Bhandari Jay, Guillén-Mendoza Cristina, Banks Kathryn, Eliaz Lillian, Southwell Sierra, Eyaa Darriel, Luna Rosa, Aguilera Andrés, Xue Xiaoyu
Department of Chemistry and Biochemistry, Texas State University, San Marcos, Texas, USA.
Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Seville, Spain; Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Seville, Spain.
J Biol Chem. 2024 Dec;300(12):107996. doi: 10.1016/j.jbc.2024.107996. Epub 2024 Nov 13.
Unscheduled R-loops usually cause DNA damage and replication stress, and are therefore a major threat to genome stability. Several RNA processing factors, including the conserved THO complex and its associated RNA and DNA-RNA helicase UAP56, prevent R-loop accumulation in cells. Here, we investigate the function of ALYREF, an RNA export adapter associated with UAP56 and the THO complex, in R-loop regulation. We demonstrate that purified ALYREF promotes UAP56-mediated R-loop dissociation in vitro, and this stimulation is dependent on its interaction with UAP56 and R-loops. Importantly, we show that ALYREF binds DNA-RNA hybrids and R-loops. Consistently, ALYREF depletion causes R-loop accumulation and R-loop-mediated genome instability in cells. We propose that ALYREF, apart from its known role in RNA metabolism and export, is a key cellular R-loop coregulator, which binds R-loops and stimulates UAP56-driven resolution of unscheduled R-loops during transcription.
非程序性R环通常会导致DNA损伤和复制应激，因此对基因组稳定性构成重大威胁。包括保守的THO复合物及其相关的RNA和DNA-RNA解旋酶UAP56在内的几种RNA加工因子可防止细胞中R环的积累。在这里，我们研究了与UAP56和THO复合物相关的RNA输出衔接蛋白ALYREF在R环调控中的功能。我们证明，纯化的ALYREF在体外促进UAP56介导的R环解离，并且这种刺激取决于它与UAP56和R环的相互作用。重要的是，我们表明ALYREF结合DNA-RNA杂交体和R环。一致地，ALYREF的缺失会导致细胞中R环积累和R环介导的基因组不稳定。我们提出，ALYREF除了在RNA代谢和输出中发挥已知作用外，还是一种关键的细胞R环共调节因子，它结合R环并在转录过程中刺激UAP56驱动的非程序性R环的分解。
