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Caloxin 1b3: a novel plasma membrane Ca(2+)-pump isoform 1 selective inhibitor that increases cytosolic Ca(2+) in endothelial cells.
- Source :
-
Cell calcium [Cell Calcium] 2010 Dec; Vol. 48 (6), pp. 352-7. Date of Electronic Publication: 2010 Nov 18. - Publication Year :
- 2010
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Abstract
- The purpose of this study was to invent an extracellular inhibitor selective for the plasma membrane Ca(2+) pump(s) (PMCA) isoform 1. PMCA extrude Ca(2+) from cells during signalling and homeostasis. PMCA isoforms are encoded by 4 genes (PMCA1-4). Pig coronary artery endothelium and smooth muscle express the genes PMCA1 and 4. We showed that the endothelial cells contained mostly PMCA1 protein while smooth muscle cells had mostly PMCA4. A random peptide phage display library was screened for binding to synthetic extracellular domain 1 of PMCA1. The selected phage population was screened further by affinity chromatography using PMCA from rabbit duodenal mucosa which expressed mostly PMCA1. The peptide displayed by the selected phage was termed caloxin 1b3. Caloxin 1b3 inhibited PMCA Ca(2+)-Mg(2+)-ATPase in the rabbit duodenal mucosa (PMCA1) with a greater affinity (inhibition constant=17±2 μM) than the PMCA in the human erythrocyte ghosts (PMCA4, inhibition constant=45±4 μM). The affinity of caloxin 1b3 was also higher for PMCA1 than for PMCA2 and 3 indicating its selectivity for PMCA1. Consistent with an inhibition of PMCA1, caloxin 1b3 addition to the medium increased cytosolic Ca(2+) concentration in endothelial cells. Caloxin 1b3 is the first known PMCA1 selective inhibitor. We anticipate caloxin 1b3 to aid in understanding PMCA physiology in endothelium and other tissues.<br /> (Copyright © 2010 Elsevier Ltd. All rights reserved.)
- Subjects :
- Animals
Ca(2+) Mg(2+)-ATPase antagonists & inhibitors
Ca(2+) Mg(2+)-ATPase metabolism
Cell Membrane drug effects
Cell Membrane enzymology
Coronary Vessels cytology
Coronary Vessels enzymology
Endothelial Cells enzymology
Endothelium, Vascular cytology
Endothelium, Vascular enzymology
Humans
In Vitro Techniques
Intestinal Mucosa drug effects
Intestinal Mucosa enzymology
Isoenzymes antagonists & inhibitors
Isoenzymes metabolism
Myocytes, Smooth Muscle drug effects
Myocytes, Smooth Muscle enzymology
Organ Specificity
Plasma Membrane Calcium-Transporting ATPases metabolism
Rabbits
Solute Carrier Organic Anion Transporter Family Member 1B3
Swine
Calcium metabolism
Endothelial Cells drug effects
Organic Anion Transporters, Sodium-Independent pharmacology
Plasma Membrane Calcium-Transporting ATPases antagonists & inhibitors
Subjects
Details
- Language :
- English
- ISSN :
- 1532-1991
- Volume :
- 48
- Issue :
- 6
- Database :
- MEDLINE
- Journal :
- Cell calcium
- Publication Type :
- Academic Journal
- Accession number :
- 21093050
- Full Text :
- https://doi.org/10.1016/j.ceca.2010.10.008