Work

High-frequency transcription leads to rapid R-loop formation

Year: 2025

Type: article

Abstract: R-loops are transcriptionally generated three-stranded nucleic acid structures where the mRNA hybridizes with template DNA, leaving a displaced single-stranded non-template DNA loop. Previously, we demonstrated that R-loop and subsequent G-quadruplex formation upregulate transcription. However, the mechanistic basis of how transcription activity generates R-loop formation is unknown. Here, we investigate the kinetics of transcription and its impact on R-loop formation using single-molecule FRET and EMSA. We show that R-loop formation is tuned by the frequency and the rate of transcription, controlled by the RNA polymerase and NTP concentrations, respectively. We provide a plausible mechanism in which gradually increasing the duration of the promoter opening leads to the R-loop formation. Through stochastic simulation, we demonstrate that the frequency of transcription primarily governs R-loop formation. This work highlights the intricate balance between transcription dynamics and R-loop formation, providing new insights into the structure-function relationship.

Source: Journal of Biological Chemistry

DOI: 10.1016/j.jbc.2025.108514

Authors: Bradleigh Palmer, Chun-Ying Lee, Leya Yang, Tapas Paul, Sua Myong

Institutions: Johns Hopkins University, Boston Children's Hospital

Language: English

Topic: DNA and Nucleic Acid Chemistry

Subfield: Molecular Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: gold

Estimated APC paid: $3,430

Funders: National Institutes of Health, National Institute of General Medical Sciences