DDX54 regulates transcriptome dynamics during DNA damage response

Area of Science:

• Molecular Biology
• Cellular Biology
• Genetics

Background:

• The DNA damage response (DDR) is critical for maintaining genomic stability.
• Post-transcriptional gene regulation's role in the DDR is not well understood.
• RNA-binding proteins (RBPs) are key regulators of gene expression.

Purpose of the Study:

• To identify RBPs that interact with polyadenylated transcripts upon genotoxic stress.
• To investigate the function of the RNA helicase DDX54 in the DDR.
• To understand how DDX54 influences pre-mRNA splicing during DNA damage.

Main Methods:

• Systematic identification of RBPs binding to poly(A)+ RNA in human breast carcinoma cells exposed to ionizing radiation (IR).
• Functional analysis of DDX54, including its interactions and role in splicing.
• Assessment of DDX54's impact on cell survival after IR exposure.

Main Results:

• Over 260 proteins, including nucleolar proteins, increased their binding to poly(A)+ RNA after IR.
• DDX54 was identified as an immediate-to-early DDR regulator.
• DDX54 enhances splicing of IR-induced pre-mRNAs with weak acceptor splice sites, reducing intron retention and increasing processing rates.
• DDX54 promotes cell survival following IR exposure.

Conclusions:

• RBPs, particularly DDX54, are significant regulators of the DDR.
• DDX54's function in splicing is essential for efficient DNA damage repair and cell survival.
• Uncharacterized RBPs may represent novel targets for understanding and treating DDR-related pathologies.