TY - JOUR
T1 - Junctate is a key element in calcium entry induced by activation of InsP3 receptors and/or calcium store depletion
AU - Treves, Susan
AU - Franzini-Armstrong, Clara
AU - Moccagatta, Luca
AU - Arnoult, Christophe
AU - Grasso, Cristiano
AU - Schrum, Adam
AU - Ducreux, Sylvie
AU - Zhu, Michael X.
AU - Mikoshiba, Katsuhiko
AU - Girard, Thierry
AU - Smida-Rezgui, Sophia
AU - Ronjat, Michel
AU - Zorzato, Francesco
PY - 2004/8/16
Y1 - 2004/8/16
N2 - In many cell types agonist-receptor activation leads to a rapid and transient release of Ca2+ from intracellular stores via activation of inositol 1,4,5 trisphosphate (InsP3) receptors (InsP3Rs). Stimulated cells activate store- or receptor-operated calcium channels localized in the plasma membrane, allowing entry of extracellular calcium into the cytoplasm, and thus replenishment of intracellular calcium stores. Calcium entry must be finely regulated in order to prevent an excessive intracellular calcium increase. Junctate, an integral calcium binding protein of endo(sarco)plasmic reticulum membrane, (a) induces and/or stabilizes peripheral couplings between the ER and the plasma membrane, and (b) forms a supramolecular complex with the InsP3R and the canonical transient receptor potential protein (TRPC) 3 calcium entry channel. The full-length protein modulates both agonist-induced and store depletion-induced calcium entry, whereas its NH2 terminus affects receptor-activated calcium entry. RNA interference to deplete cells of endogenous junctate, knocked down both agonist-activated calcium release from intracellular stores and calcium entry via TRPC3. These results demonstrate that junctate is a new protein involved in calcium homeostasis in eukaryotic cells.
AB - In many cell types agonist-receptor activation leads to a rapid and transient release of Ca2+ from intracellular stores via activation of inositol 1,4,5 trisphosphate (InsP3) receptors (InsP3Rs). Stimulated cells activate store- or receptor-operated calcium channels localized in the plasma membrane, allowing entry of extracellular calcium into the cytoplasm, and thus replenishment of intracellular calcium stores. Calcium entry must be finely regulated in order to prevent an excessive intracellular calcium increase. Junctate, an integral calcium binding protein of endo(sarco)plasmic reticulum membrane, (a) induces and/or stabilizes peripheral couplings between the ER and the plasma membrane, and (b) forms a supramolecular complex with the InsP3R and the canonical transient receptor potential protein (TRPC) 3 calcium entry channel. The full-length protein modulates both agonist-induced and store depletion-induced calcium entry, whereas its NH2 terminus affects receptor-activated calcium entry. RNA interference to deplete cells of endogenous junctate, knocked down both agonist-activated calcium release from intracellular stores and calcium entry via TRPC3. These results demonstrate that junctate is a new protein involved in calcium homeostasis in eukaryotic cells.
KW - Calcium binding protein
KW - Calcium entry channel
KW - Calcium homeostasis
KW - ER
KW - IPR
UR - http://www.scopus.com/inward/record.url?scp=4143050320&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=4143050320&partnerID=8YFLogxK
U2 - 10.1083/jcb.200404079
DO - 10.1083/jcb.200404079
M3 - Article
C2 - 15302852
AN - SCOPUS:4143050320
SN - 0021-9525
VL - 166
SP - 537
EP - 548
JO - Journal of Cell Biology
JF - Journal of Cell Biology
IS - 4
ER -