RT Journal Article SR Electronic T1 ALBA protein complex reads genic R-loops to maintain genome stability in Arabidopsis JF Science Advances JO Sci Adv FD American Association for the Advancement of Science SP eaav9040 DO 10.1126/sciadv.aav9040 VO 5 IS 5 A1 Yuan, Wei A1 Zhou, Jincong A1 Tong, Jinjin A1 Zhuo, Wanqing A1 Wang, Lishuan A1 Li, Yan A1 Sun, Qianwen A1 Qian, Weiqiang YR 2019 UL http://advances.sciencemag.org/content/5/5/eaav9040.abstract AB The R-loop, composed of a DNA-RNA hybrid and the displaced single-stranded DNA, regulates diverse cellular processes. However, how cellular R-loops are recognized remains poorly understood. Here, we report the discovery of the evolutionally conserved ALBA proteins (AtALBA1 and AtALBA2) functioning as the genic R-loop readers in Arabidopsis. While AtALBA1 binds to the DNA-RNA hybrid, AtALBA2 associates with single-stranded DNA in the R-loops in vitro. In vivo, these two proteins interact and colocalize in the nucleus, where they preferentially bind to genic regions with active epigenetic marks in an R-loop–dependent manner. Depletion of AtALBA1 or AtALBA2 results in hypersensitivity of plants to DNA damaging agents. The formation of DNA breaks in alba mutants originates from unprotected R-loops. Our results reveal that the AtALBA1 and AtALBA2 protein complex is the genic R-loop reader crucial for genome stability in Arabidopsis.