Localization and functional properties of a rat brain alpha 1A calcium channel reflect similarities to neuronal Q- and P-type channels
| Autor: | Steven R. Vincent, Stefan J. Dubel, Emmanuel Bourinet, W J Tomlinson, Tuck Wah Soong, Terry P. Snutch, Anthony Stea |
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| Rok vydání: | 1994 |
| Předmět: |
Cerebellum
DNA Complementary Macromolecular Substances Gene Expression Mollusk Venoms Spider Venoms omega-Conotoxins Cav2.1 Xenopus laevis omega-Agatoxin IVA omega-Conotoxin GVIA medicine Animals Omega-Conotoxin GVIA In Situ Hybridization Cell Nucleus Neurons Multidisciplinary biology Voltage-dependent calcium channel Calcium channel Dentate gyrus Brain Membrane Proteins RNA Probes 3-Pyridinecarboxylic acid 1 4-dihydro-2 6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)- Methyl ester Calcium Channel Blockers Omega-Conotoxins Rats Olfactory bulb medicine.anatomical_structure Biochemistry Organ Specificity Oocytes biology.protein Biophysics Female Calcium Channels Peptides Research Article Plasmids |
| Zdroj: | Proceedings of the National Academy of Sciences. 91:10576-10580 |
| ISSN: | 1091-6490 0027-8424 |
| DOI: | 10.1073/pnas.91.22.10576 |
| Popis: | Functional expression of the rat brain alpha 1A Ca channel was obtained by nuclear injection of an expression plasmid into Xenopus oocytes. The alpha 1A Ca current activated quickly, inactivated slowly, and showed a voltage dependence typical of high voltage-activated Ca channels. The alpha 1A current was partially blocked (approximately 23%) by omega-agatoxin IVA (200 nM) and substantially blocked by omega-conotoxin MVIIC (5 microM blocked approximately 70%). Bay K 8644 (10 microM) or omega-conotoxin GVIA (1 microM) had no significant effect on the alpha 1A current. Coexpression with rat brain Ca channel beta subunits increased the alpha 1A whole-cell current and shifted the current-voltage relation to more negative values. While the beta 1b and beta 3 subunits caused a significant acceleration of the alpha 1A inactivation kinetics, the beta 2a subunit dramatically slowed the inactivation of the alpha 1A current to that seen typically for P-type Ca currents. In situ localization with antisense deoxyoligonucleotide and RNA probes showed that alpha 1A was widely distributed throughout the rat central nervous system, with moderate to high levels in the olfactory bulb, in the cerebral cortex, and in the CA fields and dentate gyrus of the hippocampus. In the cerebellum, prominent alpha 1A expression was detected in Purkinje cells with some labeling also in granule cells. Overall, the results show that alpha 1A channels are widely expressed and share some properties with both Q- and P-type channels. |
| Databáze: | OpenAIRE |
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