Regulation of heterochromatic DNA replication by histone H3 lysine 27 methyltransferases.
Multiple pathways prevent DNA replication from occurring more than once per cell cycle. These pathways block re-replication by strictly controlling the activity of pre-replication complexes, which assemble at specific sites in the genome called origins. Here we show that mutations in the homologous histone 3 lysine 27 (H3K27) monomethyltransferases, ARABIDOPSIS TRITHORAX-RELATED PROTEIN5 (ATXR5) and ATXR6, lead to re-replication of specific genomic locations. Most of these locations correspond to transposons and other repetitive and silent elements of the Arabidopsis genome. These sites also correspond to high levels of H3K27 monomethylation, and mutation of the catalytic SET domain is sufficient to cause the re-replication defect. Mutation of ATXR5 and ATXR6 also causes upregulation of transposon expression and has pleiotropic effects on plant development. These results uncover a novel pathway that prevents over-replication of heterochromatin in Arabidopsis.
Jacob
Yannick
Y
Department of Biology, Indiana University, 915 East Third Street, Bloomington, Indiana 47405, USA.
Stroud
Hume
H
Leblanc
Chantal
C
Feng
Suhua
S
Zhuo
Luting
L
Caro
Elena
E
Hassel
Christiane
C
Gutierrez
Crisanto
C
Michaels
Scott D
SD
Jacobsen
Steven E
SE
D020816:Amino Acid Motifs; D017360:Arabidopsis / Q000166:cytology / Q000201:enzymology / Q000235:genetics; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D020134:Catalytic Domain / Q000235:genetics; D019175:DNA Methylation; D004261:DNA Replication / Q000235:genetics / Q000502:physiology*; D004251:DNA Transposable Elements / Q000235:genetics; D018744:DNA, Plant / Q000032:analysis / Q000096:biosynthesis; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing; D018745:Genome, Plant / Q000235:genetics; D006570:Heterochromatin / Q000235:genetics* / Q000378:metabolism; D011495:Histone-Lysine N-Methyltransferase / Q000378:metabolism*; D006657:Histones / Q000737:chemistry / Q000378:metabolism*; D008239:Lysine / Q000378:metabolism; D008745:Methylation; D008780:Methyltransferases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D050505:Mutant Proteins / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D018741:Replication Origin
D029681:Arabidopsis Proteins; D004251:DNA Transposable Elements; D018744:DNA, Plant; D006570:Heterochromatin; D006657:Histones; D050505:Mutant Proteins; C542364:ATXR5 protein, Arabidopsis; C542365:ATXR6 protein, Arabidopsis; D008780:Methyltransferases; D011495:Histone-Lysine N-Methyltransferase; D008239:Lysine