MORC family ATPases required for heterochromatin condensation and gene silencing
Program in Gene Function and Expression; Program in Systems Biology; Department of Biochemistry and Molecular Pharmacology
Medical Subject Headings
Adenosine Triphosphatases; Arabidopsis Proteins; Gene Silencing
Genetics and Genomics | Plant Sciences | Systems Biology
Transposable elements (TEs) and DNA repeats are commonly targeted by DNA and histone methylation to achieve epigenetic gene silencing. We isolated mutations in two Arabidopsis genes, AtMORC1 and AtMORC6, which cause derepression of DNA-methylated genes and TEs but no losses of DNA or histone methylation. AtMORC1 and AtMORC6 are members of the conserved Microrchidia (MORC) adenosine triphosphatase (ATPase) family, which are predicted to catalyze alterations in chromosome superstructure. The atmorc1 and atmorc6 mutants show decondensation of pericentromeric heterochromatin, increased interaction of pericentromeric regions with the rest of the genome, and transcriptional defects that are largely restricted to loci residing in pericentromeric regions. Knockdown of the single MORC homolog in Caenorhabditis elegans also impairs transgene silencing. We propose that the MORC ATPases are conserved regulators of gene silencing in eukaryotes.
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Citation: Science. 2012 Jun 15;336(6087):1448-51. Epub 2012 May 3. Link to article on publisher's site