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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2004-1-15
pubmed:abstractText
We have characterized electrophysiological and pharmacological properties of a stretch-activated BKca channel (SAKcaC) that was cloned from cultured chick ventricular myocytes (CCVM) and expressed in chinese hamster ovary cells (CHO) using the patch-clamp technique. Our results indicate that the cloned SAKcaC keeps most of the key properties of the native SAKcaC in CCVM, such as conductance, ion selectivity, pressure-, voltage- and Ca(2+)-dependencies. However, there was a slight difference between these channels in the effects of channel blockers, charybdotoxin (CTX) and gadolinium (Gd(3+)). The native SAKcaC was blocked in an all-or-none fashion characterized as the slow blockade, whereas the conductance of the cloned SAKcaC was gradually decreased with the blockers' concentration, without noticeable blocking noise. As the involvement of some auxiliary components was suspected in this difference, we cloned a BK beta-subunit from CCVM and coexpressed it with the cloned SAKcaC in CHO cells to examine its effects on the SAKcaC. Although the pharmacological properties of the cloned SAKcaC turned out to be very similar to the native one by the coexpression, it also significantly altered the key characteristics of SAKcaC, such as voltage- and Ca(2+)-dependencies. Therefore we concluded that the native SAKca in CCVM does not interact with the corresponding endogenous beta-subunit. The difference in pharmacological properties between the expressed SAKcaC in CHO and the native one in CCVM suggests that the native SAKca in CCVM is modulated by unknown auxiliary components.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0022-2631
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
196
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
185-200
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:14724744-Animals, pubmed-meshheading:14724744-CHO Cells, pubmed-meshheading:14724744-Calcium, pubmed-meshheading:14724744-Chick Embryo, pubmed-meshheading:14724744-Cloning, Molecular, pubmed-meshheading:14724744-Conotoxins, pubmed-meshheading:14724744-Cricetinae, pubmed-meshheading:14724744-Cricetulus, pubmed-meshheading:14724744-Dose-Response Relationship, Drug, pubmed-meshheading:14724744-Gadolinium, pubmed-meshheading:14724744-Ion Channel Gating, pubmed-meshheading:14724744-Membrane Potentials, pubmed-meshheading:14724744-Myocytes, Cardiac, pubmed-meshheading:14724744-Potassium Channels, pubmed-meshheading:14724744-Pressure, pubmed-meshheading:14724744-Recombinant Proteins, pubmed-meshheading:14724744-Signal Transduction, pubmed-meshheading:14724744-Structure-Activity Relationship, pubmed-meshheading:14724744-Tetraethylammonium, pubmed-meshheading:14724744-Ventricular Function
pubmed:year
2003
pubmed:articleTitle
Characterization of a functionally expressed stretch-activated BKca channel cloned from chick ventricular myocytes.
pubmed:affiliation
Department of Physiology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't, Evaluation Studies