Telomere length regulates the epigenetic status of mammalian telomeres and subtelomeres - PubMed (original) (raw)

doi: 10.1038/ng1952. Epub 2007 Jan 21.

Affiliations

Telomere length regulates the epigenetic status of mammalian telomeres and subtelomeres

Roberta Benetti et al. Nat Genet. 2007 Feb.

Abstract

Mammalian telomeres have epigenetic marks of constitutive heterochromatin. Here, we study the impact of telomere length on the maintenance of heterochromatin domains at telomeres. Telomerase-deficient Terc(-/-) mice with short telomeres show decreased trimethylation of histone 3 at Lys9 (H3K9) and histone 4 at Lys20 (H4K20) in telomeric and subtelomeric chromatin as well as decreased CBX3 binding accompanied by increased H3 and H4 acetylation at these regions. Subtelomeric DNA methylation is also decreased in conjunction with telomere shortening in Terc(-/-) mice. In contrast, telomere repeat factors 1 and 2 show normal binding to telomeres independent of telomere length. These results indicate that loss of telomeric repeats leads to a change in the architecture of telomeric and subtelomeric chromatin consisting of loss of heterochromatic features leading to a more 'open' chromatin state. These observations highlight the importance of telomere repeats in the establishment of constitutive heterochromatin at mammalian telomeres and subtelomeres and point to histone modifications as important in counting telomere repeats.

PubMed Disclaimer

Similar articles

Cited by

Publication types

MeSH terms

Substances

LinkOut - more resources