DNA damage-induced phosphorylation of the human telomere-associated protein TRF2

Hiromi Tanaka, Marc S. Mendonca, Paul S. Bradshaw, Derek J. Hoelz, Linda H. Malkas, M. Stephen Meyn, David Gilley

Research output: Contribution to journalArticle

74 Scopus citations


Several protein kinases from diverse eukaryotes known to perform important roles in DNA repair have also been shown to play critical roles in telomere maintenance. Here, we report that the human telomere-associated protein TRF2 is rapidly phosphorylated in response to DNA damage. We find that the phosphorylated form of TRF2 is not bound to telomeric DNA, as is the ground form of TRF2, and is rapidly localized to damage sites. Our results suggest that the ataxia-telangiectasia-mutated (ATM) protein kinase signal-transduction pathway is primarily responsible for the DNA damage-induced phosphorylation of TRF2. Unlike DMA damage-induced phosphorylation of other ATM targets, the phosphorylated form of TRF2 is transient, being detected rapidly at DNA damage sites postirradiation, but largely dissipated by 2 hours. In addition, we report that the phosphorylated form of TRF2 is present at telomeres in cell types undergoing telomere-based crisis and a recombination-driven, telomerase-independent, alternative lengthening of telomeres (ALT) pathway, likely as a consequence of a telomere-based DNA damage response. Our results link the induction of TRF2 phosphorylation to the DNA damage-response system, providing an example of direct cross-talk via a signaling pathway between these two major cellular processes essential for genomic stability, telomere maintenance, and DNA repair.

Original languageEnglish (US)
Pages (from-to)15539-15544
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number43
StatePublished - Oct 25 2005


ASJC Scopus subject areas

  • General

Cite this