Development of red genetically encoded biosensor for visualization of intracellular glucose dynamics

Area of Science:

• Cellular biology
• Biochemistry
• Molecular imaging

Background:

• Understanding intracellular glucose dynamics is crucial for energy metabolism research.
• Existing glucose indicators have limitations in live-cell and multi-color imaging applications.

Purpose of the Study:

• To develop novel red fluorescent protein-based glucose indicators (Red Glifons) for live-cell imaging.
• To enable multi-color imaging of glucose metabolism and its interplay with other metabolites.

Main Methods:

• Development of two Red Glifon variants with distinct half-maximal effective concentration (EC50) values.
• Application of Red Glifons in live-cell imaging of various cell types, including C. elegans, enteroendocrine cells, and human iPS cell-derived cardiac myocytes.
• Dual-color imaging combining Red Glifons with green indicators for co-visualization of glucose with ATP, lactate, or pyruvate.

Main Results:

• Red Glifons demonstrated a >3-fold increase in fluorescence intensity with 10 mM glucose.
• The developed indicators exhibit EC50 values of 300 μM and 3,000 μM, allowing monitoring of a wide glucose concentration range.
• Successful visualization of glucose influx in diverse biological models was achieved.

Conclusions:

• Red Glifons provide a versatile toolkit for multi-color imaging of intracellular glucose.
• These indicators facilitate the investigation of complex interactions within cellular energy metabolism.
• The Red Glifon system advances the study of glucose dynamics in live biological systems.