Description

Telomerase is a ribonucleoprotein (RNP) enzyme that requires an integral telomerase RNA (TR) subunit, in addition to the catalytic telomerase reverse transcriptase (TERT), for enzymatic function. The secondary structures of TRs from the three major groups of species, ciliates, fungi,

Telomerase is a ribonucleoprotein (RNP) enzyme that requires an integral telomerase RNA (TR) subunit, in addition to the catalytic telomerase reverse transcriptase (TERT), for enzymatic function. The secondary structures of TRs from the three major groups of species, ciliates, fungi, and vertebrates, have been studied extensively and demonstrate dramatic diversity. Herein, we report the first comprehensive secondary structure of TR from echinoderms—marine invertebrates closely related to vertebrates—determined by phylogenetic comparative analysis of 16 TR sequences from three separate echinoderm classes. Similar to vertebrate TR, echinoderm TR contains the highly conserved template/pseudoknot and H/ACA domains. However, echinoderm TR lacks the ancestral CR4/5 structural domain found throughout vertebrate and fungal TRs. Instead, echinoderm TR contains a distinct simple helical region, termed eCR4/5, that is functionally equivalent to the CR4/5 domain. The urchin and brittle star eCR4/5 domains bind specifically to their respective TERT proteins and stimulate telomerase activity. Distinct from vertebrate telomerase, the echinoderm TR template/pseudoknot domain with the TERT protein is sufficient to reconstitute significant telomerase activity. This gain-of-function of the echinoderm template/pseudoknot domain for conferring telomerase activity presumably facilitated the rapid structural evolution of the eCR4/5 domain throughout the echinoderm lineage. Additionally, echinoderm TR utilizes the template-adjacent P1.1 helix as a physical template boundary element to prevent nontelomeric DNA synthesis, a mechanism used by ciliate and fungal TRs. Thus, the chimeric and eccentric structural features of echinoderm TR provide unparalleled insights into the rapid evolution of telomerase RNP structure and function.

Reuse Permissions
  • Downloads
    PDF (472.7 KB)

    Details

    Title
    • Structure and Function of Echinoderm Telomerase RNA
    Contributors
    Date Created
    2015-11-23
    Resource Type
  • Text
  • Collections this item is in
    Identifier
    • Digital object identifier: 10.1261/rna.053280.115
    • Identifier Type
      International standard serial number
      Identifier Value
      1355-8382
    • Identifier Type
      International standard serial number
      Identifier Value
      1469-9001
    Note
    • The final version of this article, as published in RNA, can be viewed online at: http://rnajournal.cshlp.org/content/22/2/204

    Citation and reuse

    Cite this item

    This is a suggested citation. Consult the appropriate style guide for specific citation guidelines.

    Podlevsky, J. D., Li, Y., & Chen, J. J. (2015). Structure and function of echinoderm telomerase RNA. Rna, 22(2), 204-215. doi:10.1261/rna.053280.115

    Machine-readable links