Expressed cerebellar-type inositol 1,4,5-trisphosphate receptor, P400, has calcium release activity in a fibroblast L cell line.
P400, inositol 1,4,5-trisphosphate receptor (InsP3-R), is a key protein to understanding the mechanisms of inositol 1,4,5-trisphosphate (InsP3)-mediated Ca2+ mobilization. We obtained the cerebellar-type P400/InsP3-R cDNA and generated an L cell transfectant (L15) that produces cDNA-derived P400/InsP3-R. In membranes, this protein displays high affinity, specificity, and capacity for InsP3, as does the cerebellar P400/InsP3-R. InsP3 can also induce greater 45Ca2+ release from the membrane vesicles of L15 cells than from those of control L cells. These results provide direct evidence that the cDNA-derived P400/InsP3-R protein is actually involved in physiological Ca2+ mobilization, through binding to InsP3 molecules in the same manner as the cerebellar P400/InsP3-R.
Miyawaki
A
A
Division of Behavior and Neurobiology, National Institute for Basic Biology, Okazaki, Japan.
Furuichi
T
T
Maeda
N
N
Mikoshiba
K
K
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels; D002460:Cell Line; D002531:Cerebellum / Q000378:metabolism*; D004247:DNA / Q000502:physiology; D005347:Fibroblasts / Q000378:metabolism*; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism; D053496:Inositol 1,4,5-Trisphosphate Receptors; D007295:Inositol Phosphates / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D018160:Receptors, Cytoplasmic and Nuclear
D015220:Calcium Channels; D053496:Inositol 1,4,5-Trisphosphate Receptors; D007295:Inositol Phosphates; D011956:Receptors, Cell Surface; D018160:Receptors, Cytoplasmic and Nuclear; D015544:Inositol 1,4,5-Trisphosphate; D004247:DNA; D002118:Calcium