Functional expression of the calcium release channel from skeletal muscle ryanodine receptor cDNA

[摘要]

Combined patch-clamp and fura-2 measurements were performed to study the calcium release properties of Chinese hamster ovary (CHO) cells transfected with the rabbit skeletal muscle ryanodine receptor cDNA carried by an expression vector. Both caffeine (1–50 mM) and ryanodine (100 μM) induced release of calcium from intracellular stores of transformed CHO cells but not from control (non-transfected) CHO cells. The calcium responses to caffeine and ryanodine closely resembled those commonly observed in skeletal muscle. Repetitive applications of caffeine produced characteristic all-or-none rises in intracellular calcium. Inositol 1,4,5-trisphosphate (IP₃) neither activated the ryanodine receptor channel nor interfered with the caffeine-elicited calcium release. These results indicate that functional calcium release channels are formed by expression of the ryanodine receptor cDNA.

[学科分类] 生物化学/生物物理

[关键词] cDNA expression;Ryanodine receptor;Calcium release channel;Caffeine;Fura-2;(Chinese hamster ovary cell);CHO cell;Chinese hamster ovary cell;SR;sarcoplasmic reticulum;[Ca]i;intracellular calcium concentration;ip3;inositol 1;4;5-trisphosphate;GTPγS;guanosine 5'-O-3-thiotriphosphate