Milenkovic, Vladimir M., Krejcova, Sarka, Reichhart, Nadine, Wagner, Andrea and Strauss, Olaf
(2011)
Interaction of bestrophin-1 and Ca2+ channel β-subunits: identification of new binding domains on the bestrophin-1 C-terminus.
PloS one 6 (4), e19364.
Date of publication of this fulltext: 11 Apr 2012 09:07at PubMed
at publisher (via DOI)
Abstract
Bestrophin-1 modulates currents through voltage-dependent L-type Ca(2+) channels by physically interacting with the β-subunits of Ca(2+) channels. The main function of β-subunits is to regulate the number of pore-forming Ca(V)-subunits in the cell membrane and modulate Ca(2+) channel currents. To understand the influence of full-length bestrophin-1 on β-subunit function, we studied binding and ...
Abstract
Bestrophin-1 modulates currents through voltage-dependent L-type Ca(2+) channels by physically interacting with the β-subunits of Ca(2+) channels. The main function of β-subunits is to regulate the number of pore-forming Ca(V)-subunits in the cell membrane and modulate Ca(2+) channel currents. To understand the influence of full-length bestrophin-1 on β-subunit function, we studied binding and localization of bestrophin-1 and Ca(2+) channel subunits, together with modulation of Ca(V)1.3 Ca(2+) channels currents. In heterologeous expression, bestrophin-1 showed co-immunoprecipitation with either, β3-, or β4-subunits. We identified a new highly conserved cluster of proline-rich motifs on the bestrophin-1 C-terminus between amino acid position 468 and 486, which enables possible binding to SH3-domains of β-subunits. A bestrophin-1 that lacks these proline-rich motifs (ΔCT-PxxP bestrophin-1) showed reduced efficiency to co-immunoprecipitate with β3 and β4-subunits. In the presence of ΔCT-PxxP bestrophin-1, β4-subunits and Ca(V)1.3 subunits partly lost membrane localization. Currents from Ca(V)1.3 subunits were modified in the presence of β4-subunit and wild-type bestrophin-1: accelerated time-dependent activation and reduced current density. With ΔCTPxxP bestrophin-1, currents showed the same time-dependent activation as with wild-type bestrophin-1, but the current density was further reduced due to decreased number of Ca(2+) channels proteins in the cell membrane. In summary, we described new proline-rich motifs on bestrophin-1 C-terminus, which help to maintain the ability of β-subunits to regulate surface expression of pore-forming Ca(V) Ca(2+)-channel subunits.
Export bibliographical data
| Item type: | Article |
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| Date: | 29 April 2011 |
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| Institutions: | Medicine > Lehrstuhl für Augenheilkunde |
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| Identification Number: | | Value | Type |
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| 15530640 | PubMed ID | | 10.1371/journal.pone.0019364 | DOI |
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| Classification: | | Notation | Type |
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| Amino Acid Motifs | MESH | | Animals | MESH | | CHO Cells | MESH | | Calcium Channels/chemistry | MESH | | Chloride Channels/chemistry | MESH | | Cricetinae | MESH | | Cricetulus | MESH | | Eye Proteins/chemistry | MESH | | HEK293 Cells | MESH | | Humans | MESH | | Microscopy, Confocal/methods | MESH | | Patch-Clamp Techniques | MESH | | Protein Binding | MESH | | Protein Conformation | MESH | | Protein Structure, Secondary | MESH | | Protein Structure, Tertiary | MESH |
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| Dewey Decimal Classification: | 600 Technology > 610 Medical sciences Medicine |
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| Status: | Published |
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| Refereed: | Yes, this version has been refereed |
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| Created at the University of Regensburg: | Yes |
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| Item ID: | 23751 |
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