NKAP acts with HDAC3 to prevent R-loop associated genome instability

Area of Science:

• Molecular Biology
• Genetics
• Cell Biology

Background:

• Persistent R-loop accumulation is linked to DNA damage, genome instability, and human diseases.
• Understanding R-loop homeostasis regulators is crucial for cellular physiology and pathology.

Purpose of the Study:

• To identify molecules and pathways controlling R-loop homeostasis.
• To investigate the role of NF-κB activating protein (NKAP) in preventing R-loop accumulation and maintaining genome integrity.

Main Methods:

• Protein complex formation analysis (NKAP-HDAC3).
• Depletion studies (NKAP, HDAC3) to assess DNA damage and R-loop levels.
• Analysis of transcription-dependent R-loop induction.
• Assessment of RNA polymerase II pausing.
• Investigation of DNA double-strand break formation by endonucleases (XPF, XPG).

Main Results:

• NKAP depletion leads to R-loop accumulation, DNA damage, and genome instability.
• HDAC3 stabilizes NKAP and also suppresses R-loop associated DNA damage.
• NKAP maintains genome integrity by promoting RNA polymerase II pausing.
• R-loops induced by NKAP or HDAC3 depletion are processed into DNA double-strand breaks by XPF/XPG.

Conclusions:

• NKAP and HDAC3 are novel key regulators of R-loop homeostasis.
• Dysregulation of NKAP and HDAC3 can lead to R-loop associated genome instability and may drive tumorigenesis.