Pivoting between calmodulin lobes triggered by calcium in the Kv7.2/calmodulin complex.
Kv7.2 (KCNQ2) is the principal molecular component of the slow voltage gated M-channel, which strongly influences neuronal excitability. Calmodulin (CaM) binds to two intracellular C-terminal segments of Kv7.2 channels, helices A and B, and it is required for exit from the endoplasmic reticulum. How...
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doaj-dca1fc06521041f5b0972c7720bcbb4a2021-03-04T09:57:30ZengPublic Library of Science (PLoS)PLoS ONE1932-62032014-01-0191e8671110.1371/journal.pone.0086711Pivoting between calmodulin lobes triggered by calcium in the Kv7.2/calmodulin complex.Alessandro AlaimoAraitz AlberdiCarolina Gomis-PerezJuncal Fernández-OrthGaneko Bernardo-SeisdedosCovadonga MaloOscar MilletPilar AresoAlvaro VillarroelKv7.2 (KCNQ2) is the principal molecular component of the slow voltage gated M-channel, which strongly influences neuronal excitability. Calmodulin (CaM) binds to two intracellular C-terminal segments of Kv7.2 channels, helices A and B, and it is required for exit from the endoplasmic reticulum. However, the molecular mechanisms by which CaM controls channel trafficking are currently unknown. Here we used two complementary approaches to explore the molecular events underlying the association between CaM and Kv7.2 and their regulation by Ca(2+). First, we performed a fluorometric assay using dansylated calmodulin (D-CaM) to characterize the interaction of its individual lobes to the Kv7.2 CaM binding site (Q2AB). Second, we explored the association of Q2AB with CaM by NMR spectroscopy, using (15)N-labeled CaM as a reporter. The combined data highlight the interdependency of the N- and C-lobes of CaM in the interaction with Q2AB, suggesting that when CaM binds Ca(2+) the binding interface pivots between the N-lobe whose interactions are dominated by helix B and the C-lobe where the predominant interaction is with helix A. In addition, Ca(2+) makes CaM binding to Q2AB more difficult and, reciprocally, the channel weakens the association of CaM with Ca(2+).https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/24489773/pdf/?tool=EBI |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Alessandro Alaimo Araitz Alberdi Carolina Gomis-Perez Juncal Fernández-Orth Ganeko Bernardo-Seisdedos Covadonga Malo Oscar Millet Pilar Areso Alvaro Villarroel |
spellingShingle |
Alessandro Alaimo Araitz Alberdi Carolina Gomis-Perez Juncal Fernández-Orth Ganeko Bernardo-Seisdedos Covadonga Malo Oscar Millet Pilar Areso Alvaro Villarroel Pivoting between calmodulin lobes triggered by calcium in the Kv7.2/calmodulin complex. PLoS ONE |
author_facet |
Alessandro Alaimo Araitz Alberdi Carolina Gomis-Perez Juncal Fernández-Orth Ganeko Bernardo-Seisdedos Covadonga Malo Oscar Millet Pilar Areso Alvaro Villarroel |
author_sort |
Alessandro Alaimo |
title |
Pivoting between calmodulin lobes triggered by calcium in the Kv7.2/calmodulin complex. |
title_short |
Pivoting between calmodulin lobes triggered by calcium in the Kv7.2/calmodulin complex. |
title_full |
Pivoting between calmodulin lobes triggered by calcium in the Kv7.2/calmodulin complex. |
title_fullStr |
Pivoting between calmodulin lobes triggered by calcium in the Kv7.2/calmodulin complex. |
title_full_unstemmed |
Pivoting between calmodulin lobes triggered by calcium in the Kv7.2/calmodulin complex. |
title_sort |
pivoting between calmodulin lobes triggered by calcium in the kv7.2/calmodulin complex. |
publisher |
Public Library of Science (PLoS) |
series |
PLoS ONE |
issn |
1932-6203 |
publishDate |
2014-01-01 |
description |
Kv7.2 (KCNQ2) is the principal molecular component of the slow voltage gated M-channel, which strongly influences neuronal excitability. Calmodulin (CaM) binds to two intracellular C-terminal segments of Kv7.2 channels, helices A and B, and it is required for exit from the endoplasmic reticulum. However, the molecular mechanisms by which CaM controls channel trafficking are currently unknown. Here we used two complementary approaches to explore the molecular events underlying the association between CaM and Kv7.2 and their regulation by Ca(2+). First, we performed a fluorometric assay using dansylated calmodulin (D-CaM) to characterize the interaction of its individual lobes to the Kv7.2 CaM binding site (Q2AB). Second, we explored the association of Q2AB with CaM by NMR spectroscopy, using (15)N-labeled CaM as a reporter. The combined data highlight the interdependency of the N- and C-lobes of CaM in the interaction with Q2AB, suggesting that when CaM binds Ca(2+) the binding interface pivots between the N-lobe whose interactions are dominated by helix B and the C-lobe where the predominant interaction is with helix A. In addition, Ca(2+) makes CaM binding to Q2AB more difficult and, reciprocally, the channel weakens the association of CaM with Ca(2+). |
url |
https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/24489773/pdf/?tool=EBI |
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