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Siller A, Hofer NT, Tomagra G, Burkert N, Hess S, Benkert J, Gaifullina A, Spaich D, Duda J, Poetschke C, Vilusic K, Fritz EM, Schneider T, Kloppenburg P, Liss B, Carabelli V, Carbone E, Ortner NJ, Striessnig J. β2-subunit alternative splicing stabilizes Cav2.3 Ca 2+ channel activity during continuous midbrain dopamine neuron-like activity. eLife 2022; 11:e67464. [PMID: 35792082 PMCID: PMC9307272 DOI: 10.7554/elife.67464] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 07/04/2022] [Indexed: 11/13/2022] Open
Abstract
In dopaminergic (DA) Substantia nigra (SN) neurons Cav2.3 R-type Ca2+-currents contribute to somatodendritic Ca2+-oscillations. This activity may contribute to the selective degeneration of these neurons in Parkinson's disease (PD) since Cav2.3-knockout is neuroprotective in a PD mouse model. Here, we show that in tsA-201-cells the membrane-anchored β2-splice variants β2a and β2e are required to stabilize Cav2.3 gating properties allowing sustained Cav2.3 availability during simulated pacemaking and enhanced Ca2+-currents during bursts. We confirmed the expression of β2a- and β2e-subunit transcripts in the mouse SN and in identified SN DA neurons. Patch-clamp recordings of mouse DA midbrain neurons in culture and SN DA neurons in brain slices revealed SNX-482-sensitive R-type Ca2+-currents with voltage-dependent gating properties that suggest modulation by β2a- and/or β2e-subunits. Thus, β-subunit alternative splicing may prevent a fraction of Cav2.3 channels from inactivation in continuously active, highly vulnerable SN DA neurons, thereby also supporting Ca2+ signals contributing to the (patho)physiological role of Cav2.3 channels in PD.
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Affiliation(s)
- Anita Siller
- Department of Pharmacology and Toxicology, Institute of Pharmacy, Center for Molecular Biosciences Innsbruck, University of InnsbruckInnsbruckAustria
| | - Nadja T Hofer
- Department of Pharmacology and Toxicology, Institute of Pharmacy, Center for Molecular Biosciences Innsbruck, University of InnsbruckInnsbruckAustria
| | - Giulia Tomagra
- Department of Drug Science, NIS Centre, University of TorinoTorinoItaly
| | - Nicole Burkert
- Institute of Applied Physiology, University of Ulm, Ulm, GermanyUlmGermany
| | - Simon Hess
- Institute for Zoology, Biocenter, University of CologneCologneGermany
| | - Julia Benkert
- Institute of Applied Physiology, University of Ulm, Ulm, GermanyUlmGermany
| | - Aisylu Gaifullina
- Institute of Applied Physiology, University of Ulm, Ulm, GermanyUlmGermany
| | - Desiree Spaich
- Institute of Applied Physiology, University of Ulm, Ulm, GermanyUlmGermany
| | - Johanna Duda
- Institute of Applied Physiology, University of Ulm, Ulm, GermanyUlmGermany
| | | | - Kristina Vilusic
- Department of Pharmacology and Toxicology, Institute of Pharmacy, Center for Molecular Biosciences Innsbruck, University of InnsbruckInnsbruckAustria
| | - Eva Maria Fritz
- Department of Pharmacology and Toxicology, Institute of Pharmacy, Center for Molecular Biosciences Innsbruck, University of InnsbruckInnsbruckAustria
| | - Toni Schneider
- Institute of Neurophysiology, University of CologneCologneGermany
| | - Peter Kloppenburg
- Institute for Zoology, Biocenter, University of CologneCologneGermany
| | - Birgit Liss
- Institute of Applied Physiology, University of Ulm, Ulm, GermanyUlmGermany
- Linacre College & New College, University of OxfordOxfordUnited Kingdom
| | | | - Emilio Carbone
- Department of Drug Science, NIS Centre, University of TorinoTorinoItaly
| | - Nadine Jasmin Ortner
- Department of Pharmacology and Toxicology, Institute of Pharmacy, Center for Molecular Biosciences Innsbruck, University of InnsbruckInnsbruckAustria
| | - Jörg Striessnig
- Department of Pharmacology and Toxicology, Institute of Pharmacy, Center for Molecular Biosciences Innsbruck, University of InnsbruckInnsbruckAustria
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