Conformational Changes of a Ca2+-Binding Domain of the Na+ -Ca2+ Exchanger Monitored by FRET in Transgenic Zebrafish Heart
- Xie, Y., Ottolia, M., John, S., Chen, J.N., and Philipson, K.D.
- American journal of physiology. Cell physiology 295(2): C388-C393 (Journal)
- Registered Authors
- Chen, Jau-Nian
- Ca2+-binding domain, sodium-calcium exchange, zebrafish, FRET
- MeSH Terms
- Animals, Genetically Modified
- Calcium Signaling/drug effects
- Calcium Signaling/physiology
- DNA, Antisense/genetics
- Embryo, Nonmammalian/physiology
- Fluorescence Resonance Energy Transfer*
- Heart/drug effects
- Myocardial Contraction/drug effects
- Myocardial Contraction/physiology
- Peptide Fragments/genetics
- Protein Conformation
- Protein Structure, Tertiary/genetics
- Sodium-Calcium Exchanger/chemistry
- Sodium-Calcium Exchanger/physiology*
- Troponin T/genetics
- Zebrafish Proteins/genetics
- Zebrafish Proteins/physiology*
- 18550703 Full text @ Am. J. Physiol. Cell Physiol.
Xie, Y., Ottolia, M., John, S., Chen, J.N., and Philipson, K.D. (2008) Conformational Changes of a Ca2+-Binding Domain of the Na+ -Ca2+ Exchanger Monitored by FRET in Transgenic Zebrafish Heart. American journal of physiology. Cell physiology. 295(2):C388-C393.
The Na(+) -Ca(2+) exchanger is the major Ca(2+) extrusion mechanism in cardiac myocytes. The activity of the cardiac Na(+)-Ca(2+) exchanger is dynamically regulated by intracellular Ca(2+). Previous studies indicate that Ca(2+) binding to a high-affinity Ca(2+)-binding domain (CBD1) in the large intracellular loop is involved in regulation. We generated transgenic zebrafish with cardiac-specific expression of CBD1 linked to YFP and CFP. Ca(2+)-binding to CBD1 induces conformational changes as detected by FRET. With this transgenic fish model, we were able to monitor conformational changes of the Ca(2+) regulatory domain of NCX in intact hearts. Treatment with the positive inotropic agents ouabain and isoproterenol increased both Ca(2+) transients and Ca(2+)-induced changes in FRET. The results indicate that Ca(2+) regulation of the Na(+)-Ca(2+) exchanger domain CBD1 changes with inotropic state. The transgenic fish models will be useful to further characterize the regulatory properties of the Na(+)-Ca(2+) exchanger in vivo. Key words: Ca2+-binding domain, sodium-calcium exchange, zebrafish, FRET.
Genes / Markers
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Engineered Foreign Genes