Molecular cloning and functional characterization of a novel delayed rectifier potassium channel from channel catfish (Ictalurus punctatus): expression in taste buds
| Autor: | Nguyen D. Nguyen, Ralph B. Puchalski, Christine C. Chang, Jiesheng Kang, John H. Teeter, Stephen P. Brazier |
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| Rok vydání: | 2001 |
| Předmět: |
animal structures
biology Voltage-gated ion channel fungi Protein primary structure Anatomy Molecular cloning biology.organism_classification Biochemistry Potassium channel Cell biology Cellular and Molecular Neuroscience medicine.anatomical_structure Ictalurus Taste bud medicine Peptide sequence Catfish |
| Zdroj: | Journal of Neurochemistry. 76:1465-1474 |
| ISSN: | 0022-3042 |
| Popis: | The gustatory system of channel catfish is widely studied for its sensitivity to amino acids. As a first step in identifying the molecular components that play a role in taste transduction in catfish, we cloned the full-length cDNA for Kv2-catfish, a novel K+ channel that is expressed in taste buds. The deduced amino acid sequence is 816 residues, and shares a 56–59% sequence identity with Kv2.1 and Kv2.2, the other members of the vertebrate Kv2 subfamily of voltage-gated K+ channels. The Kv2-catfish RNA was expressed in taste buds, brain, skeletal muscle, kidney, intestine and gills, and its gene is represented as a single copy in the catfish genome. Recombinant channels expressed in Xenopus oocytes were selective for K+, and were inhibited by tetraethylammonium applied to the extracellular side of the membrane during two-electrode voltage clamp analysis with a 50% inhibitory constant of 6.1 mm. The channels showed voltage-dependent activation, and did not inactivate within 200 ms. Functionally, Kv2-catfish is a voltage-gated, delayed rectifier K+ channel, and its primary structure is the most divergent sequence identified among the vertebrate members of the Kv2 subfamily of K+ channels, being related equally well to Kv2.1 and Kv2.2. |
| Databáze: | OpenAIRE |
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