Sandbox Reserved 820: Difference between revisions
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The binding site of CASQ2 to Ryanodin Receptor (RyR) is unknow.<ref name="Regulation of Ryanodine Receptors by Calsequestrin: Effect of High Luminal Ca2+ and Phosphorylation (Beard et Al., 2005)">http://www.ncbi.nlm.nih.gov/pubmed/15731387</ref> | The binding site of CASQ2 to Ryanodin Receptor (RyR) is unknow.<ref name="Regulation of Ryanodine Receptors by Calsequestrin: Effect of High Luminal Ca2+ and Phosphorylation (Beard et Al., 2005)">http://www.ncbi.nlm.nih.gov/pubmed/15731387</ref> | ||
=== Consequences | === Consequences of CASQ2 binding === | ||
When CASQ2 binds to triadin and junctin, it induces the inhibition of RyR and then the inhibition of calcium release in the cytoplasm. On the contrary, when CASQ2 unbinds triadin and junctin, it induces the activation of Ryr and an efflux of Ca<sup>2+</sup> from the SR to the cytoplasm.<ref name="Calsequestrin and the calcium release channel of skeletal and cardiac muscle (Beard et Al., 2004)">http://www.ncbi.nlm.nih.gov/pubmed/15050380</ref> CASQ2 is free when the concentration of Ca<sup>2+</sup> is higher than 1 mM in the SR lumen.<ref name="Regulation of Ryanodine Receptors by Calsequestrin: Effect of High Luminal Ca2+ and Phosphorylation (Beard et Al., 2005)">http://www.ncbi.nlm.nih.gov/pubmed/15731387</ref> | When CASQ2 binds to triadin and junctin, it induces the inhibition of RyR and then the inhibition of calcium release in the cytoplasm. On the contrary, when CASQ2 unbinds triadin and junctin, it induces the activation of Ryr and an efflux of Ca<sup>2+</sup> from the SR to the cytoplasm.<ref name="Calsequestrin and the calcium release channel of skeletal and cardiac muscle (Beard et Al., 2004)">http://www.ncbi.nlm.nih.gov/pubmed/15050380</ref> CASQ2 is free when the concentration of Ca<sup>2+</sup> is higher than 1 mM in the SR lumen.<ref name="Regulation of Ryanodine Receptors by Calsequestrin: Effect of High Luminal Ca2+ and Phosphorylation (Beard et Al., 2005)">http://www.ncbi.nlm.nih.gov/pubmed/15731387</ref> | ||
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== Regulation of CASQ2 == | == Regulation of CASQ2 == | ||
CASQ2 can be phosphorylated by three different kinases: casein kinase I (CK I), casein | CASQ2 can be phosphorylated by three different kinases: casein kinase I (CK I), casein kinase II (CK II) and ε protein kinase C1 (εPKC1).<ref name="Calsequestrin and the calcium release channel of skeletal and cardiac muscle (Beard et Al., 2004)">http://www.ncbi.nlm.nih.gov/pubmed/15050380</ref> CK II is located in the SR and is able to phosphorylate Ser 378, Ser 382 and Ser 386. These residues are on the C-terminal domain.<ref name="Calsequestrin and the calcium release channel of skeletal and cardiac muscle (Beard et Al., 2004)">http://www.ncbi.nlm.nih.gov/pubmed/15050380</ref> The consensus sequence recognized by CK II is Ser/Thr-X-X-Asp/Glu.<ref name="Calsequestrin and the calcium release channel of skeletal and cardiac muscle (Beard et Al., 2004)">http://www.ncbi.nlm.nih.gov/pubmed/15050380</ref> The phosphorylation is more likely if there are acidic residues after this consensur sequence.<ref name="Calsequestrin and the calcium release channel of skeletal and cardiac muscle (Beard et Al., 2004)">http://www.ncbi.nlm.nih.gov/pubmed/15050380</ref> | ||
"The phosphorylation and de-phosphorylation of CASQ2 my provide an off/on switch for CASQ2 to regulate Ca2+" <!-- A reformuler, mais bon...! --> But there is not any prove yet.<ref name="Calsequestrin and the calcium release channel of skeletal and cardiac muscle (Beard et Al., 2004)">http://www.ncbi.nlm.nih.gov/pubmed/15050380</ref> | "The phosphorylation and de-phosphorylation of CASQ2 my provide an off/on switch for CASQ2 to regulate Ca2+" <!-- A reformuler, mais bon...! --> But there is not any prove yet.<ref name="Calsequestrin and the calcium release channel of skeletal and cardiac muscle (Beard et Al., 2004)">http://www.ncbi.nlm.nih.gov/pubmed/15050380</ref> | ||