Generation of cell transfectants expressing cardiac calcium ion channel and calcium indicator protein aequorin.
Chinese hamster ovary (CHO) cells stably coexpressing cardiac calcium ion channel [L-type calcium channel or ryanodine receptor (RyR)] and the calcium-sensitive bioluminescent protein aequorin were generated by transfecting aequorin cDNA. In a selected clone, C1-17, carrying the L-type calcium channel, depolarization induced by high concentration of K+ produces aequorin luminescence. In another clone, R3-7, carrying RyR, caffeine produces aequorin luminescence. In the presence of selective calcium ion channel blockers, the aequorin luminescence was inhibited in a dose-dependent manner. These results indicate that functionally expressed calcium ion channels in these transformants can be monitored through the activation of endogenous aequorin luminescence following a physiological signal similar to that of native calcium channel. Moreover, the aequorin system compared very well with Fura-2 measurements. Thus, the recombinant cell models, which expressed cloned calcium channel and aequorin, will contribute to the elucidation of Ca2+ movement through the cell surface and intracellular calcium ion channels.
Maeda
A
A
Department of Molecular and Cellular Biology, Nippon Boehringer Ingelheim Co., Ltd., Kawanishi Pharma Research Institute, Hyogo, Japan.
Nishimura
S
S
Kameda
K
K
Imagawa
T
T
Shigekawa
M
M
Barsoumian
E L
EL
D000331:Aequorin / Q000032:analysis* / Q000235:genetics; D000818:Animals; D016466:CHO Cells; D002110:Caffeine / Q000494:pharmacology; D002118:Calcium / Q000032:analysis*; D002121:Calcium Channel Blockers / Q000494:pharmacology; D015220:Calcium Channels / Q000235:genetics / Q000378:metabolism*; D002999:Clone Cells; D006224:Cricetinae; D018076:DNA, Complementary / Q000235:genetics; D004305:Dose-Response Relationship, Drug; D016257:Fura-2; D008163:Luminescent Measurements; D009124:Muscle Proteins / Q000235:genetics / Q000378:metabolism; D010957:Plasmids / Q000235:genetics; D011188:Potassium / Q000494:pharmacology; D019837:Ryanodine Receptor Calcium Release Channel; D014162:Transfection
D002121:Calcium Channel Blockers; D015220:Calcium Channels; D018076:DNA, Complementary; D009124:Muscle Proteins; D019837:Ryanodine Receptor Calcium Release Channel; D002110:Caffeine; D000331:Aequorin; D011188:Potassium; D002118:Calcium; D016257:Fura-2