Evidence for a role of C-terminus in Ca(2+) inactivation of skeletal muscle Ca(2+) release channel (ryanodine receptor).
Six chimeras of the skeletal muscle (RyR1) and cardiac muscle (RyR2) Ca(2+) release channels (ryanodine receptors) previously used to identify RyR1 dihydropyridine receptor interactions [Nakai et al. (1998) J. Biol. Chem. 273, 13403] were expressed in HEK293 cells to assess their Ca(2+) dependence in [(3)H]ryanodine binding and single channel measurements. The results indicate that the C-terminal one-fourth has a major role in Ca(2+) activation and inactivation of RyR1. Further, our results show that replacement of RyR1 regions with corresponding RyR2 regions can result in loss and/or reduction of [(3)H]ryanodine binding affinity while maintaining channel activity.
Nakai
J
J
Department of Information Physiology, National Institute for Physiological Sciences, Myodaiji-cho, Okazaki, Japan.
Gao
L
L
Xu
L
L
Xin
C
C
Pasek
D A
DA
Meissner
G
G
D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D006801:Humans; D018482:Muscle, Skeletal / Q000166:cytology / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012433:Ryanodine / Q000378:metabolism; D019837:Ryanodine Receptor Calcium Release Channel / Q000378:metabolism* / Q000502:physiology; D014316:Tritium
D011993:Recombinant Fusion Proteins; D019837:Ryanodine Receptor Calcium Release Channel; D014316:Tritium; D012433:Ryanodine; D002118:Calcium