VID22 counteracts G-quadruplex-induced genome instability.

Area of Science:

• Molecular Biology
• Genetics
• Biochemistry

Background:

• Genome instability is a key characteristic of cancer cells, involving accumulated genetic alterations.
• Understanding endogenous DNA damage and genome integrity pathways is crucial for cancer research.

Purpose of the Study:

• To identify novel genes and cellular pathways involved in maintaining genome integrity.
• To investigate the function of the VID22 gene in DNA repair and genome stability.

Main Methods:

• Utilized a Synthetic Genetic Array (SGA)-based screen in yeast to identify genes affecting genome integrity.
• Performed in vitro and in vivo experiments to assess Vid22's DNA binding and protective capabilities.
• Analyzed DNA aberrations, chromosomal rearrangements, and telomere/mtDNA maintenance in vid22Δ cells.

Main Results:

• Identified VID22 as a gene involved in DNA double-strand break repair and genome integrity.
• vid22Δ cells show increased endogenous DNA damage, chronic DNA damage response, and DNA aberrations, particularly in G-quadruplex (G4-DNA) forming regions.
• Vid22 binds to and protects DNA at G4 regions, and its absence increases G-quadruplex-dependent chromosomal rearrangements.
• Loss of VID22 impairs maintenance of G4-DNA rich elements like telomeres and mtDNA, causing hypersensitivity to G4 ligands.

Conclusions:

• Vid22 directly contributes to genome integrity maintenance.
• Vid22 acts as a novel regulator of G-quadruplex (G4-DNA) metabolism, protecting against DNA damage and aberrations.
• The findings suggest Vid22's critical role in preventing genome instability and potentially cancer development.