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Interspecies differences in PTH-mediated PKA phosphorylation of the epithelial calcium channel TRPV5
The epithelial calcium (Ca(2+)) channel TRPV5 (transient receptor potential vanilloid 5) is expressed in the distal convoluted tubule of the kidney and facilitates active Ca(2+) reabsorption. This process is instrumental for the maintenance of Ca(2+) homeostasis. Therefore, all aspects of TRPV5 func...
Autores principales: | , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Springer Berlin Heidelberg
2017
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5590029/ https://www.ncbi.nlm.nih.gov/pubmed/28534087 http://dx.doi.org/10.1007/s00424-017-1996-9 |
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author | van Goor, Mark K Verkaart, Sjoerd van Dam, Teunis J Huynen, Martijn A van der Wijst, Jenny |
author_facet | van Goor, Mark K Verkaart, Sjoerd van Dam, Teunis J Huynen, Martijn A van der Wijst, Jenny |
author_sort | van Goor, Mark K |
collection | PubMed |
description | The epithelial calcium (Ca(2+)) channel TRPV5 (transient receptor potential vanilloid 5) is expressed in the distal convoluted tubule of the kidney and facilitates active Ca(2+) reabsorption. This process is instrumental for the maintenance of Ca(2+) homeostasis. Therefore, all aspects of TRPV5 function are tightly regulated by the calciotropic parathyroid hormone (PTH). Rabbit (rb)TRPV5 channel activity was shown to be stimulated upon PTH-mediated protein kinase A (PKA) phosphorylation. Since there is incomplete conservation of the PKA consensus motif (RR/QxT) across species, the aim of this study was to extend these findings to humans and characterize the expression and function of human (h)TRPV5. Functional differences between rbTRPV5 and hTRPV5 upon PTH stimulation were investigated using (45)Ca(2+) uptake assays, Fura-2 Ca(2+) imaging, and cell surface biotinylation. While PTH treatment enhanced rbTRPV5 channel activity, it did not stimulate hTRPV5 activity. Mutation of the human RQxT motif into rabbit RRxT (hTRPV5 Q706R) partially restored the sensitivity to PTH. An ancestral sequence reconstruction of TRPV5 orthologues demonstrated that the change in the RRxT motif coincides with the creation of another putative PKA motif (RGAS to RRAS) in the amino terminus of hTRPV5. Interestingly, a constitutively phosphorylated hTRPV5 mutant (hTRPV5 S141D) displayed significantly decreased channel function, while its plasma membrane abundance was increased. Taken together, PTH-mediated stimulation of TRPV5, via PKA, is not conserved in humans. Our data suggest that PTH regulation of TRPV5 is altered in humans, an important observation for future studies that may add to new concepts on the role of PTH in renal Ca(2+) handling. |
format | Online Article Text |
id | pubmed-5590029 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2017 |
publisher | Springer Berlin Heidelberg |
record_format | MEDLINE/PubMed |
spelling | pubmed-55900292017-09-22 Interspecies differences in PTH-mediated PKA phosphorylation of the epithelial calcium channel TRPV5 van Goor, Mark K Verkaart, Sjoerd van Dam, Teunis J Huynen, Martijn A van der Wijst, Jenny Pflugers Arch Ion Channels, Receptors and Transporters The epithelial calcium (Ca(2+)) channel TRPV5 (transient receptor potential vanilloid 5) is expressed in the distal convoluted tubule of the kidney and facilitates active Ca(2+) reabsorption. This process is instrumental for the maintenance of Ca(2+) homeostasis. Therefore, all aspects of TRPV5 function are tightly regulated by the calciotropic parathyroid hormone (PTH). Rabbit (rb)TRPV5 channel activity was shown to be stimulated upon PTH-mediated protein kinase A (PKA) phosphorylation. Since there is incomplete conservation of the PKA consensus motif (RR/QxT) across species, the aim of this study was to extend these findings to humans and characterize the expression and function of human (h)TRPV5. Functional differences between rbTRPV5 and hTRPV5 upon PTH stimulation were investigated using (45)Ca(2+) uptake assays, Fura-2 Ca(2+) imaging, and cell surface biotinylation. While PTH treatment enhanced rbTRPV5 channel activity, it did not stimulate hTRPV5 activity. Mutation of the human RQxT motif into rabbit RRxT (hTRPV5 Q706R) partially restored the sensitivity to PTH. An ancestral sequence reconstruction of TRPV5 orthologues demonstrated that the change in the RRxT motif coincides with the creation of another putative PKA motif (RGAS to RRAS) in the amino terminus of hTRPV5. Interestingly, a constitutively phosphorylated hTRPV5 mutant (hTRPV5 S141D) displayed significantly decreased channel function, while its plasma membrane abundance was increased. Taken together, PTH-mediated stimulation of TRPV5, via PKA, is not conserved in humans. Our data suggest that PTH regulation of TRPV5 is altered in humans, an important observation for future studies that may add to new concepts on the role of PTH in renal Ca(2+) handling. Springer Berlin Heidelberg 2017-05-22 2017 /pmc/articles/PMC5590029/ /pubmed/28534087 http://dx.doi.org/10.1007/s00424-017-1996-9 Text en © The Author(s) 2017 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. |
spellingShingle | Ion Channels, Receptors and Transporters van Goor, Mark K Verkaart, Sjoerd van Dam, Teunis J Huynen, Martijn A van der Wijst, Jenny Interspecies differences in PTH-mediated PKA phosphorylation of the epithelial calcium channel TRPV5 |
title | Interspecies differences in PTH-mediated PKA phosphorylation of the epithelial calcium channel TRPV5 |
title_full | Interspecies differences in PTH-mediated PKA phosphorylation of the epithelial calcium channel TRPV5 |
title_fullStr | Interspecies differences in PTH-mediated PKA phosphorylation of the epithelial calcium channel TRPV5 |
title_full_unstemmed | Interspecies differences in PTH-mediated PKA phosphorylation of the epithelial calcium channel TRPV5 |
title_short | Interspecies differences in PTH-mediated PKA phosphorylation of the epithelial calcium channel TRPV5 |
title_sort | interspecies differences in pth-mediated pka phosphorylation of the epithelial calcium channel trpv5 |
topic | Ion Channels, Receptors and Transporters |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5590029/ https://www.ncbi.nlm.nih.gov/pubmed/28534087 http://dx.doi.org/10.1007/s00424-017-1996-9 |
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