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| | ==Crystal structure of native rabbit skeletal calsequestrin== | | ==Crystal structure of native rabbit skeletal calsequestrin== |
| - | <StructureSection load='3trq' size='340' side='right' caption='[[3trq]], [[Resolution|resolution]] 1.76Å' scene=''> | + | <StructureSection load='3trq' size='340' side='right'caption='[[3trq]], [[Resolution|resolution]] 1.76Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[3trq]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Oryctolagus_cuniculus Oryctolagus cuniculus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3TRQ OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3TRQ FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[3trq]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Oryctolagus_cuniculus Oryctolagus cuniculus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3TRQ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3TRQ FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=BMA:BETA-D-MANNOSE'>BMA</scene>, <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=MAN:ALPHA-D-MANNOSE'>MAN</scene>, <scene name='pdbligand=MPD:(4S)-2-METHYL-2,4-PENTANEDIOL'>MPD</scene>, <scene name='pdbligand=MRD:(4R)-2-METHYLPENTANE-2,4-DIOL'>MRD</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene></td></tr> | + | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BMA:BETA-D-MANNOSE'>BMA</scene>, <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=MPD:(4S)-2-METHYL-2,4-PENTANEDIOL'>MPD</scene>, <scene name='pdbligand=MRD:(4R)-2-METHYLPENTANE-2,4-DIOL'>MRD</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</scene>, <scene name='pdbligand=MAN:ALPHA-D-MANNOSE'>MAN</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene></td></tr> |
| - | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[3trp|3trp]]</td></tr> | + | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat"><div style='overflow: auto; max-height: 3em;'>[[3trp|3trp]]</div></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=3trq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3trq OCA], [http://pdbe.org/3trq PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=3trq RCSB], [http://www.ebi.ac.uk/pdbsum/3trq PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=3trq 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=3trq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3trq OCA], [https://pdbe.org/3trq PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3trq RCSB], [https://www.ebi.ac.uk/pdbsum/3trq PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3trq ProSAT]</span></td></tr> |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/CASQ1_RABIT CASQ1_RABIT]] Calsequestrin is a high-capacity, moderate affinity, calcium-binding protein and thus acts as an internal calcium store in muscle. The release of calcium bound to calsequestrin through a calcium release channel triggers muscle contraction. The skeletal muscle isoform (CASQ1) binds around 80 Ca(2+) ions, while the cardiac isoform (CASQ2) binds approximately 60 Ca(2+) ions (By similarity). | + | [[https://www.uniprot.org/uniprot/CASQ1_RABIT CASQ1_RABIT]] Calsequestrin is a high-capacity, moderate affinity, calcium-binding protein and thus acts as an internal calcium store in muscle. The release of calcium bound to calsequestrin through a calcium release channel triggers muscle contraction. The skeletal muscle isoform (CASQ1) binds around 80 Ca(2+) ions, while the cardiac isoform (CASQ2) binds approximately 60 Ca(2+) ions (By similarity). |
| | <div style="background-color:#fffaf0;"> | | <div style="background-color:#fffaf0;"> |
| | == Publication Abstract from PubMed == | | == Publication Abstract from PubMed == |
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| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| | + | [[Category: Large Structures]] |
| | [[Category: Oryctolagus cuniculus]] | | [[Category: Oryctolagus cuniculus]] |
| | [[Category: Kang, C]] | | [[Category: Kang, C]] |
| Structural highlights
3trq is a 1 chain structure with sequence from Oryctolagus cuniculus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
| | Ligands: | , , , , , , |
| Related: | |
| Resources: | FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT |
Function
[CASQ1_RABIT] Calsequestrin is a high-capacity, moderate affinity, calcium-binding protein and thus acts as an internal calcium store in muscle. The release of calcium bound to calsequestrin through a calcium release channel triggers muscle contraction. The skeletal muscle isoform (CASQ1) binds around 80 Ca(2+) ions, while the cardiac isoform (CASQ2) binds approximately 60 Ca(2+) ions (By similarity).
Publication Abstract from PubMed
Calsequestrin (CASQ) serves as a major Ca2+-storage/buffer protein in the sarcoplasmic reticulum (SR). When purified from skeletal muscle, CASQ1 is obtained in its glycosylated form. Here, we have confirmed the specific site and degree of glycosylation of native rabbit CASQ1 (rCASQ1), and have investigated its effect on critical properties of CASQ by comparison with the non-glycosylated recombinant form. Based on our comparative approach utilizing crystal structures, Ca2+-binding capacities, analytical ultracentrifugation, and light scattering profiles of the native and recombinant rCASQ1, we propose a novel and dynamic role for glycosylation in CASQ. CASQ undergoes a unique degree of mannose trimming as it is trafficked from the proximal ER to the SR. The major glycoform of CASQ (GlcNAc2Man9) found in the proximal ER can severely hinder formation of the back-to-back interface, potentially preventing premature Ca2+-dependent polymerization of CASQ, and ensuring its continuous mobility to the SR. Only trimmed glycans can stabilize both front-to-front and the back-to-back interfaces of CASQ through extensive hydrogen bonding and electrostatic interactions. Therefore, the mature glycoform of CASQ (GlcNAc2Man1-4) within the SR can be retained upon establishing a functional high-capacity Ca2+-binding polymer. In addition, based on the high-resolution structures, we propose a molecular mechanism for the catecholaminergic polymorphic ventricular tachycardia (CPVT2) mutation, K206N.
Glycosylation of skeletal calsequestrin, implications for its function.,Sanchez EJ, Lewis KM, Munske GR, Nissen MS, Kang C J Biol Chem. 2011 Dec 14. PMID:22170046[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Sanchez EJ, Lewis KM, Munske GR, Nissen MS, Kang C. Glycosylation of skeletal calsequestrin, implications for its function. J Biol Chem. 2011 Dec 14. PMID:22170046 doi:10.1074/jbc.M111.326363
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