title: An Arabidopsis SET domain protein required for maintenance but not establishment of DNA methylation.
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.
authors.affiliation: Department of Biochemistry and Molecular Biology, Johns Hopkins University Bloomberg School of Public Health, 615 N. Wolfe Street, Baltimore, MD 21205, USA.
authors.forename: Fabienne
authors.initials: F
authors.lastname: Malagnac
authors.forename: Lisa
authors.initials: L
authors.lastname: Bartee
authors.forename: Judith
authors.initials: J
authors.lastname: Bender
mesh_terms: D019747:Aldose-Ketose Isomerases / Q000378:metabolism*; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000737:chemistry* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D003001:Cloning, Molecular; D003596:Cytosine / Q000378:metabolism; D019175:DNA Methylation; D004252:DNA Mutational Analysis; D015257:DNA-Cytosine Methylases / Q000235:genetics; D020868:Gene Silencing; D011495:Histone-Lysine N-Methyltransferase / Q000378:metabolism*; D006657:Histones / Q000378:metabolism*; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D013447:Sulfites / Q000494:pharmacology; D019076:Transgenes
chemical_list: D029681:Arabidopsis Proteins; D006657:Histones; D013447:Sulfites; D003596:Cytosine; D015257:DNA-Cytosine Methylases; C429766:CMT3 protein, Arabidopsis; D011495:Histone-Lysine N-Methyltransferase; C471228:SUVH4 protein, Arabidopsis; D019747:Aldose-Ketose Isomerases; C471229:PAI2 protein, Arabidopsis