USP11 controls R-loops by regulating senataxin proteostasis.

Area of Science:

• Molecular Biology
• Genomics
• Biochemistry

Background:

• R-loops, DNA:RNA hybrids, are transcription by-products crucial for genomic stability.
• Dysregulation of R-loops is linked to various diseases, necessitating understanding of their regulatory mechanisms.

Purpose of the Study:

• To elucidate the regulatory mechanism of senataxin (SETX), an R-loop-specific helicase.
• To identify novel regulators of R-loop homeostasis and their role in genomic integrity.

Main Methods:

• Investigated the interaction between USP11 and SETX using biochemical assays.
• Utilized cell-based assays, including knockout models and overexpression studies, to assess R-loop levels and DNA damage.
• Analyzed protein ubiquitination and turnover rates via Western blotting and proteasome inhibition.

Main Results:

• Identified USP11 as a de-ubiquitinase for SETX, controlling its stability and turnover.
• Loss of USP11 leads to increased SETX ubiquitination, reduced SETX levels, and impaired R-loop dissolution.
• USP11 deficiency results in R-loop accumulation, XPF enrichment, and double-strand breaks, particularly at the KEAP1 promoter.

Conclusions:

• Established a ubiquitination-dependent regulatory pathway for SETX involving USP11 and KEAP1.
• Demonstrated that USP11-mediated regulation of SETX is critical for preventing R-loop accumulation and maintaining genomic stability.
• Highlighted the potential therapeutic implications of targeting this pathway in cancer and neurological disorders.