Nascent RNA at the crossroad of transcription and replication.

Abstract

The concurrent processes of DNA replication and RNA transcription pose a significant challenge to genome integrity. Nascent RNA, the newly synthesized transcript, is emerging as a critical determinant of transcription-replication conflict (TRC) outcomes, exerting influence through its modifications, its ability to form RNA:DNA hybrids (R-loops), its regulation of chromatin structure, and its interaction with protein complexes at the transcription-replication interface. Here, we synthesize recent advances on how nascent RNA modulates transcription dynamics, replication fork progression, and genome stability. We explore its paradoxical roles - both inducing replication stress and orchestrating protective responses - highlighting how RNA processing factors mitigate TRCs. Finally, we emphasize the need for innovative technologies to dissect the dynamic and context-dependent roles of nascent RNA and therapeutic potential for genomic instability-linked diseases.