Linked Life Data

7943383

Source:http://linkedlifedata.com/resource/pubmed/id/7943383

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4 Pt 2
pubmed:dateCreated
1994-11-18
pubmed:databankReference
pubmed:abstractText
FK1, a ferret ventricular full-length cDNA clone, encodes a 654-amino acid protein with 98% identity to human K+ transient outward current (Ito)-like HK1 (Tamkun et al. FASEB J.5: 331-337, 1991). FK1 is detectable in ferret brain, atrium, left and right ventricle, and kidney but not in skeletal muscle, endothelial cells, aorta, and liver. In Xenopus oocytes, FK1 cRNA gives rise to a rapidly activating and inactivating Ito-like current, which is highly K+ selective (Na(+)-to-K+ permeability ratio = 0.003). Activation occurs over an approximately 50-mV range (-40 to +10 mV) and displays a sigmoid delay in onset with potential-dependent time constants that decrease with depolarization. Steady-state activation can be described with either a simple Boltzmann relationship [half-activation potential (V1/2) = -25 mV, slope (k) = 10 mV] or a Boltzmann relationship raised to either the third or fourth power (alpha 3: V1/2 = -43 mV, kappa = 13.1 mV; alpha 4: V1/2 = -48 mV, kappa = 13.6 mV, where alpha is the activation variable). Inactivation kinetics are biexponential, with the main fast time constant becoming independent of membrane potential depolarized to 0 mV. Steady-state inactivation can be described with a single Boltzmann relationship (V1/2 = -57 mV, kappa = 5.0 mV). Fast inactivation is removed by NH2-terminal deletions. Recovery from inactivation (-90 mV) is quite slow (half-time = 4.8 +/- 2.5 s). In 2 mM extracellular K+ concentration ([K+]o), FK1 tail currents display conventional deactivation behavior; however, in 98 mM [K+]o the tail currents display "reopening" behavior. These results suggest a molecular basis for the electrophysiological similarities between ferret and human ventricular Ito (Campbell et al. J. Gen. Physiol. 101: 571-601, 1993; Näbauer et al. Circ. Res. 73: 386-394, 1993).
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
267
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
H1383-95
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:7943383-Amino Acid Sequence, pubmed-meshheading:7943383-Animals, pubmed-meshheading:7943383-Base Sequence, pubmed-meshheading:7943383-Cloning, Molecular, pubmed-meshheading:7943383-DNA, Complementary, pubmed-meshheading:7943383-DNA Primers, pubmed-meshheading:7943383-Female, pubmed-meshheading:7943383-Ferrets, pubmed-meshheading:7943383-Gene Library, pubmed-meshheading:7943383-Heart Ventricles, pubmed-meshheading:7943383-Humans, pubmed-meshheading:7943383-Kinetics, pubmed-meshheading:7943383-Male, pubmed-meshheading:7943383-Membrane Potentials, pubmed-meshheading:7943383-Molecular Sequence Data, pubmed-meshheading:7943383-Mutagenesis, Site-Directed, pubmed-meshheading:7943383-Myocardium, pubmed-meshheading:7943383-Oocytes, pubmed-meshheading:7943383-Organ Specificity, pubmed-meshheading:7943383-Potassium Channels, pubmed-meshheading:7943383-RNA, Messenger, pubmed-meshheading:7943383-Recombinant Proteins, pubmed-meshheading:7943383-Sequence Homology, Amino Acid, pubmed-meshheading:7943383-Transcription, Genetic, pubmed-meshheading:7943383-Xenopus
pubmed:year
1994
pubmed:articleTitle
Cloning and characterization of an Ito-like potassium channel from ferret ventricle.
pubmed:affiliation
Department of Pharmacology, Biomedical Engineering, Duke University Medical Center, Durham, North Carolina 27710.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S.