STIM1 translocation to the nucleus protects cells from DNA damage

Area of Science:

• Cellular Biology
• Molecular Biology
• Genetics

Background:

• DNA damage poses a significant threat to cell viability and genetic integrity.
• The DNA damage response (DDR) pathway is crucial for repairing genomic DNA.
• The function of STIM1, an endoplasmic reticulum protein, in DNA repair is largely unknown.

Purpose of the Study:

• To investigate the role of STIM1 in DNA damage response and repair.
• To identify novel nuclear functions of STIM1.
• To understand STIM1's involvement in protecting against endogenous DNA damage and replicative stress.

Main Methods:

• Proteomic analysis to study the STIM1 protein interactome.
• Cellular assays to assess DNA damage, replicative stress, and sensitivity to DNA damaging agents.
• Analysis of STIM1 nuclear translocation and chromatin association.
• Western blot analysis to determine FANCD2 protein levels.

Main Results:

• STIM1 interacts with proteins involved in DNA repair pathways.
• STIM1 translocates to the nucleus in response to DNA damage, particularly interstrand crosslinks (ICLs).
• STIM1-deficient cells exhibit increased basal DNA damage, replicative stress, and sensitivity to ICL-inducing agents like mitomycin-C (MMC).
• STIM1 is essential for normalizing nuclear FANCD2 protein levels, a key player in ICL repair.

Conclusions:

• STIM1 possesses a previously unrecognized nuclear function in DNA repair.
• STIM1 plays a critical role in protecting cells from endogenous DNA damage and replicative stress.
• STIM1 is vital for the response to interstrand crosslinks and maintains genomic stability.
• The findings expand the known repertoire of genes involved in DNA repair and highlight STIM1 as a potential therapeutic target.