Single Fluorescent Protein-Based Indicators for Zinc Ion (Zn(2+))

Area of Science:

• Cellular biology
• Biochemistry
• Molecular imaging

Background:

• Genetically encoded fluorescent Zn(2+) indicators (GEZIs) are crucial for studying zinc homeostasis and signaling.
• Current Förster resonance energy transfer (FRET)-based GEZIs have limitations due to broad spectral bandwidths, hindering multicolor applications.
• There is a need for advanced GEZIs that overcome spectral overlap issues for complex cellular imaging.

Purpose of the Study:

• To engineer novel intensiometric GEZIs based on single teal and red fluorescent proteins.
• To overcome the spectral limitations of traditional FRET-based GEZIs.
• To enable robust monitoring of subcellular zinc diffusion and secretion in pancreatic β-cells.

Main Methods:

• Engineering of intensiometric GEZIs utilizing single teal and red fluorescent proteins fused with zinc-binding motifs.
• Application of novel GEZIs for monitoring subcellular zinc diffusion in pancreatic INS-1E β-cells.
• Utilizing GEZIs to track glucose-induced zinc secretion in pancreatic β-cells.

Main Results:

• Successful engineering of intensiometric GEZIs based on single teal and red fluorescent proteins.
• Demonstrated utility of new GEZIs for monitoring subcellular zinc dynamics.
• Observed glucose-induced zinc secretion in pancreatic INS-1E β-cells using the developed GEZIs.
• New GEZIs exhibit large dynamic ranges and compatibility with multicolor imaging.

Conclusions:

• The developed intensiometric GEZIs offer a simplified and versatile approach for zinc imaging.
• These novel GEZIs are valuable tools for studying cellular zinc signaling and homeostasis.
• The single-FP-based design overcomes spectral limitations, facilitating multicolor imaging applications.