Format

Send to

Choose Destination
Nature. 2008 Jan 24;451(7177):431-6. Epub 2007 Dec 19.

Host genome surveillance for retrotransposons by transposon-derived proteins.

Author information

1
Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, Bethesda, Maryland 20892, USA.

Abstract

Transposable elements and their remnants constitute a substantial fraction of eukaryotic genomes. Host genomes have evolved defence mechanisms, including chromatin modifications and RNA interference, to regulate transposable elements. Here we describe a genome surveillance mechanism for retrotransposons by transposase-derived centromeric protein CENP-B homologues of the fission yeast Schizosaccharomyces pombe. CENP-B homologues of S. pombe localize at and recruit histone deacetylases to silence Tf2 retrotransposons. CENP-Bs also repress solo long terminal repeats (LTRs) and LTR-associated genes. Tf2 elements are clustered into 'Tf' bodies, the organization of which depends on CENP-Bs that display discrete nuclear structures. Furthermore, CENP-Bs prevent an 'extinct' Tf1 retrotransposon from re-entering the host genome by blocking its recombination with extant Tf2, and silence and immobilize a Tf1 integrant that becomes sequestered into Tf bodies. Our results reveal a probable ancient retrotransposon surveillance pathway important for host genome integrity, and highlight potential conflicts between DNA transposons and retrotransposons, major transposable elements believed to have greatly moulded the evolution of genomes.

Comment in

PMID:
18094683
DOI:
10.1038/nature06499
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Nature Publishing Group
Loading ...
Support Center