Stabilization of negative activation voltages of Cav1.3 L-Type Ca2+-channels by alternative splicing
| Autor: | Alexandra Pinggera, Jörg Striessnig, Petronel Tuluc, Nadja T. Hofer, Yuliia V. Nikonishyna, Gerald J. Obermair, Eva Maria Fritz |
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| Rok vydání: | 2020 |
| Předmět: |
0301 basic medicine
Calcium Channels L-Type Biophysics Biochemistry Cav1.3 Mice 03 medical and health sciences 0302 clinical medicine Animals Humans L-type Physics biology Alternative splicing L type ca2 channels Exons Alternative Splicing HEK293 Cells 030104 developmental biology nervous system Key (cryptography) biology.protein disease genetics Ca2 channels Ca2+ channels Neuroscience 030217 neurology & neurosurgery Research Article Research Paper Voltage |
| Zdroj: | Channels article-version (VoR) Version of Record |
| ISSN: | 1933-6969 1933-6950 |
| Popis: | >Low voltage-activated Cav1.3 L-type Ca2+-channels are key regulators of neuronal excitability controlling neuronal development and different types of learning and memory. Their physiological functions are enabled by their negative activation voltage-range, which allows Cav1.3 to be active at subthreshold voltages. Alternative splicing in the C-terminus of their pore-forming α1-subunits gives rise to C-terminal long (Cav1.3L) and short (Cav1.3S) splice variants allowing Cav1.3S to activate at even more negative voltages than Cav1.3L. We discovered that inclusion of exons 8b, 11, and 32 in Cav1.3S further shifts activation (−3 to −4 mV) and inactivation (−4 to −6 mV) to more negative voltages as revealed by functional characterization in tsA-201 cells. We found transcripts of these exons in mouse chromaffin cells, the cochlea, and the brain. Our data further suggest that Cav1.3-containing exons 11 and 32 constitute a significant part of native channels in the brain. We therefore investigated the effect of these splice variants on human disease variants. Splicing did not prevent the gating defects of the previously reported human pathogenic variant S652L, which further shifted the voltage-dependence of activation of exon 11-containing channels by more than −12 mV. In contrast, we found no evidence for gating changes of the CACNA1D missense variant R498L, located in exon 11, which has recently been identified in a patient with an epileptic syndrome. Our data demonstrate that alternative splicing outside the C-terminus involving exons 11 and 32 contributes to channel fine-tuning by stabilizing negative activation and inactivation gating properties of wild-type and mutant Cav1.3 channels. |
| Databáze: | OpenAIRE |
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