Linked Life Data

16423824

Source:http://linkedlifedata.com/resource/pubmed/id/16423824

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
2006-3-20
pubmed:abstractText
Native amiloride-sensitive Na+ channels exhibit a variety of biophysical properties, including variable sensitivities to amiloride, different ion selectivities, and diverse unitary conductances. The molecular basis of these differences has not been elucidated. We tested the hypothesis that co-expression of delta-epithelial sodium channel (ENaC) underlies, at least in part, the multiplicity of amiloride-sensitive Na+ conductances in epithelial cells. For example, the delta-subunit may form multimeric channels with alpha beta gamma-ENaC. Reverse transcription-PCR revealed that delta-ENaC is co-expressed with alpha beta gamma-subunits in cultured human lung (H441 and A549), pancreatic (CFPAC), and colonic epithelial cells (Caco-2). Indirect immunofluorescence microscopy revealed that delta-ENaC is co-expressed with alpha-, beta-, and gamma-ENaC in H441 cells at the protein level. Measurement of current-voltage that cation selectivity ratios for the revealed relationships Na+/Li+/K+/Cs+/Ca2+/Mg2+, the apparent dissociation constant (Ki) for amiloride, and unitary conductances for delta alpha beta gamma-ENaC differed from those of both alpha beta gamma- and delta beta gamma-ENaC (n = 6). The contribution of the delta subunit to P(Li)/P(Na) ratio and unitary Na+ conductance under bi-ionic conditions depended on the injected cRNA concentration. In addition, the EC50 for proton activation, mean open and closed times, and the self-inhibition time of delta alpha beta gamma-ENaC differed from those of alpha beta gamma- and delta beta gamma-ENaC. Co-immunoprecipitation of delta-ENaC with alpha- and gamma-subunits in H441 and transfected COS-7 cells suggests an interaction among these proteins. We, therefore, concluded that the interactions of delta-ENaC with other subunits could account for heterogeneity of native epithelial channels.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
24
pubmed:volume
281
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
8233-41
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:16423824-Amiloride, pubmed-meshheading:16423824-Animals, pubmed-meshheading:16423824-Biophysics, pubmed-meshheading:16423824-COS Cells, pubmed-meshheading:16423824-Caco-2 Cells, pubmed-meshheading:16423824-Cations, pubmed-meshheading:16423824-Cell Line, Tumor, pubmed-meshheading:16423824-Cercopithecus aethiops, pubmed-meshheading:16423824-Epithelial Sodium Channel, pubmed-meshheading:16423824-Fluorescent Antibody Technique, Indirect, pubmed-meshheading:16423824-Humans, pubmed-meshheading:16423824-Hydrogen-Ion Concentration, pubmed-meshheading:16423824-Immunoprecipitation, pubmed-meshheading:16423824-Kinetics, pubmed-meshheading:16423824-Microscopy, Fluorescence, pubmed-meshheading:16423824-Oocytes, pubmed-meshheading:16423824-Patch-Clamp Techniques, pubmed-meshheading:16423824-Protein Binding, pubmed-meshheading:16423824-Protons, pubmed-meshheading:16423824-RNA, Complementary, pubmed-meshheading:16423824-RNA, Messenger, pubmed-meshheading:16423824-Reverse Transcriptase Polymerase Chain Reaction, pubmed-meshheading:16423824-Sodium, pubmed-meshheading:16423824-Sodium Channels, pubmed-meshheading:16423824-Time Factors, pubmed-meshheading:16423824-Transfection
pubmed:year
2006
pubmed:articleTitle
Delta-subunit confers novel biophysical features to alpha beta gamma-human epithelial sodium channel (ENaC) via a physical interaction.
pubmed:affiliation
Department of Anesthesiology, University of Alabama at Birmingham, Alabama 35205, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural