Double stranded DNA breaks and genome editing trigger loss of ribosomal protein RPS27A

Area of Science:

• Molecular Biology
• Cellular Biology
• Genomics

Background:

• DNA damage elicits transcriptional stress responses, but its impact on translation remains less understood.
• Genome editing technologies like Cas9 have increased the need to study cellular responses to DNA damage.
• Understanding how DNA damage affects protein synthesis is crucial for interpreting cellular behavior.

Purpose of the Study:

• To investigate the effects of DNA double-strand breaks (DSBs) on cellular translation.
• To determine if Cas9-induced DNA damage impacts protein synthesis and ribosome composition.
• To elucidate the relationship between DNA damage, translation, and transcript abundance.

Main Methods:

• Induction of DNA double-strand breaks (DSBs) using Cas9.
• Ribosome profiling and mRNA sequencing (mRNA-seq) to compare Cas9 and dCas9 treated cells.
• Analysis of ribosomal protein loss and proteasomal degradation pathways.

Main Results:

• DNA double-strand breaks (DSBs) induce the loss of ribosomal protein RPS27A from ribosomes.
• This loss occurs via p53-independent proteasomal degradation.
• A global translational response to DSBs was observed, preceding alterations in mRNA levels.
• Even a single DSB can remodel ribosomes and change translational output.

Conclusions:

• DNA damage significantly impacts cellular translation by altering ribosome composition.
• Cas9-mediated genome editing can induce translational changes that precede transcriptional alterations.
• Caution is advised when interpreting cellular phenotypes immediately following genome editing due to rapid translational remodeling.