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Slaviero A, Gorantla N, Simkins J, Crespo EL, Ikefuama EC, Tree MO, Prakash M, Björefeldt A, Barnett LM, Lambert GG, Lipscombe D, Moore CI, Shaner NC, Hochgeschwender U. Engineering luminopsins with improved coupling efficiencies. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.22.568342. [PMID: 38045286 PMCID: PMC10690276 DOI: 10.1101/2023.11.22.568342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2023]
Abstract
Significance Luminopsins (LMOs) are bioluminescent-optogenetic tools with a luciferase fused to an opsin that allow bimodal control of neurons by providing both optogenetic and chemogenetic access. Determining which design features contribute to the efficacy of LMOs will be beneficial for further improving LMOs for use in research. Aim We investigated the relative impact of luciferase brightness, opsin sensitivity, pairing of emission and absorption wavelength, and arrangement of moieties on the function of LMOs. Approach We quantified efficacy of LMOs through whole cell patch clamp recordings in HEK293 cells by determining coupling efficiency, the percentage of maximum LED induced photocurrent achieved with bioluminescent activation of an opsin. We confirmed key results by multielectrode array (MEAs) recordings in primary neurons. Results Luciferase brightness and opsin sensitivity had the most impact on the efficacy of LMOs, and N-terminal fusions of luciferases to opsins performed better than C-terminal and multi-terminal fusions. Precise paring of luciferase emission and opsin absorption spectra appeared to be less critical. Conclusions Whole cell patch clamp recordings allowed us to quantify the impact of different characteristics of LMOs on their function. Our results suggest that coupling brighter bioluminescent sources to more sensitive opsins will improve LMO function. As bioluminescent activation of opsins is most likely based on Förster resonance energy transfer (FRET), the most effective strategy for improving LMOs further will be molecular evolution of luciferase-fluorescent protein-opsin fusions.
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Affiliation(s)
- Ashley Slaviero
- Central Michigan University, College of Medicine, Mount Pleasant, Michigan, United States
- Central Michigan University, Biochemistry, Cellular and Molecular Biology Graduate Program, Mount Pleasant, Michigan, United States
| | - Nipun Gorantla
- Central Michigan University, College of Medicine, Mount Pleasant, Michigan, United States
| | - Jacob Simkins
- Central Michigan University, College of Medicine, Mount Pleasant, Michigan, United States
| | - Emmanuel L Crespo
- Central Michigan University, College of Medicine, Mount Pleasant, Michigan, United States
- Central Michigan University, Biochemistry, Cellular and Molecular Biology Graduate Program, Mount Pleasant, Michigan, United States
| | - Ebenezer C Ikefuama
- Central Michigan University, College of Medicine, Mount Pleasant, Michigan, United States
- Central Michigan University, Neuroscience Graduate Program, Mount Pleasant, Michigan, United States
| | - Maya O Tree
- Central Michigan University, College of Medicine, Mount Pleasant, Michigan, United States
| | - Mansi Prakash
- Central Michigan University, College of Medicine, Mount Pleasant, Michigan, United States
| | - Andreas Björefeldt
- Central Michigan University, College of Medicine, Mount Pleasant, Michigan, United States
| | - Lauren M Barnett
- University of California San Diego, Department of Neurosciences, La Jolla, California, United States
| | - Gerard G Lambert
- University of California San Diego, Department of Neurosciences, La Jolla, California, United States
| | - Diane Lipscombe
- Brown University, Carney Institute for Brain Science, Providence, Rhode Island, United States
| | - Christopher I Moore
- Brown University, Carney Institute for Brain Science, Providence, Rhode Island, United States
| | - Nathan C Shaner
- University of California San Diego, Department of Neurosciences, La Jolla, California, United States
| | - Ute Hochgeschwender
- Central Michigan University, College of Medicine, Mount Pleasant, Michigan, United States
- Central Michigan University, Biochemistry, Cellular and Molecular Biology Graduate Program, Mount Pleasant, Michigan, United States
- Central Michigan University, Neuroscience Graduate Program, Mount Pleasant, Michigan, United States
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Petersen ED, Lapan AP, Castellanos Franco EA, Fillion AJ, Crespo EL, Lambert GG, Grady CJ, Zanca AT, Orcutt R, Hochgeschwender U, Shaner NC, Gilad AA. Bioluminescent Genetically Encoded Glutamate Indicators for Molecular Imaging of Neuronal Activity. ACS Synth Biol 2023; 12:2301-2309. [PMID: 37450884 PMCID: PMC10443529 DOI: 10.1021/acssynbio.2c00687] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Indexed: 07/18/2023]
Abstract
Genetically encoded optical sensors and advancements in microscopy instrumentation and techniques have revolutionized the scientific toolbox available for probing complex biological processes such as release of specific neurotransmitters. Most genetically encoded optical sensors currently used are based on fluorescence and have been highly successful tools for single-cell imaging in superficial brain regions. However, there remains a need to develop new tools for reporting neuronal activity in vivo within deeper structures without the need for hardware such as lenses or fibers to be implanted within the brain. Our approach to this problem is to replace the fluorescent elements of the existing biosensors with bioluminescent elements. This eliminates the need of external light sources to illuminate the sensor, thus allowing deeper brain regions to be imaged noninvasively. Here, we report the development of the first genetically encoded neurotransmitter indicators based on bioluminescent light emission. These probes were optimized by high-throughput screening of linker libraries. The selected probes exhibit robust changes in light output in response to the extracellular presence of the excitatory neurotransmitter glutamate. We expect this new approach to neurotransmitter indicator design to enable the engineering of specific bioluminescent probes for multiple additional neurotransmitters in the future, ultimately allowing neuroscientists to monitor activity associated with a specific neurotransmitter as it relates to behavior in a variety of neuronal and psychiatric disorders, among many other applications.
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Affiliation(s)
- Eric D. Petersen
- Department
of Chemical Engineering and Materials Science, Michigan State University, East Lansing, Michigan 48824, United States
- College
of Medicine, Central Michigan University, Mount Pleasant, Michigan 48859, United States
| | - Alexandra P. Lapan
- Department
of Chemical Engineering and Materials Science, Michigan State University, East Lansing, Michigan 48824, United States
| | | | - Adam J. Fillion
- Department
of Chemical Engineering and Materials Science, Michigan State University, East Lansing, Michigan 48824, United States
| | - Emmanuel L. Crespo
- College
of Medicine, Central Michigan University, Mount Pleasant, Michigan 48859, United States
| | - Gerard G. Lambert
- Department
of Neurosciences, University of California
San Diego School of Medicine, La Jolla, California 92093, United States
| | - Connor J. Grady
- Department
of Biomedical Engineering, Michigan State
University, East Lansing, Michigan 48824, United States
| | - Albertina T. Zanca
- Department
of Neurosciences, University of California
San Diego School of Medicine, La Jolla, California 92093, United States
| | - Richard Orcutt
- Department
of Neurosciences, University of California
San Diego School of Medicine, La Jolla, California 92093, United States
| | - Ute Hochgeschwender
- College
of Medicine, Central Michigan University, Mount Pleasant, Michigan 48859, United States
| | - Nathan C. Shaner
- Department
of Neurosciences, University of California
San Diego School of Medicine, La Jolla, California 92093, United States
| | - Assaf A. Gilad
- Department
of Chemical Engineering and Materials Science, Michigan State University, East Lansing, Michigan 48824, United States
- Department
of Radiology, Michigan State University, East Lansing, Michigan 48824, United States
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