Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
13
pubmed:dateCreated
1991-5-3
pubmed:databankReference
pubmed:abstractText
A gene for a slowly activating, voltage-dependent K(+) -selective channel was designed and synthesized on the basis of its known amino acid sequence. The synthetic gene was cloned into a transcription vector, and in vitro transcribed mRNA was injected into Xenopus oocytes for electrophysiological assay of the resulting ionic currents. The currents are voltage-dependent and highly selective for K+ over Na+. The selectivity among monovalent cations follows a familiar K(+)- channel sequence: K+ greater than Rb+ greater than NH4+ greater than Cs+ much greater than Na+, Li+. The currents are inhibited by Ba2+, Cs+, and tetraethylammonium (TEA), common pore blockers of K+ channels. Open-channel blockade by Cs+ (but not by Ba2+ or TEA) depends on applied voltage. The major inhibitory effect of Ba2+ is to alter channel gating by favoring the closed state; this effect is specific for Ba2+ and is relieved by external K+. The results argue that although the polypeptide expressed is very small for a eukaryotic ion channel, 130 amino acid residues in length, the ionic currents observed are indeed mediated by a genuine K(+) -channel protein. This synthetic gene is therefore well suited for a molecular analysis of the basic mechanisms of K(+) -channel function.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
2
pubmed:volume
30
pubmed:geneSymbol
minK
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3341-6
pubmed:dateRevised
2006-4-21
pubmed:meshHeading
pubmed-meshheading:2009272-Amino Acid Sequence, pubmed-meshheading:2009272-Animals, pubmed-meshheading:2009272-Barium, pubmed-meshheading:2009272-Base Sequence, pubmed-meshheading:2009272-Binding, Competitive, pubmed-meshheading:2009272-Cesium, pubmed-meshheading:2009272-Cloning, Molecular, pubmed-meshheading:2009272-Female, pubmed-meshheading:2009272-Genes, Synthetic, pubmed-meshheading:2009272-Genetic Vectors, pubmed-meshheading:2009272-Kinetics, pubmed-meshheading:2009272-Membrane Potentials, pubmed-meshheading:2009272-Molecular Sequence Data, pubmed-meshheading:2009272-Oocytes, pubmed-meshheading:2009272-Potassium Channels, pubmed-meshheading:2009272-Restriction Mapping, pubmed-meshheading:2009272-Tetraethylammonium, pubmed-meshheading:2009272-Tetraethylammonium Compounds, pubmed-meshheading:2009272-Transcription, Genetic, pubmed-meshheading:2009272-Xenopus
pubmed:year
1991
pubmed:articleTitle
Functional characterization of a minimal K+ channel expressed from a synthetic gene.
pubmed:affiliation
Department of Biochemistry, Howard Hughes Medical Institute, Brandeis University, Waltham, Massachusetts 02254-9110.
pubmed:publicationType
Journal Article