Shedding Light on the Na+/Ca2+ Exchanger.
From: Department of Physiology, Cardiovascular Research Laboratories, MRL 3-645, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095-1760, USA. mottolia@mednet.ucla.edu
Annals of the New York Academy of Sciences
- Publish Date: Mar 2007
- ISSN: 0077-8923
- Volume: 1099
- Issue:
- Pages: 78-85
- Medium: Print
- Language: English
- Citation (JAMA): Ottolia Michela, John Scott, Xie Yi, et al. Shedding Light on the Na+/Ca2+ Exchanger.. Ann. N. Y. Acad. Sci. Mar 2007;1099:78-85
Abstract
The Na+/Ca2+ exchanger (NCX) regulates cardiac contractility by adjusting the amount of Ca2+ inside myocytes. NCX accomplishes this by using the electrochemical gradient of Na+: during each cycle three Na+ ions enter the cell and one Ca2+ ion is extruded against its gradient. In addition to being transported, cytoplasmic Na+ and Ca2+ ions also regulate exchanger activity. The physiological relevance and molecular processes underlying ionic regulation remain unclear. Also unresolved are the events that regulate NCX trafficking to the membrane and its oligomeric state. This is essential information to interpret structure-function data. The full-length exchanger was fused to both CFP and YFP, creating active fluorescent exchangers used in FRET experiments to assess both conformational changes associated with ionic regulation and the oligomeric state of NCX. Electrophysiological characterization demonstrates that these constructs behave similarly to the wild-type (WT) exchanger. We have been able for the first time to monitor conformational changes of the exchanger Ca2+-binding site in vivo. These studies provide a better understanding of the molecular properties of the NCX.
Mesh Headings (Keywords): Animals, Biopolymers, Fluorescence Resonance Energy Transfer, Humans, Protein Conformation, Sodium-Calcium Exchanger, Xenopus
Check for Full Text / PubMed Unique Identifier (PMID): 17446447
This abstract is part of PubMed, a service of the U.S. National Library of Medicine. PubMed includes more than 17 million citations from MEDLINE and other life science journals for biomedical articles. See Copyright and Disclaimers.
Linked medical terms appearing on this page are added by Healia to help readers find more information and are not part of the original PubMed document.
The data herein was last updated on July 8th, 2008 and may not reflect the most current and accurate data available from NLM.