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- | [[Image:2qvk.jpg|left|200px]] | |
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- | <!--
| + | ==The second Ca2+-binding domain of the Na+-Ca2+ exchanger is essential for regulation: crystal structures and mutational analysis== |
- | The line below this paragraph, containing "STRUCTURE_2qvk", creates the "Structure Box" on the page.
| + | <StructureSection load='2qvk' size='340' side='right'caption='[[2qvk]], [[Resolution|resolution]] 1.45Å' scene=''> |
- | You may change the PDB parameter (which sets the PDB file loaded into the applet)
| + | == Structural highlights == |
- | or the SCENE parameter (which sets the initial scene displayed when the page is loaded),
| + | <table><tr><td colspan='2'>[[2qvk]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Canis_lupus_familiaris Canis lupus familiaris]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2QVK OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2QVK FirstGlance]. <br> |
- | or leave the SCENE parameter empty for the default display.
| + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.451Å</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=2qvk FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2qvk OCA], [https://pdbe.org/2qvk PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2qvk RCSB], [https://www.ebi.ac.uk/pdbsum/2qvk PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2qvk ProSAT]</span></td></tr> |
- | {{STRUCTURE_2qvk| PDB=2qvk | SCENE= }}
| + | </table> |
- | | + | == Function == |
- | '''The second Ca2+-binding domain of the Na+-Ca2+ exchanger is essential for regulation: crystal structures and mutational analysis'''
| + | [https://www.uniprot.org/uniprot/NAC1_CANLF NAC1_CANLF] Mediates the exchange of one Ca(2+) ion against three to four Na(+) ions across the cell membrane, and thereby contributes to the regulation of cytoplasmic Ca(2+) levels and Ca(2+)-dependent cellular processes (PubMed:1700476, PubMed:1785844, PubMed:9486131, PubMed:17962412). Contributes to Ca(2+) transport during excitation-contraction coupling in muscle. In a first phase, voltage-gated channels mediate the rapid increase of cytoplasmic Ca(2+) levels due to release of Ca(2+) stores from the endoplasmic reticulum. SLC8A1 mediates the export of Ca(2+) from the cell during the next phase, so that cytoplasmic Ca(2+) levels rapidly return to baseline. Required for normal embryonic heart development and the onset of heart contractions (By similarity).[UniProtKB:P70414]<ref>PMID:1700476</ref> <ref>PMID:1785844</ref> <ref>PMID:17962412</ref> <ref>PMID:19332552</ref> <ref>PMID:9486131</ref> |
- | | + | == Evolutionary Conservation == |
- | | + | [[Image:Consurf_key_small.gif|200px|right]] |
- | ==Overview== | + | Check<jmol> |
- | The Na(+)-Ca(2+) exchanger plays a central role in cardiac contractility by maintaining Ca(2+) homeostasis. Two Ca(2+)-binding domains, CBD1 and CBD2, located in a large intracellular loop, regulate activity of the exchanger. Ca(2+) binding to these regulatory domains activates the transport of Ca(2+) across the plasma membrane. Previously, we solved the structure of CBD1, revealing four Ca(2+) ions arranged in a tight planar cluster. Here, we present structures of CBD2 in the Ca(2+)-bound (1.7-A resolution) and -free (1.4-A resolution) conformations. Like CBD1, CBD2 has a classical Ig fold but coordinates only two Ca(2+) ions in primary and secondary Ca(2+) sites. In the absence of Ca(2+), Lys(585) stabilizes the structure by coordinating two acidic residues (Asp(552) and Glu(648)), one from each of the Ca(2+)-binding sites, and prevents a substantial protein unfolding. We have mutated all of the acidic residues that coordinate the Ca(2+) ions and have examined the effects of these mutations on regulation of exchange activity. Three mutations (E516L, D578V, and E648L) at the primary Ca(2+) site completely remove Ca(2+) regulation, placing the exchanger into a constitutively active state. These are the first data defining the role of CBD2 as a regulatory domain in the Na(+)-Ca(2+) exchanger.
| + | <jmolCheckbox> |
- | | + | <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/qv/2qvk_consurf.spt"</scriptWhenChecked> |
- | ==About this Structure== | + | <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> |
- | 2QVK is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Canis_lupus_familiaris Canis lupus familiaris]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2QVK OCA].
| + | <text>to colour the structure by Evolutionary Conservation</text> |
- | | + | </jmolCheckbox> |
- | ==Reference== | + | </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/main_output.php?pdb_ID=2qvk ConSurf]. |
- | The second Ca2+-binding domain of the Na+ Ca2+ exchanger is essential for regulation: crystal structures and mutational analysis., Besserer GM, Ottolia M, Nicoll DA, Chaptal V, Cascio D, Philipson KD, Abramson J, Proc Natl Acad Sci U S A. 2007 Nov 20;104(47):18467-72. Epub 2007 Oct 25. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/17962412 17962412]
| + | <div style="clear:both"></div> |
| + | == References == |
| + | <references/> |
| + | __TOC__ |
| + | </StructureSection> |
| [[Category: Canis lupus familiaris]] | | [[Category: Canis lupus familiaris]] |
- | [[Category: Single protein]] | + | [[Category: Large Structures]] |
- | [[Category: Abramson, J.]] | + | [[Category: Abramson J]] |
- | [[Category: Besserer, G Mercado.]]
| + | [[Category: Cascio D]] |
- | [[Category: Cascio, D.]] | + | [[Category: Chaptal V]] |
- | [[Category: Chaptal, V.]] | + | [[Category: Mercado Besserer G]] |
- | [[Category: Calcium binding domain]] | + | |
- | [[Category: Cbd2]]
| + | |
- | [[Category: Metal binding protein]]
| + | |
- | [[Category: Sodium calcium exchanger]]
| + | |
- | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun May 4 15:45:47 2008''
| + | |
| Structural highlights
Function
NAC1_CANLF Mediates the exchange of one Ca(2+) ion against three to four Na(+) ions across the cell membrane, and thereby contributes to the regulation of cytoplasmic Ca(2+) levels and Ca(2+)-dependent cellular processes (PubMed:1700476, PubMed:1785844, PubMed:9486131, PubMed:17962412). Contributes to Ca(2+) transport during excitation-contraction coupling in muscle. In a first phase, voltage-gated channels mediate the rapid increase of cytoplasmic Ca(2+) levels due to release of Ca(2+) stores from the endoplasmic reticulum. SLC8A1 mediates the export of Ca(2+) from the cell during the next phase, so that cytoplasmic Ca(2+) levels rapidly return to baseline. Required for normal embryonic heart development and the onset of heart contractions (By similarity).[UniProtKB:P70414][1] [2] [3] [4] [5]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
References
- ↑ Nicoll DA, Longoni S, Philipson KD. Molecular cloning and functional expression of the cardiac sarcolemmal Na(+)-Ca2+ exchanger. Science. 1990 Oct 26;250(4980):562-5. PMID:1700476
- ↑ Nicoll DA, Philipson KD. Molecular studies of the cardiac sarcolemmal sodium-calcium exchanger. Ann N Y Acad Sci. 1991;639:181-8. PMID:1785844
- ↑ Besserer GM, Ottolia M, Nicoll DA, Chaptal V, Cascio D, Philipson KD, Abramson J. The second Ca2+-binding domain of the Na+ Ca2+ exchanger is essential for regulation: crystal structures and mutational analysis. Proc Natl Acad Sci U S A. 2007 Nov 20;104(47):18467-72. Epub 2007 Oct 25. PMID:17962412
- ↑ Chaptal V, Ottolia M, Mercado-Besserer G, Nicoll DA, Philipson KD, Abramson J. Structure and functional analysis of a Ca2+ sensor mutant of the Na+/Ca2+ exchanger. J Biol Chem. 2009 May 29;284(22):14688-92. Epub 2009 Mar 30. PMID:19332552 doi:10.1074/jbc.C900037200
- ↑ Linck B, Qiu Z, He Z, Tong Q, Hilgemann DW, Philipson KD. Functional comparison of the three isoforms of the Na+/Ca2+ exchanger (NCX1, NCX2, NCX3). Am J Physiol. 1998 Feb;274(2 Pt 1):C415-23. PMID:9486131
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