Poster abstracts
Poster number 120 submitted by Hafiz Rothi
Noncoding RNA-mediated DNA methylation controls nucleosome positioning
M Hafiz Rothi (Department of Molecular, Cellular, and Developmental Biology, University of Michigan), Shriya Sethuraman (Department of Computational Medicine and Bioinformatics, University of Michigan), Jakub Dolata (Department of Gene Expression, Adam Mickiewicz University Poznan), Andrzej T Wierzbicki (Department of Molecular, Cellular, and Developmental Biology, University of Michigan)
Abstract:
In Arabidopsis thaliana, noncoding RNAs (ncRNAs) are produced in the RNA-directed DNA methylation (RdDM) pathway to target transposable elements for silencing. Previously, we had identified the SWI/SNF chromatin remodeling complex to possibly function downstream of RNA Polymerase V (Pol V) transcription. Here, we show that Pol V positions nucleosomes through the SWI/SNF chromatin remodeling complex. The positioned nucleosomes are enriched with DNA methylation and histone 3 lysine 9 di-methylation (H3K9me2). IDN2, an RNA-binding protein functioning downstream of Pol V, connects short interfering RNA (siRNA) and long noncoding (lncRNA) to nucleosome positioning. We established that DNA methylation is preferentially enriched in linker regions genome-wide and that SWI/SNF is not required for DNA methylation in Pol V positioned nucleosomes. However, in DNA methyltransferase mutants, we observed a loss of nucleosome signal in differentially methylated regions. We propose a model where RdDM pathway directs nucleosome positioning through DNA methylation.
Keywords: noncoding RNA, chromatin, gene regulation