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Ciliary localization of a light-activated neuronal GPCR shapes behavior
Amy M Winans1, Drew Friedmann1, Cherise Stanley1
1Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720.
Summary
Primary cilia in neurons act as signaling hubs. Activating vertebrate ancient long opsin A (VALopA) in zebrafish spinal neurons via light prolonged and amplified locomotive responses, suggesting enhanced G-protein-coupled receptor signaling.
Area of Science:
- Neuroscience
- Cell Biology
- Molecular Biology
Background:
- Primary cilia are crucial signaling organelles in central nervous system neurons.
- The role of G-protein-coupled receptor (GPCR) signaling within primary cilia on circuit function and behavior remains largely unknown.
- Extraretinal opsins, like VALopA, are GPCRs that can be activated by light.
Purpose of the Study:
- To investigate the function of vertebrate ancient long opsin A (VALopA) in primary cilia of zebrafish spinal neurons.
- To determine how ciliary localization of GPCRs impacts neuronal signaling and behavior.
- To elucidate the mechanism by which VALopA influences locomotion.
Main Methods:
- Utilized zebrafish as a model organism for studying neuronal circuits and behavior.
- Investigated the localization of VALopA and VALopB in primary cilia of spinal neurons.
- Employed light activation to study the function of VALopA and VALopB.
- Performed retargeting experiments to assess the impact of ciliary localization on signaling.
Main Results:
- Vertebrate ancient long opsin A (VALopA), a Gi-coupled GPCR, targets to primary cilia in zebrafish spinal neurons.
- Light activation of VALopA in locomotion circuits inhibits coiling, the earliest form of locomotion.
- Retargeting VALopA and VALopB to cilia prolonged and amplified the locomotive response, indicating enhanced GPCR signaling.
- VALopB, a related opsin, is also Gi-coupled but does not target cilia, exhibiting faster coiling suppression kinetics.
Conclusions:
- Ciliary localization of GPCRs, such as VALopA, enhances signaling in central neurons.
- Primary cilia serve as specialized compartments for amplifying neuromodulatory GPCR signaling.
- This study provides insights into the functional significance of primary cilia in neuronal circuit regulation and behavior.
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