Article
- The EMBO Journal (2002) 21, 6842 - 6852
- doi:10.1093/emboj/cdf687
Subject Categories:
An Arabidopsis SET domain protein required for maintenance but not establishment of DNA methylation
Fabienne Malagnac2, Lisa Bartee1 and Judith Bender1
- Department of Biochemistry and Molecular Biology, Johns Hopkins University Bloomberg School of Public Health, 615 N. Wolfe Street, Baltimore, MD 21205, USA
- Present address: Institut de Gnétiqué et Microbiologie, CNRS/Université Paris-Sud, Bâtiment 400, 91405 Orsay Cedex, France
Correspondence to:
Judith Bender, E-mail: jbender@mail.jhmi.edu
Received 28 August 2002; Accepted 30 October 2002; Revised 21 October 2002
Abstract
Cytosine methylation is critical for correct development and genome stability in mammals and plants. In order to elucidate the factors that control genomic DNA methylation patterning, a genetic screen for mutations that disrupt methylation-correlated silencing of the endogenous gene PAI2 was conducted in Arabidopsis. This screen yielded seven loss-of-function alleles in a SET domain protein with histone H3 Lys9 methyltransferase activity, SUVH4. The mutations conferred reduced cytosine methylation on PAI2, especially in non-CG sequence contexts, but did not affect methylation on another PAI locus carrying two genes arranged as an inverted repeat. Moreover, an unmethylated PAI2 gene could be methylated de novo in the suvh4 mutant background. These results suggest that SUVH4 is involved in maintenance but not establishment of methylation at particular genomic regions. In contrast, a heterochromatin protein 1 homolog, LHP1, had no effect on PAI methylation.
Keywords:
- DNA methylation,
- epigenetics,
- gene silencing,
- histone methylation
