3oxq

Crystal Structure of Ca2+/CaM-CaV1.2 pre-IQ/IQ domain complex

spinqualitylabelsall models 3oxq, resolution 2.55Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3oxq is a 6 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.55Å Ligands: CA Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Disease CALM1_HUMAN The disease is caused by mutations affecting the gene represented in this entry. Mutations in CALM1 are the cause of CPVT4. The disease is caused by mutations affecting the gene represented in this entry. Mutations in CALM1 are the cause of LQT14. Function CALM1_HUMAN Calmodulin mediates the control of a large number of enzymes, ion channels, aquaporins and other proteins through calcium-binding. Among the enzymes to be stimulated by the calmodulin-calcium complex are a number of protein kinases and phosphatases. Together with CCP110 and centrin, is involved in a genetic pathway that regulates the centrosome cycle and progression through cytokinesis (PubMed:16760425). Mediates calcium-dependent inactivation of CACNA1C (PubMed:26969752). Positively regulates calcium-activated potassium channel activity of KCNN2 (PubMed:27165696). Publication Abstract from PubMed Interactions between voltage-gated calcium channels (Ca(V)s) and calmodulin (CaM) modulate Ca(V) function. In this study, we report the structure of a Ca(2+)/CaM Ca(V)1.2 C-terminal tail complex that contains two PreIQ helices bridged by two Ca(2+)/CaMs and two Ca(2+)/CaM-IQ domain complexes. Sedimentation equilibrium experiments establish that the complex has a 2:1 Ca(2+)/CaM:C-terminal tail stoichiometry and does not form higher order assemblies. Moreover, subunit-counting experiments demonstrate that in live cell membranes Ca(V)1.2s are monomers. Thus, contrary to previous proposals, the crystallographic dimer lacks physiological relevance. Isothermal titration calorimetry and biochemical experiments show that the two Ca(2+)/CaMs in the complex have different properties. Ca(2+)/CaM bound to the PreIQ C-region is labile, whereas Ca(2+)/CaM bound to the IQ domain is not. Furthermore, neither of lobes of apo-CaM interacts strongly with the PreIQ domain. Electrophysiological studies indicate that the PreIQ C-region has a role in calcium-dependent facilitation. Together, the data show that two Ca(2+)/CaMs can bind the Ca(V)1.2 tail simultaneously and indicate a functional role for Ca(2+)/CaM at the C-region site. Multiple C-terminal tail Ca(2+)/CaMs regulate Ca(V)1.2 function but do not mediate channel dimerization.,Kim EY, Rumpf CH, Van Petegem F, Arant RJ, Findeisen F, Cooley ES, Isacoff EY, Minor DL Jr EMBO J. 2010 Oct 15. PMID:20953164 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Calmodulin 3D structures Ion channels 3D structures

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