Linked Life Data

8107964

Source:http://linkedlifedata.com/resource/pubmed/id/8107964

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
1994-3-21
pubmed:abstractText
Voltage-dependent calcium (Ca2+) channels, expressed in the CNS, appear to be multimeric complexes comprised of at least alpha 1, alpha 2 and beta subunits. Previously, we cloned and expressed human neuronal alpha 1, alpha 2 and beta subunits to study recombinant channel complexes that display properties of those expressed in vivo. The alpha 1B-mediated channel subtype binds omega-conotoxin (CgTx) GVIA with high affinity and exhibits properties of N-type voltage-dependent Ca2+ channels. Here we describe several alpha 2 and beta splice variants and report results on the expression of omega-CgTx GVIA binding sites, assembly of the subunit complex and biophysical function of alpha 1B-mediated channel complexes containing some of these splice variants. We optimized recombinant expression in human embryonic kidney (HEK) 293 cells of alpha 1B alpha 2b beta 1 subunit complexes by controlling the expression levels of subunit mRNAs and monitored cell surface expression by binding of omega-CgTx GVIA to the alpha 1B subunit. Co-expression of either alpha 2b or beta 1 subunits with an alpha 1B subunit increased expression of binding sites while the most efficient expression was achieved when both alpha 2b and beta 1 subunits were co-expressed with an alpha 1B subunit. The presence of alpha 2b affects the affinity of omega-CgTx GVIA binding and barium (Ba2+) current magnitudes, although it does not appear to alter kinetic properties of the Ba2+ current. This is the first evidence of an alpha 2 subunit modulating the binding affinity of a cell-surface Ca2+ channel ligand. Our results demonstrate that alpha 1, alpha 2 and beta subunits together contribute to the efficient assembly and functional expression of voltage-dependent Ca2+ channel complexes.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0028-3908
pubmed:author
pubmed:issnType
Print
pubmed:volume
32
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1089-102
pubmed:dateRevised
2004-11-17
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Human neuronal voltage-dependent calcium channels: studies on subunit structure and role in channel assembly.
pubmed:affiliation
SIBIA, Inc., La Jolla, CA 92037.
pubmed:publicationType
Journal Article