Primary structure and functional expression of the omega-conotoxin-sensitive N-type calcium channel from rabbit brain.
The complete amino acid sequence of a rabbit brain calcium channel (BIII) has been deduced by cloning and sequencing the cDNA. The open reading frame encodes 2339 amino acids, which corresponds to an M(r) of 261,167. A phylogenetic tree representing evolutionary relationships indicates that BIII is grouped together with the other rabbit brain calcium channels, BI and BII, into a subfamily that is distinct from the dihydropyridine-sensitive L-type subfamily. Transient expression in cultured skeletal muscle myotubes derived from muscular dysgenic mice demonstrates that the BIII channel mediates an omega-conotoxin-sensitive calcium current with kinetics and voltage dependence like those previously reported for whole-cell N-type current. Cell-attached patch recordings, with isotonic barium as the charge carrier, revealed distinct single channels with an average slope conductance of 14.3 pS.
Fujita
Y
Y
Department of Medical Chemistry, Kyoto University Faculty of Medicine, Japan.
Mynlieff
M
M
Dirksen
R T
RT
Kim
M S
MS
Niidome
T
T
Nakai
J
J
Friedrich
T
T
Iwabe
N
N
Miyata
T
T
Furuichi
T
T
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D001921:Brain / Q000378:metabolism*; D002121:Calcium Channel Blockers / Q000494:pharmacology; D015220:Calcium Channels / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D006651:Histocytochemistry; D017403:In Situ Hybridization; D008969:Molecular Sequence Data; D010456:Peptides, Cyclic / Q000494:pharmacology*; D011817:Rabbits; D014018:Tissue Distribution; D020960:omega-Conotoxins
D002121:Calcium Channel Blockers; D015220:Calcium Channels; D010456:Peptides, Cyclic; D020960:omega-Conotoxins; C053423:Conus magus toxin