2be6: Difference between revisions
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==2.0 A crystal structure of the CaV1.2 IQ domain-Ca/CaM complex== | |||
===2. | <StructureSection load='2be6' size='340' side='right' caption='[[2be6]], [[Resolution|resolution]] 2.00Å' scene=''> | ||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[2be6]] is a 6 chain structure with sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2BE6 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2BE6 FirstGlance]. <br> | |||
</td></tr><tr><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=NI:NICKEL+(II)+ION'>NI</scene><br> | |||
<tr><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">CALM2 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 Homo sapiens]), CACNA1C, CACH2, CACN2, CACNL1A1, CCHL1A1 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 Homo sapiens])</td></tr> | |||
<tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2be6 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2be6 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=2be6 RCSB], [http://www.ebi.ac.uk/pdbsum/2be6 PDBsum]</span></td></tr> | |||
<table> | |||
== Disease == | |||
[[http://www.uniprot.org/uniprot/CAC1C_HUMAN CAC1C_HUMAN]] Defects in CACNA1C are the cause of Timothy syndrome (TS) [MIM:[http://omim.org/entry/601005 601005]]. TS is a disorder characterized by multiorgan dysfunction including lethal arrhythmias, webbing of fingers and toes, congenital heart disease, immune deficiency, intermittent hypoglycemia, cognitive abnormalities and autism.<ref>PMID:15454078</ref> <ref>PMID:15863612</ref> Defects in CACNA1C are the cause of Brugada syndrome type 3 (BRGDA3) [MIM:[http://omim.org/entry/611875 611875]]. A heart disease characterized by the association of Brugada syndrome with shortened QT intervals. Brugada syndrome is a tachyarrhythmia characterized by right bundle branch block and ST segment elevation on an electrocardiogram (ECG). It can cause the ventricles to beat so fast that the blood is prevented from circulating efficiently in the body. When this situation occurs (called ventricular fibrillation), the individual will faint and may die in a few minutes if the heart is not reset.<ref>PMID:17224476</ref> | |||
== Function == | |||
[[http://www.uniprot.org/uniprot/CAC1C_HUMAN CAC1C_HUMAN]] Voltage-sensitive calcium channels (VSCC) mediate the entry of calcium ions into excitable cells and are also involved in a variety of calcium-dependent processes, including muscle contraction, hormone or neurotransmitter release, gene expression, cell motility, cell division and cell death. The isoform alpha-1C gives rise to L-type calcium currents. Long-lasting (L-type) calcium channels belong to the 'high-voltage activated' (HVA) group. They are blocked by dihydropyridines (DHP), phenylalkylamines, benzothiazepines, and by omega-agatoxin-IIIA (omega-Aga-IIIA). They are however insensitive to omega-conotoxin-GVIA (omega-CTx-GVIA) and omega-agatoxin-IVA (omega-Aga-IVA). Calcium channels containing the alpha-1C subunit play an important role in excitation-contraction coupling in the heart. The various isoforms display marked differences in the sensitivity to DHP compounds. Binding of calmodulin or CABP1 at the same regulatory sites results in an opposit effects on the channel function.<ref>PMID:8392192</ref> <ref>PMID:7737988</ref> <ref>PMID:9013606</ref> <ref>PMID:9607315</ref> <ref>PMID:12176756</ref> <ref>PMID:17071743</ref> | |||
== Evolutionary Conservation == | |||
[[Image:Consurf_key_small.gif|200px|right]] | |||
Check<jmol> | |||
<jmolCheckbox> | |||
<scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/be/2be6_consurf.spt"</scriptWhenChecked> | |||
<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | |||
<text>to colour the structure by Evolutionary Conservation</text> | |||
</jmolCheckbox> | |||
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/chain_selection.php?pdb_ID=2ata ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Changes in activity-dependent calcium flux through voltage-gated calcium channels (Ca(V)s) drive two self-regulatory calcium-dependent feedback processes that require interaction between Ca(2+)/calmodulin (Ca(2+)/CaM) and a Ca(V) channel consensus isoleucine-glutamine (IQ) motif: calcium-dependent inactivation (CDI) and calcium-dependent facilitation (CDF). Here, we report the high-resolution structure of the Ca(2+)/CaM-Ca(V)1.2 IQ domain complex. The IQ domain engages hydrophobic pockets in the N-terminal and C-terminal Ca(2+)/CaM lobes through sets of conserved 'aromatic anchors.' Ca(2+)/N lobe adopts two conformations that suggest inherent conformational plasticity at the Ca(2+)/N lobe-IQ domain interface. Titration calorimetry experiments reveal competition between the lobes for IQ domain sites. Electrophysiological examination of Ca(2+)/N lobe aromatic anchors uncovers their role in Ca(V)1.2 CDF. Together, our data suggest that Ca(V) subtype differences in CDI and CDF are tuned by changes in IQ domain anchoring positions and establish a framework for understanding CaM lobe-specific regulation of Ca(V)s. | |||
Insights into voltage-gated calcium channel regulation from the structure of the CaV1.2 IQ domain-Ca2+/calmodulin complex.,Van Petegem F, Chatelain FC, Minor DL Jr Nat Struct Mol Biol. 2005 Dec;12(12):1108-15. Epub 2005 Nov 20. PMID:16299511<ref>PMID:16299511</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
==See Also== | ==See Also== | ||
*[[Calmodulin|Calmodulin]] | *[[Calmodulin|Calmodulin]] | ||
*[[Ion channels|Ion channels]] | *[[Ion channels|Ion channels]] | ||
== References == | |||
== | <references/> | ||
__TOC__ | |||
</StructureSection> | |||
[[Category: Homo sapiens]] | [[Category: Homo sapiens]] | ||
[[Category: Chatelain, F C.]] | [[Category: Chatelain, F C.]] |
Revision as of 05:47, 30 September 2014
2.0 A crystal structure of the CaV1.2 IQ domain-Ca/CaM complex2.0 A crystal structure of the CaV1.2 IQ domain-Ca/CaM complex
Structural highlights
Disease[CAC1C_HUMAN] Defects in CACNA1C are the cause of Timothy syndrome (TS) [MIM:601005]. TS is a disorder characterized by multiorgan dysfunction including lethal arrhythmias, webbing of fingers and toes, congenital heart disease, immune deficiency, intermittent hypoglycemia, cognitive abnormalities and autism.[1] [2] Defects in CACNA1C are the cause of Brugada syndrome type 3 (BRGDA3) [MIM:611875]. A heart disease characterized by the association of Brugada syndrome with shortened QT intervals. Brugada syndrome is a tachyarrhythmia characterized by right bundle branch block and ST segment elevation on an electrocardiogram (ECG). It can cause the ventricles to beat so fast that the blood is prevented from circulating efficiently in the body. When this situation occurs (called ventricular fibrillation), the individual will faint and may die in a few minutes if the heart is not reset.[3] Function[CAC1C_HUMAN] Voltage-sensitive calcium channels (VSCC) mediate the entry of calcium ions into excitable cells and are also involved in a variety of calcium-dependent processes, including muscle contraction, hormone or neurotransmitter release, gene expression, cell motility, cell division and cell death. The isoform alpha-1C gives rise to L-type calcium currents. Long-lasting (L-type) calcium channels belong to the 'high-voltage activated' (HVA) group. They are blocked by dihydropyridines (DHP), phenylalkylamines, benzothiazepines, and by omega-agatoxin-IIIA (omega-Aga-IIIA). They are however insensitive to omega-conotoxin-GVIA (omega-CTx-GVIA) and omega-agatoxin-IVA (omega-Aga-IVA). Calcium channels containing the alpha-1C subunit play an important role in excitation-contraction coupling in the heart. The various isoforms display marked differences in the sensitivity to DHP compounds. Binding of calmodulin or CABP1 at the same regulatory sites results in an opposit effects on the channel function.[4] [5] [6] [7] [8] [9] Evolutionary Conservation![]() Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedChanges in activity-dependent calcium flux through voltage-gated calcium channels (Ca(V)s) drive two self-regulatory calcium-dependent feedback processes that require interaction between Ca(2+)/calmodulin (Ca(2+)/CaM) and a Ca(V) channel consensus isoleucine-glutamine (IQ) motif: calcium-dependent inactivation (CDI) and calcium-dependent facilitation (CDF). Here, we report the high-resolution structure of the Ca(2+)/CaM-Ca(V)1.2 IQ domain complex. The IQ domain engages hydrophobic pockets in the N-terminal and C-terminal Ca(2+)/CaM lobes through sets of conserved 'aromatic anchors.' Ca(2+)/N lobe adopts two conformations that suggest inherent conformational plasticity at the Ca(2+)/N lobe-IQ domain interface. Titration calorimetry experiments reveal competition between the lobes for IQ domain sites. Electrophysiological examination of Ca(2+)/N lobe aromatic anchors uncovers their role in Ca(V)1.2 CDF. Together, our data suggest that Ca(V) subtype differences in CDI and CDF are tuned by changes in IQ domain anchoring positions and establish a framework for understanding CaM lobe-specific regulation of Ca(V)s. Insights into voltage-gated calcium channel regulation from the structure of the CaV1.2 IQ domain-Ca2+/calmodulin complex.,Van Petegem F, Chatelain FC, Minor DL Jr Nat Struct Mol Biol. 2005 Dec;12(12):1108-15. Epub 2005 Nov 20. PMID:16299511[10] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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