Send to

Choose Destination
EMBO J. 2009 Nov 18;28(22):3549-63. doi: 10.1038/emboj.2009.278. Epub 2009 Sep 24.

The MRT-1 nuclease is required for DNA crosslink repair and telomerase activity in vivo in Caenorhabditis elegans.

Author information

Department of Genetics, University of North Carolina, Chapel Hill, NC, USA.


The telomerase reverse transcriptase adds de novo DNA repeats to chromosome termini. Here we define Caenorhabditis elegans MRT-1 as a novel factor required for telomerase-mediated telomere replication and the DNA-damage response. MRT-1 is composed of an N-terminal domain homologous to the second OB-fold of POT1 telomere-binding proteins and a C-terminal SNM1 family nuclease domain, which confer single-strand DNA-binding and processive 3'-to-5' exonuclease activity, respectively. Furthermore, telomerase activity in vivo depends on a functional MRT-1 OB-fold. We show that MRT-1 acts in the same telomere replication pathway as telomerase and the 9-1-1 DNA-damage response complex. MRT-1 is dispensable for DNA double-strand break repair, but functions with the 9-1-1 complex to promote DNA interstrand cross-link (ICL) repair. Our data reveal MRT-1 as a dual-domain protein required for telomerase function and ICL repair, which raises the possibility that telomeres and ICL lesions may share a common feature that plays a critical role in de novo telomere repeat addition.

[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Wiley Icon for PubMed Central
Loading ...
Support Center