Stress Granule Dysfunction via Chromophore-Associated Light Inactivation.

Area of Science:

• Cell Biology
• Biochemistry
• Molecular Biology

Background:

• Stress granules (SGs) are dynamic cytoplasmic condensates crucial for cellular protection during stress.
• Understanding the role of SGs requires methods to precisely control their activity in live cells.
• Current methods for spatiotemporal inactivation of SGs are limited.

Purpose of the Study:

• To demonstrate the efficacy of chromophore-associated light inactivation (CALI) for spatiotemporal inactivation of SGs.
• To investigate the impact of SG inactivation on cell viability and recovery from hyperosmotic stress.
• To establish CALI as a tool for studying the function of intracellular condensates.

Main Methods:

• Utilized genetically encoded red fluorescence protein (SuperNova-Red) as a photosensitizer for CALI.
• Applied CALI to induce spatiotemporal inactivation of SGs in live cells.
• Monitored SG disassembly kinetics and cell viability during recovery from hyperosmotic stress.

Main Results:

• CALI effectively inactivated SGs, leading to delayed disassembly kinetics during recovery.
• CALI-induced SG inactivation resulted in observable differences in cell viability.
• Demonstrated CALI's capability to spatiotemporally control intracellular condensates.

Conclusions:

• CALI is a viable and effective method for the spatiotemporal inactivation of stress granules in live cells.
• This technique enables the analysis of cellular fate and phenotypes influenced by SGs.
• CALI offers a powerful new approach to elucidate the importance of intracellular condensates and aggregates.