Multimegabase Silencing in Nucleolar Dominance Involves siRNA-Directed DNA Methylation and Specific Methylcytosine-Binding Proteins

被引：114

作者：

Preuss, Sasha B. ^{[1
]}

Costa-Nunes, Pedro ^{[1
,6
]}

Tucker, Sarah ^{[1
]}

Pontes, Olga ^{[1
]}

Lawrence, Richard J. ^{[1
]}

Mosher, Rebecca ^{[2
,3
]}

Kasschau, Kristin D. ^{[4
,5
]}

Carrington, James C. ^{[4
,5
]}

Baulcombe, David C. ^{[2
,3
]}

Viegas, Wanda ^{[6
]}

Pikaard, Craig S. ^{[1
]}

机构：

[1] Washington Univ, Dept Biol, St Louis, MO 63130 USA

[2] Univ Cambridge, Dept Plant Sci, Cambridge CB2 3EA, England

[3] John Innes Inst, Sainsbury Lab, Norwich NR4 7UH, Norfolk, England

[4] Oregon State Univ, Ctr Genome Res & Biocomp, Corvallis, OR 97331 USA

[5] Oregon State Univ, Dept Bot & Plant Pathol, Corvallis, OR 97331 USA

[6] Univ Tecn Lisboa, Inst Super Agron, Ctr Bot Aplicada & Agr, P-1349017 Lisbon, Portugal

来源：

MOLECULAR CELL | 2008年 / 32卷 / 05期

基金：

美国国家科学基金会;

关键词：

D O I：

10.1016/j.molcel.2008.11.009

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

In genetic hybrids, the silencing of nucleolar rRNA genes inherited from one progenitor is the epigenetic phenomenon known as nucleolar dominance. An RNAi knockdown screen identified the Arabidopsis de novo cytosine methyltransferase, DRM2, and the methylcytosine binding domain proteins, MBD6 and MBD10, as activities required for nucleolar dominance. MBD10 localizes throughout the nucleus, but MBD6 preferentially associates with silenced rRNA genes and does so in a DRM2-dependent manner. DRM2 methylation is thought to be guided by siRNAs whose biogenesis requires RNA-DEPENDENT RNA POLYMERASE 2 (RDR2) and DICER-LIKE 3 (DCL3). Consistent with this hypothesis, knockdown of DCL3 or RDR2 disrupts nucleolar dominance. Collectively, these results indicate that in addition to directing the silencing of retrotransposons and noncoding repeats, siRNAs specify de novo cytosine methylation patterns that are recognized by MBD6 and MBD10 in the large-scale silencing of rRNA gene loci.

引用

页码：673 / 684

页数：12

共 56 条

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