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| | <StructureSection load='6ale' size='340' side='right'caption='[[6ale]], [[Resolution|resolution]] 2.50Å' scene=''> | | <StructureSection load='6ale' size='340' side='right'caption='[[6ale]], [[Resolution|resolution]] 2.50Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[6ale]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Buffalo_rat Buffalo rat] and [http://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6ALE OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6ALE FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[6ale]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] and [https://en.wikipedia.org/wiki/Rattus_norvegicus Rattus norvegicus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6ALE OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6ALE FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=1KP:(3E)-6,7-DICHLORO-3-(HYDROXYIMINO)-1,3-DIHYDRO-2H-INDOL-2-ONE'>1KP</scene>, <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.5Å</td></tr> |
| - | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">KCNN2 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 HUMAN]), Calm2, Cam2, Camb, CaMII ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=10116 Buffalo rat])</td></tr>
| + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=1KP:(3E)-6,7-DICHLORO-3-(HYDROXYIMINO)-1,3-DIHYDRO-2H-INDOL-2-ONE'>1KP</scene>, <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr> |
| - | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6ale FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6ale OCA], [http://pdbe.org/6ale PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=6ale RCSB], [http://www.ebi.ac.uk/pdbsum/6ale PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=6ale ProSAT]</span></td></tr> | + | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=6ale FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6ale OCA], [https://pdbe.org/6ale PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6ale RCSB], [https://www.ebi.ac.uk/pdbsum/6ale PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6ale ProSAT]</span></td></tr> |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/KCNN2_HUMAN KCNN2_HUMAN]] Forms a voltage-independent potassium channel activated by intracellular calcium. Activation is followed by membrane hyperpolarization. Thought to regulate neuronal excitability by contributing to the slow component of synaptic afterhyperpolarization. The channel is blocked by apamin. [[http://www.uniprot.org/uniprot/CALM2_RAT CALM2_RAT]] 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. Mediates calcium-dependent inactivation of CACNA1C. Positively regulates calcium-activated potassium channel activity of KCNN2.[UniProtKB:P62158] | + | [https://www.uniprot.org/uniprot/KCNN2_HUMAN KCNN2_HUMAN] Forms a voltage-independent potassium channel activated by intracellular calcium. Activation is followed by membrane hyperpolarization. Thought to regulate neuronal excitability by contributing to the slow component of synaptic afterhyperpolarization. The channel is blocked by apamin. |
| - | <div style="background-color:#fffaf0;">
| + | |
| - | == Publication Abstract from PubMed ==
| + | |
| - | Small-conductance Ca(2+)-activated K(+) (SK) channels mediate medium afterhyperpolarization in the neurons and play a key role in the regulation of neuronal excitability. SK channels are potential drug targets for ataxia and Amyotrophic Lateral Sclerosis (ALS). SK channels are activated exclusively by the Ca(2+)-bound calmodulin. Previously, we identified an intrinsically disordered fragment that is essential for the mechanical coupling between Ca(2+)/calmodulin binding and channel opening. Here, we report that substitution of a valine to phenylalanine (V407F) in the intrinsically disordered fragment caused a ~6 fold increase in the Ca(2+) sensitivity of SK2-a channels. This substitution resulted in a novel interaction between the ectopic phenylalanine and M411, which stabilized PIP2-interacting residue K405, and subsequently enhanced Ca(2+) sensitivity. Also, equivalent valine to phenylalanine substitutions in SK1 or SK3 channels conferred Ca(2+) hypersensitivity. An equivalent phenylalanine substitution in the Caenorhabditis elegans (C. elegans) SK2 ortholog kcnl-2 partially rescued locomotion defects in an existing C. elegans ALS model, in which human SOD1G85R is expressed at high levels in neurons, confirming that this phenylalanine substitution impacts channel function in vivo. This work for the first time provides a critical reagent for future studies: an SK channel that is hypersensitive to Ca(2+) with increased activity in vivo.
| + | |
| - | | + | |
| - | A V-to-F substitution in SK2 channels causes Ca(2+) hypersensitivity and improves locomotion in a C. elegans ALS model.,Nam YW, Baskoylu SN, Gazgalis D, Orfali R, Cui M, Hart AC, Zhang M Sci Rep. 2018 Jul 16;8(1):10749. doi: 10.1038/s41598-018-28783-2. PMID:30013223<ref>PMID:30013223</ref>
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| - | | + | |
| - | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br>
| + | |
| - | </div>
| + | |
| - | <div class="pdbe-citations 6ale" style="background-color:#fffaf0;"></div>
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| | | | |
| | ==See Also== | | ==See Also== |
| | *[[Calmodulin 3D structures|Calmodulin 3D structures]] | | *[[Calmodulin 3D structures|Calmodulin 3D structures]] |
| | *[[Potassium channel 3D structures|Potassium channel 3D structures]] | | *[[Potassium channel 3D structures|Potassium channel 3D structures]] |
| - | == References == | |
| - | <references/> | |
| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Buffalo rat]] | + | [[Category: Homo sapiens]] |
| - | [[Category: Human]]
| + | |
| | [[Category: Large Structures]] | | [[Category: Large Structures]] |
| - | [[Category: Nam, Y W]] | + | [[Category: Rattus norvegicus]] |
| - | [[Category: Zhang, M]] | + | [[Category: Nam YW]] |
| - | [[Category: Calcium binding protein]] | + | [[Category: Zhang M]] |
| - | [[Category: Metal transport]]
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