Stable and functional expression of the calcium channel alpha 1 subunit from smooth muscle in somatic cell lines.
Voltage-activated calcium channels are membrane spanning proteins that allow the controlled entry of Ca2+ into the cytoplasm of cells. The principal channel forming subunit of an L-type calcium channel is the alpha 1 subunit. Transfection of Chinese hamster ovary (CHO) cells with complementary DNA encoding the calcium channel alpha 1 subunit from smooth muscle led to the expression of functional calcium channels which bind calcium channel blockers and show the voltage-dependent activation and slow inactivation and unitary current conductance characteristic of calcium channels in smooth muscle. The currents mediated by these channels are sensitive towards dihydropyridine-type blockers and agonists indicating that the calcium channel blocker receptor sites were present in functional form. The smooth muscle alpha 1 subunit cDNA alone is sufficient for stable expression of functional calcium channels with the expected kinetic and pharmacological properties in mammalian somatic cells.
Bosse
E
E
Institut für Pharmakologie und Toxikologie, Technische Universität München, FRG.
Bottlender
R
R
Kleppisch
T
T
Hescheler
J
J
Welling
A
A
Hofmann
F
F
Flockerzi
V
V
D000818:Animals; D001483:Base Sequence; D016466:CHO Cells; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D015220:Calcium Channels / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D006224:Cricetinae; D004247:DNA / Q000235:genetics; D004095:Dihydropyridines / Q000378:metabolism; D015640:Ion Channel Gating; D017275:Isradipine; D007700:Kinetics; D046911:Macromolecular Substances; D008564:Membrane Potentials; D008969:Molecular Sequence Data; D009130:Muscle, Smooth / Q000502:physiology*; D009132:Muscles / Q000502:physiology*; D009838:Oligodeoxyribonucleotides; D011061:Poly A / Q000235:genetics / Q000302:isolation & purification; D016133:Polymerase Chain Reaction; D012313:RNA / Q000235:genetics / Q000302:isolation & purification; D012333:RNA, Messenger; D011994:Recombinant Proteins / Q000187:drug effects / Q000378:metabolism; D015183:Restriction Mapping; D014162:Transfection
D002121:Calcium Channel Blockers; D015220:Calcium Channels; D004095:Dihydropyridines; D046911:Macromolecular Substances; D009838:Oligodeoxyribonucleotides; D012333:RNA, Messenger; D011994:Recombinant Proteins; D011061:Poly A; D012313:RNA; D004247:DNA; D017275:Isradipine