone H1 participates in chromatin condensation and regulates nuclear processes. Human somatic cells may contain up to seven histone H1 variants, although their functional heterogeneity is not fully understood. Here, we have profiled the differential nuclear distribution of the somatic H1 repertoire in human cells through imaging techniques including super-resolution microscopy. H1 variants exhibit characteristic distribution patterns in both interphase and mitosis. H1.2, H1.3, and H1.5 are universally enriched at the nuclear periphery in all cell lines analyzed and co-localize with compacted DNA. H1.0 shows a less pronounced peripheral localization, with apparent variability among different cell lines. On the other hand, H1.4 and H1X are distributed throughout the nucleus, being H1X universally enriched in high-GC regions and abundant in the nucleoli. Interestingly, H1.4 and H1.0 show a more peripheral distribution in cell lines lacking H1.3 and H1.5. The differential distribution patterns of H1 suggest specific functionalities in organizing lamina-associated domains or nucleolar activity, which is further supported by a distinct response of H1X or phosphorylated H1.4 to the inhibition of ribosomal DNA transcription. Moreover, H1 variants depletion affects chromatin structure in a variant-specific manner. Concretely, H1.2 knock-down, either alone or combined, triggers a global chromatin decompaction. Overall, imaging has allowed us to distinguish H1 variants distribution beyond the segregation in two groups denoted by previous ChIP-Seq determinations. Our results support H1 variants heterogeneity and suggest that variant-specific functionality can be shared between different cell types.