IDN2 Interacts with RPA and Facilitates DNA Double-Strand Break Repair by Homologous Recombination in Arabidopsis

Abstract

<p class="first" id="d14771717e296">IDN2, a dsRNA binding protein, interacts with replication protein A and facilitates its release from ssDNA tails and the subsequent recruitment of RAD51 at DSB sites, promoting homologous recombination repair. </p><p class="first" id="d14771717e299">Repair of DNA double-strand breaks (DSBs) is critical for the maintenance of genome integrity. We previously showed that <a class="xref-link" href="#def1">DSB</a>-induced small RNAs (diRNAs) facilitate homologous recombination-mediated <a class="xref-link" href="#def1">DSB</a> repair in <i>Arabidopsis thaliana</i>. Here, we show that INVOLVED IN DE NOVO2 (IDN2), a double-stranded RNA binding protein involved in small RNA-directed DNA methylation, is required for <a class="xref-link" href="#def1">DSB</a> repair in Arabidopsis. We find that IDN2 interacts with the heterotrimeric replication protein A (RPA) complex. Depletion of IDN2 or the <a class="xref-link" href="#def6">diRNA</a> binding ARGONAUTE2 leads to increased accumulation of RPA at <a class="xref-link" href="#def1">DSB</a> sites and mislocalization of the recombination factor RAD51. These findings support a model in which IDN2 interacts with RPA and facilitates the release of RPA from single-stranded DNA tails and subsequent recruitment of RAD51 at <a class="xref-link" href="#def1">DSB</a> sites to promote <a class="xref-link" href="#def1">DSB</a> repair. </p>