ZC3H4 safeguards genome integrity by preventing transcription-replication conflicts at noncoding RNA loci

Area of Science:

• Molecular Biology
• Genetics
• Cell Biology

Background:

• Genome stability is maintained by cellular networks regulating nucleic acid metabolism.
• Noncoding RNAs (ncRNAs) play roles in genome regulation.
• Replication stress (RS) is a significant contributor to genome instability.

Purpose of the Study:

• To identify key regulators of genome stability.
• To investigate the role of Zinc Finger CCCH-Type Containing 4 (ZC3H4) protein in maintaining genome integrity.
• To elucidate the molecular mechanisms by which ZC3H4 influences replication stress.

Main Methods:

• Bioinformatic analysis to identify ZC3H4.
• Experimental studies involving ZC3H4-deficient cells.
• Biochemical assays and super-resolution microscopy.
• Analysis of DNA damage, mitosis, and cellular senescence.
• Assessment of R loop formation and transcription-replication conflicts (TRCs).

Main Results:

• ZC3H4 deficiency leads to increased DNA damage, abnormal mitosis, and cellular senescence.
• Loss of ZC3H4 induces a hypertranscription state, promoting R loop formation and TRCs, thereby increasing replication stress.
• ZC3H4 binds to genomic regions susceptible to TRCs and R loops.
• ZC3H4 functions within the Restrictor complex to suppress ncRNA bursts.

Conclusions:

• ZC3H4 is a critical suppressor of ncRNA production and a key factor in maintaining genome integrity.
• ZC3H4 acts at the interface of DNA and RNA synthesis to prevent replication stress.
• Targeting ZC3H4 function may offer strategies for managing genome instability-related diseases.