On the mechanism of induction of heterochromatin by the RNA-binding protein vigilin

Jing Zhou; Qiaoqiao Wang; Ling-Ling Chen; Gordon G. Carmichael

doi:10.1261/rna.1036308

On the mechanism of induction of heterochromatin by the RNA-binding protein vigilin

Department of Genetics and Developmental Biology, University of Connecticut Stem Cell Institute, University of Connecticut Health Center, Farmington, Connecticut 06030-3301, USA

Abstract

Vigilin is an RNA-binding protein localized to both the cytoplasm and the nucleus and has been previously implicated in heterochromatin formation and chromosome segregation. We demonstrate here that the C-terminal domain of human vigilin binds to the histone methyltransferase SUV39H1 in vivo. This association is independent of RNA and maps to a site on vigilin that is not involved in its interaction with several other known protein partners. Cells that express high levels of the C-terminal fragment display chromosome segregation defects, and ChIP analyses show changes in the status of pericentric β-satellite and rDNA chromatin from heterochromatic to more euchromatic form. Finally, a cell line with inducible expression of the vigilin C-terminal fragment displays inducible alterations in β-satellite chromatin. These and other results lead us to present a new model for vigilin-mediated, RNA-induced gene silencing.

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Footnotes

↵1 Present address: Yale Stem Cell Center and Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06509, USA.
Reprint requests to: Gordon G. Carmichael, Department of Genetics and Developmental Biology, University of Connecticut Stem Cell Institute, University of Connecticut Health Center, Farmington, CT 06030-3301, USA; e-mail: carmichael{at}nso2.uchc.edu; fax: (860) 679-8345.
Article published online ahead of print. Article and publication date are at http://www.rnajournal.org/cgi/doi/10.1261/rna.1036308.
- Received February 20, 2008.
- Accepted May 22, 2008.