An Autonomous Molecular Bioluminescent Reporter (AMBER) for Voltage Imaging in Freely Moving Animals
Prasanna Srinivasan1,2, Nicole M Griffin1,2, DhananjayP Thakur3,4
1Department of Electrical and Computer Engineering, University of California, Santa Barbara, CA, 93106, USA.
Advanced Biology
|November 11, 2021
Summary
Researchers developed the Autonomous Molecular BioluminEscent Reporter (AMBER), a novel genetically encoded sensor. This bioluminescent reporter indicates membrane potential changes without needing external luciferin, advancing biological imaging.
Area of Science:
- Biotechnology
- Molecular Biology
- Neuroscience
Background:
- Genetically encoded reporters are crucial for biological studies.
- Fluorescent reporters face limitations in photostability and phototoxicity.
- Existing bioluminescent reporters require exogenous luciferin, restricting applications.
Purpose of the Study:
- To engineer a novel, fully genetically encoded bioluminescent reporter for membrane potential.
- To overcome limitations of current reporters by eliminating the need for exogenous luciferin.
- To develop a voltage-gated luciferase system for dynamic biological imaging.
Main Methods:
- Engineered the Autonomous Molecular BioluminEscent Reporter (AMBER) using a modular approach.
- Coupled a voltage-sensing domain (VSD) with bacterial luciferase (luxAB).
- Utilized biophysical and biochemical methods to characterize AMBER's function and voltage-dependence.
Main Results:
- AMBER demonstrates reversible switching of bioluminescent intensity based on membrane potential.
- Depolarization leads to a significant increase in enzymatic activity and bioluminescence output (ΔL/L).
- Successfully expressed and validated AMBER in Caenorhabditis elegans neurons and muscles, reconstructing in vivo activity.
Conclusions:
- AMBER is the first fully genetically encoded bioluminescent reporter functional without exogenous luciferin.
- This voltage-gated luciferase enables real-time monitoring of membrane potential in biological systems.
- AMBER offers a powerful new tool for long-term, in vivo studies of cellular electrophysiology.
