ER stress tolerance is regulated by copper-dependent PERK kinase activity

Area of Science:

• Biochemistry
• Cellular Biology
• Molecular Signaling

Background:

• Endoplasmic reticulum (ER) stress triggers signaling pathways, including PERK, which balances cell survival and death.
• The precise regulation of PERK activity and its role in adaptive versus maladaptive signaling remain unclear.
• Understanding PERK regulation is crucial for addressing cellular stress responses.

Purpose of the Study:

• To investigate the molecular mechanisms regulating Pancreatic/PKR-like endoplasmic reticulum kinase (PERK) activity.
• To determine the role of metal ions, specifically copper, in PERK function.
• To explore the therapeutic potential of targeting the copper-PERK interaction.

Main Methods:

• Purification of PERK protein for in vitro biochemical assays.
• Identification of copper-binding residues within PERK.
• Cellular assays to assess PERK activity under varying copper availability.
• In vivo studies using a C. elegans model to evaluate ER stress sensitivity.

Main Results:

• Demonstrated direct binding of purified PERK to copper.
• Identified specific amino acid residues critical for copper interaction.
• Showed that copper is essential for PERK kinase activity.
• Established that cellular PERK activity and ER stress tolerance are modulated by copper availability.
• Observed exacerbated ER-stress sensitivity in a C. elegans PERK-copper mutant.

Conclusions:

• Copper is a novel and essential regulator of PERK kinase activity.
• The copper-PERK interaction provides a new paradigm for understanding ER stress signaling.
• Copper homeostasis represents a potential therapeutic target for modulating PERK-mediated diseases.