The metal-ion-dependent adhesion site in the Von Willebrand factor-A domain of α2δ ö subunits is key to trafficking voltage-gated Ca2+ channels.
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| Title: | The metal-ion-dependent adhesion site in the Von Willebrand factor-A domain of α |
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| Authors: | Canti, C.1, Nieto-Rostro, M.1, Foucault, I.1, Heblich, F.1, Wratten, J.1, Richards, M. W.1, Hendrich, J.1, Douglas, L.1, Page, K. M.1, Davies, A.1, Doiphin, A. C.1 a.dolphin@ucl.ac.uk |
| Source: | Proceedings of the National Academy of Sciences of the United States of America. 8/9/2005, Vol. 102 Issue 32, p11230-11235. 6p. |
| Subjects: | Adhesion, Adsorption (Chemistry), Cohesion, Abherents, Von Willebrand factor, Blood coagulation factors |
| Abstract: | All auxiliary α2δ subunits of voltage-gated Ca2+ (Cav) channels contain an extracellular Von Willebrand factor-A (VWA) domain that, in α2δ-1 and -2, has a perfect metal-ion-dependent adhesion site (MIDAS). Modeling of the α2δ-2 VWA domain shows it to be highly likely to bind a divalent cation. Mutating the three key MIDAS residues responsible for divalent cation binding resulted in a MIDAS mutant α2δ-2 subunit that was still processed and trafficked normally when it was expressed alone. However, unlike WT α2δ-2, the MIDAS mutant α2δ-2 subunit did not enhance and, in some cases, further diminished Cav1.2, -2.1, and -2.2 currents coexpressed with β1b by using either Ba2+ or Na+ as a permeant ion. Furthermore, expression of the MIDAS mutant α2δ-2 reduced surface expression and strongly increased the perinuclear retention of Cavα1 subunits at the earliest time at which expression was observed in both Cos-7 and NG108-15 cells. Despite the presence of endogenous α2δ subunits, heterologous expression of α2δ-2 in differentiated NG108-15 cells further enhanced the endogenous high-threshold Ca2+ currents, whereas this enhancement was prevented by the MIDAS mutations. Our results indicate that α2δ subunits normally interact with the Cavα1 subunit early in their maturation, before the appearance of functional plasma membrane channels, and an intact MIDAS motif in the α2δ subunit is required to promote trafficking of the α1 subunit to the plasma membrane by an integrin-like switch. This finding provides evidence for a primary role of a VWA domain in intracellular trafficking of a multimeric complex, in contrast to the more usual roles in binding extracellular ligands in other exofacial VWA domains. [ABSTRACT FROM AUTHOR] |
| Copyright of Proceedings of the National Academy of Sciences of the United States of America is the property of National Academy of Sciences and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
| FullText | Text: Availability: 0 |
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| Header | DbId: egs DbLabel: Engineering Source An: 18052167 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: The metal-ion-dependent adhesion site in the Von Willebrand factor-A domain of α<subscript>2</subscript>δ ö subunits is key to trafficking voltage-gated Ca<superscript>2+</superscript> channels. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Canti%2C+C%2E%22">Canti, C.</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Nieto-Rostro%2C+M%2E%22">Nieto-Rostro, M.</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Foucault%2C+I%2E%22">Foucault, I.</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Heblich%2C+F%2E%22">Heblich, F.</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Wratten%2C+J%2E%22">Wratten, J.</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Richards%2C+M%2E+W%2E%22">Richards, M. W.</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Hendrich%2C+J%2E%22">Hendrich, J.</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Douglas%2C+L%2E%22">Douglas, L.</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Page%2C+K%2E+M%2E%22">Page, K. M.</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Davies%2C+A%2E%22">Davies, A.</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Doiphin%2C+A%2E+C%2E%22">Doiphin, A. C.</searchLink><relatesTo>1</relatesTo><i> a.dolphin@ucl.ac.uk</i> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Proceedings+of+the+National+Academy+of+Sciences+of+the+United+States+of+America%22">Proceedings of the National Academy of Sciences of the United States of America</searchLink>. 8/9/2005, Vol. 102 Issue 32, p11230-11235. 6p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Adhesion%22">Adhesion</searchLink><br /><searchLink fieldCode="DE" term="%22Adsorption+%28Chemistry%29%22">Adsorption (Chemistry)</searchLink><br /><searchLink fieldCode="DE" term="%22Cohesion%22">Cohesion</searchLink><br /><searchLink fieldCode="DE" term="%22Abherents%22">Abherents</searchLink><br /><searchLink fieldCode="DE" term="%22Von+Willebrand+factor%22">Von Willebrand factor</searchLink><br /><searchLink fieldCode="DE" term="%22Blood+coagulation+factors%22">Blood coagulation factors</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: All auxiliary α2δ subunits of voltage-gated Ca2+ (Cav) channels contain an extracellular Von Willebrand factor-A (VWA) domain that, in α2δ-1 and -2, has a perfect metal-ion-dependent adhesion site (MIDAS). Modeling of the α2δ-2 VWA domain shows it to be highly likely to bind a divalent cation. Mutating the three key MIDAS residues responsible for divalent cation binding resulted in a MIDAS mutant α2δ-2 subunit that was still processed and trafficked normally when it was expressed alone. However, unlike WT α2δ-2, the MIDAS mutant α2δ-2 subunit did not enhance and, in some cases, further diminished Cav1.2, -2.1, and -2.2 currents coexpressed with β1b by using either Ba2+ or Na+ as a permeant ion. Furthermore, expression of the MIDAS mutant α2δ-2 reduced surface expression and strongly increased the perinuclear retention of Cavα1 subunits at the earliest time at which expression was observed in both Cos-7 and NG108-15 cells. Despite the presence of endogenous α2δ subunits, heterologous expression of α2δ-2 in differentiated NG108-15 cells further enhanced the endogenous high-threshold Ca2+ currents, whereas this enhancement was prevented by the MIDAS mutations. Our results indicate that α2δ subunits normally interact with the Cavα1 subunit early in their maturation, before the appearance of functional plasma membrane channels, and an intact MIDAS motif in the α2δ subunit is required to promote trafficking of the α1 subunit to the plasma membrane by an integrin-like switch. This finding provides evidence for a primary role of a VWA domain in intracellular trafficking of a multimeric complex, in contrast to the more usual roles in binding extracellular ligands in other exofacial VWA domains. [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Proceedings of the National Academy of Sciences of the United States of America is the property of National Academy of Sciences and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1073/pnas.0504183102 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 6 StartPage: 11230 Subjects: – SubjectFull: Adhesion Type: general – SubjectFull: Adsorption (Chemistry) Type: general – SubjectFull: Cohesion Type: general – SubjectFull: Abherents Type: general – SubjectFull: Von Willebrand factor Type: general – SubjectFull: Blood coagulation factors Type: general Titles: – TitleFull: The metal-ion-dependent adhesion site in the Von Willebrand factor-A domain of α2δ ö subunits is key to trafficking voltage-gated Ca2+ channels. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Canti, C. – PersonEntity: Name: NameFull: Nieto-Rostro, M. – PersonEntity: Name: NameFull: Foucault, I. – PersonEntity: Name: NameFull: Heblich, F. – PersonEntity: Name: NameFull: Wratten, J. – PersonEntity: Name: NameFull: Richards, M. W. – PersonEntity: Name: NameFull: Hendrich, J. – PersonEntity: Name: NameFull: Douglas, L. – PersonEntity: Name: NameFull: Page, K. M. – PersonEntity: Name: NameFull: Davies, A. – PersonEntity: Name: NameFull: Doiphin, A. C. IsPartOfRelationships: – BibEntity: Dates: – D: 09 M: 08 Text: 8/9/2005 Type: published Y: 2005 Identifiers: – Type: issn-print Value: 00278424 Numbering: – Type: volume Value: 102 – Type: issue Value: 32 Titles: – TitleFull: Proceedings of the National Academy of Sciences of the United States of America Type: main |
| ResultId | 1 |