PERK orchestrates an endoplasmic reticulum stress alternative splicing program via CLK1/SRSF1

Area of Science:

• Cellular Biology
• Molecular Biology
• Genetics

Background:

• The unfolded protein response (UPR) is a cellular stress response that alters protein synthesis.
• Investigating rapid translatome changes during stress is challenging.
• Understanding stress-induced rewiring of gene expression is crucial.

Purpose of the Study:

• To investigate de novo protein synthesis during endoplasmic reticulum (ER) stress.
• To identify mechanisms of translatome rewiring upon ER stress.
• To characterize the impact of ER stress on RNA splicing.

Main Methods:

• O-Propargyl-puromycin (OPP) labeling of newly synthesized peptides.
• Liquid chromatography-tandem mass spectrometry (LC-MS/MS) for proteomic analysis.
• Transcriptomic analysis, pharmacological, genetic, and phosphoproteomic approaches.

Main Results:

• ER stress significantly impacts the synthesis of core splicing factor proteins.
• A distinct signature of seven splicing events was identified during ER stress.
• This splicing signature is driven by PERK activation and the CLK1/SRSF1 axis.

Conclusions:

• ER stress profoundly reshapes the splicing landscape through PERK/CLK1/SRSF1-mediated regulation.
• This defines a novel ER stress-induced splicing signature (ERi-splice).
• The ERi-splice signature is conserved in healthy and malignant tissues.