R-loops, which are hybrid structures consisting of RNA and DNA, typically form during transcription. These structures play crucial roles in single and double-stranded DNA repair, transcription termination, and telomere repair promotion. Dysregulated R-loop has been linked to DNA damage, excessive recombination, transcription elongation irregularities, and genomic instability, ultimately leading to the onset of cancer, autoimmune diseases, and neurodegenerative disorders. To maintain genomic stability, cells have developed diverse strategies aimed at inhibiting the abnormal accumulation of R-loops. Among all the regulatory proteins, RNase H plays a vital role in R-loop resolution. Herein, the current knowledge of R-loops, including techniques for R-loop identification, R-loop functions in cells. Besides, the mechanisms of R-loop resolution, particularly the roles of RNase H1 and RNase H2 in the process and their distinct regulation were also discussed. This research provides a foundation for future studies of R-loops, and could lead to the development of new diagnostic tools and therapeutic strategies.
|