Molecular Dissection of Ca2+ Efflux in Immortalized Proximal Tubule Cells
Plasma membrane Ca2+-ATPase (PMCA) and the Na+/Ca2+ exchanger participate in regulating cell function by maintaining proper intracellular Ca2+ concentrations ([Ca2+]i). In renal epithelial cells these proteins have been additionally implicated in cellular calcium absorption. The purpose of the prese...
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| Format: | Online |
| Language: | English |
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The Rockefeller University Press
1997
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| Online Access: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2220068/ |
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pubmed-22200682008-04-22 Molecular Dissection of Ca2+ Efflux in Immortalized Proximal Tubule Cells White, Kenneth E. Gesek, Frank A. Nesbitt, Teresa Drezner, Marc K. Friedman, Peter A. Article Plasma membrane Ca2+-ATPase (PMCA) and the Na+/Ca2+ exchanger participate in regulating cell function by maintaining proper intracellular Ca2+ concentrations ([Ca2+]i). In renal epithelial cells these proteins have been additionally implicated in cellular calcium absorption. The purpose of the present studies was to determine the Ca2+ extrusion mechanisms in cells derived from the proximal tubule. Homology-based RT-PCR was used to amplify PMCA transcripts from RNA isolated from mouse cell lines originating from the S1, S2, and S3 proximal tubule segments. S1, S2, and S3 cells exhibited only PMCA1 and PMCA4 products. PCR product identity was confirmed by sequence analysis. Northern analysis of proximal tubule cell RNAs revealed appropriate transcripts of 7.5 and 5.5 kb for PMCA1 and 8.5 and 7.5 kb for PMCA4, but were negative for PMCA2 and PMCA3. Western analysis with a monoclonal antibody to PMCA showed that all proximal cell lines expressed a reacting plasma membrane protein of 140 kD, the reported PMCA molecular mass. Na+/Ca2+ exchanger (NCX1) mRNA expression, analyzed by RT-PCR, protein expression by Western analysis, and functional exchange activity were uniformly absent from all proximal tubule cell lines. These observations support the idea that immortalized cells derived from the proximal tubule express PMCA1 and PMCA4, which may serve as the primary mechanism of cellular Ca2+ efflux. The Rockefeller University Press 1997-02-01 /pmc/articles/PMC2220068/ /pubmed/9041450 Text en This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/4.0/). |
| repository_type |
Open Access Journal |
| institution_category |
Foreign Institution |
| institution |
US National Center for Biotechnology Information |
| building |
NCBI PubMed |
| collection |
Online Access |
| language |
English |
| format |
Online |
| author |
White, Kenneth E. Gesek, Frank A. Nesbitt, Teresa Drezner, Marc K. Friedman, Peter A. |
| spellingShingle |
White, Kenneth E. Gesek, Frank A. Nesbitt, Teresa Drezner, Marc K. Friedman, Peter A. Molecular Dissection of Ca2+ Efflux in Immortalized Proximal Tubule Cells |
| author_facet |
White, Kenneth E. Gesek, Frank A. Nesbitt, Teresa Drezner, Marc K. Friedman, Peter A. |
| author_sort |
White, Kenneth E. |
| title |
Molecular Dissection of Ca2+ Efflux in Immortalized Proximal
Tubule Cells
|
| title_short |
Molecular Dissection of Ca2+ Efflux in Immortalized Proximal
Tubule Cells
|
| title_full |
Molecular Dissection of Ca2+ Efflux in Immortalized Proximal
Tubule Cells
|
| title_fullStr |
Molecular Dissection of Ca2+ Efflux in Immortalized Proximal
Tubule Cells
|
| title_full_unstemmed |
Molecular Dissection of Ca2+ Efflux in Immortalized Proximal
Tubule Cells
|
| title_sort |
molecular dissection of ca2+ efflux in immortalized proximal
tubule cells |
| description |
Plasma membrane Ca2+-ATPase (PMCA) and the Na+/Ca2+ exchanger participate in regulating cell
function by maintaining proper intracellular Ca2+ concentrations ([Ca2+]i). In renal epithelial cells these proteins
have been additionally implicated in cellular calcium absorption. The purpose of the present studies was to determine the Ca2+ extrusion mechanisms in cells derived from the proximal tubule. Homology-based RT-PCR was used
to amplify PMCA transcripts from RNA isolated from mouse cell lines originating from the S1, S2, and S3 proximal
tubule segments. S1, S2, and S3 cells exhibited only PMCA1 and PMCA4 products. PCR product identity was confirmed by sequence analysis. Northern analysis of proximal tubule cell RNAs revealed appropriate transcripts of
7.5 and 5.5 kb for PMCA1 and 8.5 and 7.5 kb for PMCA4, but were negative for PMCA2 and PMCA3. Western
analysis with a monoclonal antibody to PMCA showed that all proximal cell lines expressed a reacting plasma
membrane protein of 140 kD, the reported PMCA molecular mass. Na+/Ca2+ exchanger (NCX1) mRNA expression, analyzed by RT-PCR, protein expression by Western analysis, and functional exchange activity were uniformly absent from all proximal tubule cell lines. These observations support the idea that immortalized cells derived from the
proximal tubule express PMCA1 and PMCA4, which may serve as the primary mechanism of cellular Ca2+ efflux. |
| publisher |
The Rockefeller University Press |
| publishDate |
1997 |
| url |
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2220068/ |
| _version_ |
1611435848042020864 |