TY - JOUR
T1 - The role of canonical transient receptor potential 7 in B-cell receptor-activated channels
AU - Lievremont, Jean Philippe
AU - Numaga, Takuro
AU - Vazquez, Guillermo
AU - Lemonnier, Loïc
AU - Hara, Yuji
AU - Mori, Emiko
AU - Trebak, Mohamed
AU - Moss, Stephen E.
AU - Bird, Gary S.
AU - Mori, Yasuo
AU - Putney, James W.
PY - 2005/10/21
Y1 - 2005/10/21
N2 - Phospholipase C signaling stimulates Ca2+ entry across the plasma membrane through multiple mechanisms. Ca2+ store depletion stimulates store-operated Ca2+-selective channels, or alternatively, other phospholipase C-dependent events activate Ca2+-permeable non-selective cation channels. Transient receptor potential 7 (TRPC7) is a non-selective cation channel that can be activated by both mechanisms when ectopically expressed, but the regulation of native TRPC7 channels is not known. We knocked out TRPC7 in DT40 B-cells, which expresses both forms of Ca 2+ entry. No difference in the store-operated current I crac was detected between TRPC7-/- and wild-type cells. Wild-type cells demonstrated non-store-operated cation entry and currents in response to activation of the B-cell receptor or protease-activated receptor 2, intracellular dialysis with GTPγS, or application of the synthetic diacylglycerol oleyl-acetyl-glycerol. These responses were absent in TRPC7 -/- cells but could be restored by transfection with human TRPC7. In conclusion, in B-lymphocytes, TRPC7 appeared to participate in the formation of ion channels that could be activated by phospholipase C-linked receptors. This represents the first demonstration of a physiological function for endogenous TRPC7 channels.
AB - Phospholipase C signaling stimulates Ca2+ entry across the plasma membrane through multiple mechanisms. Ca2+ store depletion stimulates store-operated Ca2+-selective channels, or alternatively, other phospholipase C-dependent events activate Ca2+-permeable non-selective cation channels. Transient receptor potential 7 (TRPC7) is a non-selective cation channel that can be activated by both mechanisms when ectopically expressed, but the regulation of native TRPC7 channels is not known. We knocked out TRPC7 in DT40 B-cells, which expresses both forms of Ca 2+ entry. No difference in the store-operated current I crac was detected between TRPC7-/- and wild-type cells. Wild-type cells demonstrated non-store-operated cation entry and currents in response to activation of the B-cell receptor or protease-activated receptor 2, intracellular dialysis with GTPγS, or application of the synthetic diacylglycerol oleyl-acetyl-glycerol. These responses were absent in TRPC7 -/- cells but could be restored by transfection with human TRPC7. In conclusion, in B-lymphocytes, TRPC7 appeared to participate in the formation of ion channels that could be activated by phospholipase C-linked receptors. This represents the first demonstration of a physiological function for endogenous TRPC7 channels.
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U2 - 10.1074/jbc.M507606200
DO - 10.1074/jbc.M507606200
M3 - Article
C2 - 16123040
AN - SCOPUS:27444447986
VL - 280
SP - 35346
EP - 35351
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 42
ER -