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| | <StructureSection load='4aqr' size='340' side='right'caption='[[4aqr]], [[Resolution|resolution]] 1.95Å' scene=''> | | <StructureSection load='4aqr' size='340' side='right'caption='[[4aqr]], [[Resolution|resolution]] 1.95Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[4aqr]] is a 3 chain structure with sequence from [http://en.wikipedia.org/wiki/Arath Arath]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4AQR OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4AQR FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[4aqr]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Arath Arath]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4AQR OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4AQR 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></td></tr> | + | </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></td></tr> |
| - | <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Calcium-transporting_ATPase Calcium-transporting ATPase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.6.3.8 3.6.3.8] </span></td></tr> | + | <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[https://en.wikipedia.org/wiki/Calcium-transporting_ATPase Calcium-transporting ATPase], with EC number [https://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.6.3.8 3.6.3.8] </span></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=4aqr FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4aqr OCA], [http://pdbe.org/4aqr PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=4aqr RCSB], [http://www.ebi.ac.uk/pdbsum/4aqr PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=4aqr 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=4aqr FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4aqr OCA], [https://pdbe.org/4aqr PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4aqr RCSB], [https://www.ebi.ac.uk/pdbsum/4aqr PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4aqr ProSAT]</span></td></tr> |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/CALM7_ARATH CALM7_ARATH]] Calmodulin mediates the control of a large number of enzymes, ion channels and other proteins by Ca(2+). Among the enzymes to be stimulated by the calmodulin-Ca(2+) complex are a number of protein kinases and phosphatases. Activates MPK8 in vitro.<ref>PMID:21419340</ref> [[http://www.uniprot.org/uniprot/ACA8_ARATH ACA8_ARATH]] This magnesium-dependent enzyme catalyzes the hydrolysis of ATP coupled with the translocation of calcium from the cytosol out of the cell. | + | [[https://www.uniprot.org/uniprot/CALM7_ARATH CALM7_ARATH]] Calmodulin mediates the control of a large number of enzymes, ion channels and other proteins by Ca(2+). Among the enzymes to be stimulated by the calmodulin-Ca(2+) complex are a number of protein kinases and phosphatases. Activates MPK8 in vitro.<ref>PMID:21419340</ref> [[https://www.uniprot.org/uniprot/ACA8_ARATH ACA8_ARATH]] This magnesium-dependent enzyme catalyzes the hydrolysis of ATP coupled with the translocation of calcium from the cytosol out of the cell. |
| | <div style="background-color:#fffaf0;"> | | <div style="background-color:#fffaf0;"> |
| | == Publication Abstract from PubMed == | | == Publication Abstract from PubMed == |
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| | | | |
| | ==See Also== | | ==See Also== |
| - | *[[Calmodulin|Calmodulin]] | + | *[[Calmodulin 3D structures|Calmodulin 3D structures]] |
| | == References == | | == References == |
| | <references/> | | <references/> |
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| | [[Category: Arath]] | | [[Category: Arath]] |
| | [[Category: Calcium-transporting ATPase]] | | [[Category: Calcium-transporting ATPase]] |
| | + | [[Category: Large Structures]] |
| | [[Category: Andreeva, A]] | | [[Category: Andreeva, A]] |
| | [[Category: Hein, K L]] | | [[Category: Hein, K L]] |
| Structural highlights
Function
[CALM7_ARATH] Calmodulin mediates the control of a large number of enzymes, ion channels and other proteins by Ca(2+). Among the enzymes to be stimulated by the calmodulin-Ca(2+) complex are a number of protein kinases and phosphatases. Activates MPK8 in vitro.[1] [ACA8_ARATH] This magnesium-dependent enzyme catalyzes the hydrolysis of ATP coupled with the translocation of calcium from the cytosol out of the cell.
Publication Abstract from PubMed
Calcium ions (Ca(2+)) have an important role as secondary messengers in numerous signal transduction processes, and cells invest much energy in controlling and maintaining a steep gradient between intracellular ( approximately 0.1-micromolar) and extracellular ( approximately 2-millimolar) Ca(2+) concentrations. Calmodulin-stimulated calcium pumps, which include the plasma-membrane Ca(2+)-ATPases (PMCAs), are key regulators of intracellular Ca(2+) in eukaryotes. They contain a unique amino- or carboxy-terminal regulatory domain responsible for autoinhibition, and binding of calcium-loaded calmodulin to this domain releases autoinhibition and activates the pump. However, the structural basis for the activation mechanism is unknown and a key remaining question is how calmodulin-mediated PMCA regulation can cover both basal Ca(2+) levels in the nanomolar range as well as micromolar-range Ca(2+) transients generated by cell stimulation. Here we present an integrated study combining the determination of the high-resolution crystal structure of a PMCA regulatory-domain/calmodulin complex with in vivo characterization and biochemical, biophysical and bioinformatics data that provide mechanistic insights into a two-step PMCA activation mechanism mediated by calcium-loaded calmodulin. The structure shows the entire PMCA regulatory domain and reveals an unexpected 2:1 stoichiometry with two calcium-loaded calmodulin molecules binding to different sites on a long helix. A multifaceted characterization of the role of both sites leads to a general structural model for calmodulin-mediated regulation of PMCAs that allows stringent, highly responsive control of intracellular calcium in eukaryotes, making it possible to maintain a stable, basal level at a threshold Ca(2+) concentration, where steep activation occurs.
A bimodular mechanism of calcium control in eukaryotes.,Tidow H, Poulsen LR, Andreeva A, Knudsen M, Hein KL, Wiuf C, Palmgren MG, Nissen P Nature. 2012 Oct 21. doi: 10.1038/nature11539. PMID:23086147[2]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Takahashi F, Mizoguchi T, Yoshida R, Ichimura K, Shinozaki K. Calmodulin-dependent activation of MAP kinase for ROS homeostasis in Arabidopsis. Mol Cell. 2011 Mar 18;41(6):649-60. doi: 10.1016/j.molcel.2011.02.029. PMID:21419340 doi:http://dx.doi.org/10.1016/j.molcel.2011.02.029
- ↑ Tidow H, Poulsen LR, Andreeva A, Knudsen M, Hein KL, Wiuf C, Palmgren MG, Nissen P. A bimodular mechanism of calcium control in eukaryotes. Nature. 2012 Oct 21. doi: 10.1038/nature11539. PMID:23086147 doi:http://dx.doi.org/10.1038/nature11539
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