Transcriptional elongation requires DNA break-induced signalling

Area of Science:

• Molecular Biology
• Gene Regulation
• DNA Damage Response

Background:

• RNA polymerase II (Pol II) transcription requires precise regulation of pause release and elongation.
• The DNA damage response (DDR) pathway, involving kinases like ATM and DNA-PK, has been implicated in Pol II function.
• The specific role of DDR signaling in transcriptional elongation of inducible genes remains to be fully elucidated.

Purpose of the Study:

• To investigate the role of DNA breaks and DDR signaling in transcriptional elongation of stimulus-inducible genes in humans.
• To identify key factors and mechanisms involved in this process.

Main Methods:

• Analysis of TRIM28 and γH2AX enrichment on serum-induced genes.
• Inhibition studies using P-TEFb and topoisomerase II inhibitors.
• Assessment of Pol II pause release and DDR signaling activation.

Main Results:

• TRIM28 and γH2AX are enriched on human serum-induced genes.
• DNA-PK is essential for Pol II pause release and activation-coupled DDR signaling.
• DDR signaling is a consequence of transcriptional elongation, as indicated by P-TEFb inhibition studies.
• Topoisomerase II is involved in transcriptional elongation-coupled DDR signaling.

Conclusions:

• DDR signaling plays a significant role in transcriptional elongation of stimulus-inducible genes.
• A novel mechanism involving TRIM28, DNA-PK, and topoisomerase II facilitates Pol II pause release and elongation.