4qnh: Difference between revisions

No edit summary
No edit summary
 
(2 intermediate revisions by the same user not shown)
Line 1: Line 1:


==Calcium-calmodulin (T79D) complexed with the calmodulin binding domain from a small conductance potassium channel SK2-a==
==Calcium-calmodulin (T79D) complexed with the calmodulin binding domain from a small conductance potassium channel SK2-a==
<StructureSection load='4qnh' size='340' side='right' caption='[[4qnh]], [[Resolution|resolution]] 2.02&Aring;' scene=''>
<StructureSection load='4qnh' size='340' side='right'caption='[[4qnh]], [[Resolution|resolution]] 2.02&Aring;' scene=''>
== Structural highlights ==
== Structural highlights ==
<table><tr><td colspan='2'>[[4qnh]] is a 2 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4QNH OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4QNH FirstGlance]. <br>
<table><tr><td colspan='2'>[[4qnh]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Rattus_norvegicus Rattus norvegicus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4QNH OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4QNH FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</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]] 2.02&#8491;</td></tr>
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[4j9y|4j9y]]</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</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=4qnh FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4qnh OCA], [http://pdbe.org/4qnh PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=4qnh RCSB], [http://www.ebi.ac.uk/pdbsum/4qnh PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=4qnh 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=4qnh FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4qnh OCA], [https://pdbe.org/4qnh PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4qnh RCSB], [https://www.ebi.ac.uk/pdbsum/4qnh PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4qnh ProSAT]</span></td></tr>
</table>
</table>
== Function ==
== Function ==
[[http://www.uniprot.org/uniprot/KCNN2_RAT KCNN2_RAT]] 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.  
[https://www.uniprot.org/uniprot/KCNN2_RAT KCNN2_RAT] 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 ==
Phosphatidylinositol bisphosphate (PIP2) regulates the activities of many membrane proteins, including ion channels, through direct interactions. However, the affinity of PIP2 is so high for some channel proteins that its physiological role as a modulator has been questioned. Here we show that PIP2 is a key cofactor for activation of small conductance Ca2+-activated potassium channels (SKs) by Ca(2+)-bound calmodulin (CaM). Removal of the endogenous PIP2 inhibits SKs. The PIP2-binding site resides at the interface of CaM and the SK C terminus. We further demonstrate that the affinity of PIP2 for its target proteins can be regulated by cellular signaling. Phosphorylation of CaM T79, located adjacent to the PIP2-binding site, by casein kinase 2 reduces the affinity of PIP2 for the CaM-SK channel complex by altering the dynamic interactions among amino acid residues surrounding the PIP2-binding site. This effect of CaM phosphorylation promotes greater channel inhibition by G protein-mediated hydrolysis of PIP2.
 
Selective phosphorylation modulates the PIP2 sensitivity of the CaM-SK channel complex.,Zhang M, Meng XY, Cui M, Pascal JM, Logothetis DE, Zhang JF Nat Chem Biol. 2014 Sep;10(9):753-9. doi: 10.1038/nchembio.1592. Epub 2014 Aug, 10. PMID:25108821<ref>PMID:25108821</ref>
 
From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4qnh" style="background-color:#fffaf0;"></div>


==See Also==
==See Also==
*[[Calmodulin|Calmodulin]]
*[[Calmodulin 3D structures|Calmodulin 3D structures]]
== References ==
*[[Potassium channel 3D structures|Potassium channel 3D structures]]
<references/>
__TOC__
__TOC__
</StructureSection>
</StructureSection>
[[Category: Logothetis, D E]]
[[Category: Large Structures]]
[[Category: Pascal, J M]]
[[Category: Rattus norvegicus]]
[[Category: Zhang, J F]]
[[Category: Logothetis DE]]
[[Category: Zhang, M]]
[[Category: Pascal JM]]
[[Category: Ion channel]]
[[Category: Zhang JF]]
[[Category: Ion transport-protein binding complex]]
[[Category: Zhang M]]

Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

OCA