Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
19
pubmed:dateCreated
2001-5-7
pubmed:abstractText
We identified a novel MaxiK alpha subunit splice variant (SV1) from rat myometrium that is also present in brain. SV1 has a 33-amino acid insert in the S1 transmembrane domain that does not alter S1 overall hydrophobicity, but makes the S0-S1 linker longer. SV1 was transfected in HEK293T cells and studied using immunocytochemistry and electrophysiology. In non-permeabilized cells, N-terminal c-Myc- or C-terminal green fluorescent protein-tagged SV1 displayed no surface labeling or currents. The lack of SV1 functional expression was due to endoplasmic reticulum (ER) retention as determined by colabeling experiments with a specific ER marker. To explore the functional role of SV1, we coexpressed SV1 with the alpha (human SLO) and beta1 (KCNMB1) subunits of the MaxiK channel. Coexpression of SV1 inhibited surface expression of alpha and beta1 subunits approximately 80% by trapping them in the ER. This inhibition seems to be specific for MaxiK channel subunits since SV1 was unable to prevent surface expression of the Kv4.3 channel or to interact with green fluorescent protein. These results indicate a dominant-negative role of SV1 in MaxiK channel expression. Moreover, they reveal down-regulation by splice variants as a new mechanism that may contribute to the diverse levels of MaxiK channel expression in non-excitable and excitable cells.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
11
pubmed:volume
276
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
16232-9
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:11278440-Alternative Splicing, pubmed-meshheading:11278440-Amino Acid Sequence, pubmed-meshheading:11278440-Animals, pubmed-meshheading:11278440-Base Sequence, pubmed-meshheading:11278440-Cell Line, pubmed-meshheading:11278440-DNA Primers, pubmed-meshheading:11278440-Female, pubmed-meshheading:11278440-Genetic Variation, pubmed-meshheading:11278440-Humans, pubmed-meshheading:11278440-Large-Conductance Calcium-Activated Potassium Channel..., pubmed-meshheading:11278440-Large-Conductance Calcium-Activated Potassium Channels, pubmed-meshheading:11278440-Mammals, pubmed-meshheading:11278440-Models, Molecular, pubmed-meshheading:11278440-Molecular Sequence Data, pubmed-meshheading:11278440-Myometrium, pubmed-meshheading:11278440-Potassium Channels, pubmed-meshheading:11278440-Potassium Channels, Calcium-Activated, pubmed-meshheading:11278440-Pregnancy, pubmed-meshheading:11278440-Protein Structure, Secondary, pubmed-meshheading:11278440-Protein Subunits, pubmed-meshheading:11278440-Rats, pubmed-meshheading:11278440-Recombinant Proteins, pubmed-meshheading:11278440-Reverse Transcriptase Polymerase Chain Reaction, pubmed-meshheading:11278440-Transfection
pubmed:year
2001
pubmed:articleTitle
A novel MaxiK splice variant exhibits dominant-negative properties for surface expression.
pubmed:affiliation
Departments of Anesthesiology, Physiology, and Molecular and Medical Pharmacology and the Brain Research Institute, UCLA, Los Angeles, California 90095-7115, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't