Send to

Choose Destination
Curr Biol. 2006 Jul 11;16(13):1295-302. Epub 2006 May 25.

Apollo, an Artemis-related nuclease, interacts with TRF2 and protects human telomeres in S phase.

Author information

Laboratory for Cell Biology and Genetics, The Rockefeller University, 1230 York Avenue, New York, New York 10021, USA.


Human chromosome ends are protected by shelterin, an abundant six-subunit protein complex that binds specifically to the telomeric-repeat sequences, regulates telomere length, and ensures that chromosome ends do not elicit a DNA-damage response (reviewed in). Using mass spectrometry of proteins associated with the shelterin component Rap1, we identified an SMN1/PSO2 nuclease family member that is closely related to Artemis. We refer to this protein as Apollo and report that Apollo has the ability to localize to telomeres through an interaction with the shelterin component TRF2. Although its low abundance at telomeres indicates that Apollo is not a core component of shelterin, Apollo knockdown with RNAi resulted in senescence and the activation of a DNA-damage signal at telomeres as evidenced by telomere-dysfunction-induced foci (TIFs). The TIFs occurred primarily in S phase, suggesting that Apollo contributes to a processing step associated with the replication of chromosome ends. Furthermore, some of the metaphase chromosomes showed two telomeric signals at single-chromatid ends, suggesting an aberrant telomere structure. We propose that the Artemis-like nuclease Apollo is a shelterin accessory factor required for the protection of telomeres during or after their replication.

Comment in

[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center