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Subcellular clustering of ion channels critically affects neuronal function. Coexpression of Eag and Sh channel subunits in Xenopus oocytes leads to accelerated decay of the Sh-like transient K(+) current (Chen, M.-L., T. Hoshi, and C.-F. Wu. 1996. Neuron. 17:535-542). We report that such interaction depends critically on functional expression level (controlled by RNA injection quantities and indicated by current amplitudes) and developmental time after RNA injection. The accelerated decay became apparent 3 days after coinjection and increased thereafter. This was observed in different ionic conditions and at different voltage steps. However, decay was not accelerated at low expression levels, either within 1-2 days after injection or with reduced amounts of RNA. With sequential RNA injection, preformation of either Eag or Sh channels prevented interactions with the other subunit. The carboxyl terminus of Eag was found to be involved in accelerating, and in retarding recovery from, N-type inactivation. The interaction was reduced upon patch excision in macropatch measurements, suggesting involvement of cytosolic factors. We have reproduced the absence of interaction between Eag and Sh reported previously within 2 days after RNA injection and with low levels of current expression (Tang, C.-Y., C. T. Schulteis, R. M. Jiménez, and D. M. Papazian. 1998. Biophys. J. 75:1263-1270). Our findings demonstrate that heterologous expression of channels in Xenopus oocytes is a dynamic process influenced by cell physiology and development. These factors must be considered in interpreting the functional properties of heterologously expressed channels.
Anderson,
Nerve-induced and spontaneous redistribution of acetylcholine receptors on cultured muscle cells.
1977, Pubmed,
Xenbase
Anderson,
Nerve-induced and spontaneous redistribution of acetylcholine receptors on cultured muscle cells.
1977,
Pubmed
,
Xenbase
Barnard,
International Union of Pharmacology. XV. Subtypes of gamma-aminobutyric acidA receptors: classification on the basis of subunit structure and receptor function.
1998,
Pubmed
Chen,
Heteromultimeric interactions among K+ channel subunits from Shaker and eag families in Xenopus oocytes.
1996,
Pubmed
,
Xenbase
Covarrubias,
Shaker, Shal, Shab, and Shaw express independent K+ current systems.
1991,
Pubmed
,
Xenbase
Frank,
Early events in neuromuscular junction formation in vitro: induction of acetylcholine receptor clusters in the postsynaptic membrane and morphology of newly formed synapses.
1979,
Pubmed
Ganetzky,
The eag family of K+ channels in Drosophila and mammals.
1999,
Pubmed
Guillemare,
Effects of the level of mRNA expression on biophysical properties, sensitivity to neurotoxins, and regulation of the brain delayed-rectifier K+ channels Kv1.2.
1992,
Pubmed
,
Xenbase
Haugland,
A voltage-clamp analysis of gene-dosage effects of the Shaker locus on larval muscle potassium currents in Drosophila.
1990,
Pubmed
Honoré,
Different types of K+ channel current are generated by different levels of a single mRNA.
1992,
Pubmed
,
Xenbase
Hoshi,
Two types of inactivation in Shaker K+ channels: effects of alterations in the carboxy-terminal region.
1991,
Pubmed
,
Xenbase
Isacoff,
Evidence for the formation of heteromultimeric potassium channels in Xenopus oocytes.
1990,
Pubmed
,
Xenbase
Iverson,
A-type potassium channels expressed from Shaker locus cDNA.
1988,
Pubmed
,
Xenbase
Jan,
Cloned potassium channels from eukaryotes and prokaryotes.
1997,
Pubmed
Kim,
Clustering of Shaker-type K+ channels by interaction with a family of membrane-associated guanylate kinases.
1995,
Pubmed
Li,
Specification of subunit assembly by the hydrophilic amino-terminal domain of the Shaker potassium channel.
1992,
Pubmed
Liu,
Direct protein-protein coupling enables cross-talk between dopamine D5 and gamma-aminobutyric acid A receptors.
2000,
Pubmed
Ludwig,
Carboxy-terminal domain mediates assembly of the voltage-gated rat ether-à-go-go potassium channel.
1997,
Pubmed
MacKinnon,
Determination of the subunit stoichiometry of a voltage-activated potassium channel.
1991,
Pubmed
,
Xenbase
McCormack,
Shaker K+ channel subunits from heteromultimeric channels with novel functional properties.
1990,
Pubmed
,
Xenbase
Monyer,
Heteromeric NMDA receptors: molecular and functional distinction of subtypes.
1992,
Pubmed
Moran,
Level of expression controls modes of gating of a K+ channel.
1992,
Pubmed
,
Xenbase
Niethammer,
Interaction between the C terminus of NMDA receptor subunits and multiple members of the PSD-95 family of membrane-associated guanylate kinases.
1996,
Pubmed
Papazian,
Potassium channels: some assembly required.
1999,
Pubmed
Pardo,
Oncogenic potential of EAG K(+) channels.
1999,
Pubmed
Pongs,
Shaker encodes a family of putative potassium channel proteins in the nervous system of Drosophila.
1988,
Pubmed
Rudy,
Diversity and ubiquity of K channels.
1988,
Pubmed
Salkoff,
Genetic modification of potassium channels in Drosophila Shaker mutants.
,
Pubmed
Sanguinetti,
A mechanistic link between an inherited and an acquired cardiac arrhythmia: HERG encodes the IKr potassium channel.
1995,
Pubmed
,
Xenbase
Schwarz,
Multiple potassium-channel components are produced by alternative splicing at the Shaker locus in Drosophila.
1988,
Pubmed
Sheng,
Changing subunit composition of heteromeric NMDA receptors during development of rat cortex.
1994,
Pubmed
Silverman,
A regenerative link in the ionic fluxes through the weaver potassium channel underlies the pathophysiology of the mutation.
1996,
Pubmed
,
Xenbase
Singh,
Unmasking of a novel potassium current in Drosophila by a mutation and drugs.
1999,
Pubmed
Taleb,
Expression of the human glycine receptor alpha 1 subunit in Xenopus oocytes: apparent affinities of agonists increase at high receptor density.
1994,
Pubmed
,
Xenbase
Tang,
Shaker and ether-à-go-go K+ channel subunits fail to coassemble in Xenopus oocytes.
1998,
Pubmed
,
Xenbase
Tejedor,
Essential role for dlg in synaptic clustering of Shaker K+ channels in vivo.
1997,
Pubmed
Terlau,
Extracellular Mg2+ regulates activation of rat eag potassium channel.
1996,
Pubmed
,
Xenbase
Timpe,
Four cDNA clones from the Shaker locus of Drosophila induce kinetically distinct A-type potassium currents in Xenopus oocytes.
1988,
Pubmed
,
Xenbase
Wang,
Heteromultimeric K+ channels in terminal and juxtaparanodal regions of neurons.
1993,
Pubmed
,
Xenbase
Warmke,
A distinct potassium channel polypeptide encoded by the Drosophila eag locus.
1991,
Pubmed
Wei,
K+ current diversity is produced by an extended gene family conserved in Drosophila and mouse.
1990,
Pubmed
,
Xenbase
Wu,
Potassium currents in Drosophila: different components affected by mutations of two genes.
1983,
Pubmed
Wu,
Neurogenetic studies of ion channels in Drosophila.
1992,
Pubmed
Wu,
Voltage clamp analysis of membrane currents in larval muscle fibers of Drosophila: alteration of potassium currents in Shaker mutants.
1985,
Pubmed
Wu,
Co-assembly of potassium channel subunits in Drosophila: the combinatorial hypothesis revisited.
1995,
Pubmed
,
Xenbase
Zerr,
Episodic ataxia mutations in Kv1.1 alter potassium channel function by dominant negative effects or haploinsufficiency.
1998,
Pubmed
,
Xenbase
Zhong,
Alteration of four identified K+ currents in Drosophila muscle by mutations in eag.
1991,
Pubmed
Zhong,
Modulation of different K+ currents in Drosophila: a hypothetical role for the Eag subunit in multimeric K+ channels.
1993,
Pubmed
