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-Structure paper
タイトル | EMC chaperone-Ca structure reveals an ion channel assembly intermediate. |
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ジャーナル・号・ページ | Nature, Vol. 619, Issue 7969, Page 410-419, Year 2023 |
掲載日 | 2023年5月17日 |
著者 | Zhou Chen / Abhisek Mondal / Fayal Abderemane-Ali / Seil Jang / Sangeeta Niranjan / José L Montaño / Balyn W Zaro / Daniel L Minor / |
PubMed 要旨 | Voltage-gated ion channels (VGICs) comprise multiple structural units, the assembly of which is required for function. Structural understanding of how VGIC subunits assemble and whether chaperone ...Voltage-gated ion channels (VGICs) comprise multiple structural units, the assembly of which is required for function. Structural understanding of how VGIC subunits assemble and whether chaperone proteins are required is lacking. High-voltage-activated calcium channels (Cas) are paradigmatic multisubunit VGICs whose function and trafficking are powerfully shaped by interactions between pore-forming Ca1 or Ca2 Caα (ref. ), and the auxiliary Caβ and Caαδ subunits. Here we present cryo-electron microscopy structures of human brain and cardiac Ca1.2 bound with Caβ to a chaperone-the endoplasmic reticulum membrane protein complex (EMC)-and of the assembled Ca1.2-Caβ-Caαδ-1 channel. These structures provide a view of an EMC-client complex and define EMC sites-the transmembrane (TM) and cytoplasmic (Cyto) docks; interaction between these sites and the client channel causes partial extraction of a pore subunit and splays open the Caαδ-interaction site. The structures identify the Caαδ-binding site for gabapentinoid anti-pain and anti-anxiety drugs, show that EMC and Caαδ interactions with the channel are mutually exclusive, and indicate that EMC-to-Caαδ hand-off involves a divalent ion-dependent step and Ca1.2 element ordering. Disruption of the EMC-Ca complex compromises Ca function, suggesting that the EMC functions as a channel holdase that facilitates channel assembly. Together, the structures reveal a Ca assembly intermediate and EMC client-binding sites that could have wide-ranging implications for the biogenesis of VGICs and other membrane proteins. |
リンク | Nature / PubMed:37196677 / PubMed Central |
手法 | EM (単粒子) |
解像度 | 3.3 - 3.6 Å |
構造データ | EMDB-28375: Structure of the human L-type voltage-gated calcium channel Cav1.2 complexed with L-leucine (CABAD Map 2) EMDB-28376: Structure of a human EMC:human Cav1.2 channel complex in GDN detergent (ECAB Map 3) EMDB-28561: Human L-type voltage-gated calcium channel Cav1.2 complexed with L-leucine (Segment Map 01) EMDB-28564: Human L-type voltage-gated calcium channel Cav1.2 complexed with L-leucine (Segment Map 02) EMDB-28578: Human EMC:human Cav1.2 channel complex (Segment map 01) EMDB-28579: Human EMC:human Cav1.2 channel complex in GDN detergent (Segment map 02) EMDB-40559: Human EMC:human Cav1.2 channel complex in GDN detergent (ECAB Map 1, Consensus Map) EMDB-40560: Human EMC:human Cav1.2 channel complex in GDN detergent (ECAB Map 2, Consensus Map) EMDB-40561: Human L-type voltage-gated calcium channel Cav1.2 (CABAD Map 1, Consensus Map) |
化合物 | ChemComp-NAG: ChemComp-CA: ChemComp-NA: ChemComp-LEU: ChemComp-CLR: ChemComp-WNZ: ChemComp-WO9: ChemComp-HOH: ChemComp-9Z9: |
由来 |
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キーワード | MEMBRANE PROTEIN / voltage-gated calcium channel / CaV alpha2delta / drug binding / gabapentinoid / endoplasmic reticulum membrane protein complex / holdase / biogenesis |