A new class of noninactivating K+ channels from aplysia capable of contributing to the resting potential and firing patterns of neurons

Zhao, Biao; Rassendren, François; Kaang, Bong‐Kiun; Furukawa, Yasuo; Kubo, Tai; Kandel, Eric R.

doi:10.1016/0896-6273(94)90058-2

Cited by 53 publications

(22 citation statements)

References 23 publications

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“…At least two additional ␣-subunits, unable to produce functional K ϩ currents, have been cloned (Drewe et al, 1992). The sequence homology among ␣-subunits of the same family is Ͼ70%, but this value decreases to Ͻ50% among members of different families (Kamb et al, 1987;Papazian et al, 1987;Pongs et al, 1988;Stühmer et al, 1989;Drewe et al, 1992;Salkoff et al, 1992;Chandy and Gutman, 1993;Zhao et al, 1994). The marked functional variability of the K ϩ currents, a characteristic particularly apparent in mammalian neurons (Llinás, 1988;Rudy, 1988), arises from several mechanisms.…”

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confidence: 99%

Identification and Functional Characterization of a K⁺Channel α-Subunit with Regulatory Properties Specific to Brain

et al. 1997

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The physiological diversity of K ϩ channels mainly depends on the expression of several genes encoding different ␣-subunits. We have cloned a new K ϩ channel ␣-subunit (Kv2.3r) that is unable to form functional channels on its own but that has a major regulatory function. Kv2.3r can coassemble selectively with other ␣-subunits to form functional heteromultimeric K ϩ channels with kinetic properties that differ from those of the parent channels. Kv2.3r is expressed exclusively in the brain, being concentrated particularly in neocortical neurons. The functional expression of this regulatory ␣-subunit represents a novel mechanism without precedents in voltage-gated channels, which might contribute to further increase the functional diversity of K ϩ channels necessary to specify the intrinsic electrical properties of individual neurons.

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confidence: 99%

Identification and Functional Characterization of a K⁺Channel α-Subunit with Regulatory Properties Specific to Brain

et al. 1997

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“…Kv channels belong to the six-transmembrane (TM) family of K channels, where Kv1 to Kv11 subfamilies exist, although Kv7 is only found in Aplysia (22,23). Members of the Kv1 to Kv4 subfamilies form tetrameric functional channels, homomultimers or heteromultimers, usually with members from the same subfamily.…”

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confidence: 99%

Expression of Voltage-Gated Potassium Channels in Human and Rhesus Pancreatic Islets

et al. 2004

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Voltage-gated potassium channels (Kv channels) are involved in repolarization of excitable cells. In pancreatic ␤-cells, prolongation of the action potential by block of delayed rectifier potassium channels would be expected to increase intracellular free calcium and to promote insulin release in a glucose-dependent manner. However, the specific Kv channel subtypes responsible for repolarization in ␤-cells, most importantly in humans, are not completely resolved. In this study, we have investigated the expression of 26 subtypes from Kv subfamilies in human islet mRNA. The results of the RT-PCR analysis were extended by in situ hybridization and/or immunohistochemical analysis on sections from human or Rhesus pancreas. Cell-specific markers were used to show that Kv2.1, Kv3.2, Kv6.2, and Kv9.3 are expressed in ␤-cells, that Kv3.1 and Kv6.1 are expressed in ␣-cells , and that Kv2.2 is expressed in ␦-cells. This study suggests that more than one Kv channel subtype might contribute to the ␤-cell delayed rectifier current and that this current could be formed by heterotetramers of active and silent subunits. Diabetes 53: 597-607, 2004

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“…These are divided into subfamilies by sequence similarities: within a subfamily members share Ϸ70% of sequence identity, whereas between different subfamilies this percentage drops to Ϸ40%, reflecting the homology in the core section S1-S6 (4). The Kv family of potassium channels consists of nine subfamilies, Kv1 through Kv9, although Kv7 has only been described for Aplysia (5). The subunits of the Kv1 through Kv4 subfamilies all show functional expression in a homotetrameric configuration.…”

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Obligatory heterotetramerization of three previously uncharacterized Kv channel α-subunits identified in the human genome

Ottschytsch

Raes²,

Hoorick³

et al. 2002

Proc. Natl. Acad. Sci. U.S.A.

156

182

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Voltage-gated K ؉ channels control excitability in neuronal and various other tissues. We identified three unique ␣-subunits of voltage-gated K ؉ -channels in the human genome. Analysis of the full-length sequences indicated that one represents a previously uncharacterized member of the Kv6 subfamily, Kv6.3, whereas the others are the first members of two unique subfamilies, Kv10.1 and Kv11.1. Although they have all of the hallmarks of voltage-gated K ؉ channel subunits, they did not produce K ؉ currents when expressed in mammalian cells. Confocal microscopy showed that Kv6.3, Kv10.1, and Kv11.1 alone did not reach the plasma membrane, but were retained in the endoplasmic reticulum. Yeast two-hybrid experiments failed to show homotetrameric interactions, but showed interactions with Kv2.1, Kv3.1, and Kv5.1. Co-expression of each of the previously uncharacterized subunits with Kv2.1 resulted in plasma membrane localization with currents that differed from typical Kv2.1 currents. This heteromerization was confirmed by co-immunoprecipitation. The Kv2 subfamily consists of only two members and uses interaction with ''silent subunits'' to diversify its function. Including the subunits described here, the ''silent subunits'' represent one-third of all Kv subunits, suggesting that obligatory heterotetramer formation is more widespread than previously thought.electrically silent subunits ͉ ER retention ͉ heterotetrameric assembly ͉ KCNG3

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A new class of noninactivating K+ channels from aplysia capable of contributing to the resting potential and firing patterns of neurons

Cited by 53 publications

References 23 publications

Identification and Functional Characterization of a K⁺Channel α-Subunit with Regulatory Properties Specific to Brain

Identification and Functional Characterization of a K⁺Channel α-Subunit with Regulatory Properties Specific to Brain

Expression of Voltage-Gated Potassium Channels in Human and Rhesus Pancreatic Islets

Obligatory heterotetramerization of three previously uncharacterized Kv channel α-subunits identified in the human genome

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A new class of noninactivating K+ channels from aplysia capable of contributing to the resting potential and firing patterns of neurons

Cited by 53 publications

References 23 publications

Identification and Functional Characterization of a K+Channel α-Subunit with Regulatory Properties Specific to Brain

Identification and Functional Characterization of a K+Channel α-Subunit with Regulatory Properties Specific to Brain

Expression of Voltage-Gated Potassium Channels in Human and Rhesus Pancreatic Islets

Obligatory heterotetramerization of three previously uncharacterized Kv channel α-subunits identified in the human genome

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Identification and Functional Characterization of a K⁺Channel α-Subunit with Regulatory Properties Specific to Brain

Identification and Functional Characterization of a K⁺Channel α-Subunit with Regulatory Properties Specific to Brain