Transcription shapes DNA replication initiation and termination in human cells

Area of Science:

• Molecular Biology
• Genomics
• Cell Biology

Background:

• DNA replication is essential for cell division but its regulation in the human genome remains unclear.
• Understanding replication start and stop sites is crucial for genome stability.

Purpose of the Study:

• To directly identify and compare replication initiation and termination sites in human cells.
• To investigate the relationship between DNA replication and gene transcription.
• To explore how replication dynamics change under replication stress.

Main Methods:

• Direct identification and quantitative comparison of replication origins and termination zones.
• Analysis in untransformed human cells.
• Assessment of replication patterns during replication stress.

Main Results:

• Replication preferentially initiates at transcription start sites of highly transcribed genes (occupied by RNA polymerase II).
• Replication terminates at polyadenylation sites, ensuring co-directionality with transcription, particularly at gene 5' ends.
• Replication stress alters initiation and termination sites, reorienting replication relative to transcription around gene 3' ends.

Conclusions:

• Replication initiation and termination are coupled to transcription in human cells.
• A model is proposed for how replication stress impacts genome integrity through altered replication-transcription dynamics.