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Stem Cells International
Volume 2011, Article ID 456815, 12 pages
Research Article

An Inducible Expression System of the Calcium-Activated Potassium Channel 4 to Study the Differential Impact on Embryonic Stem Cells

1Institute for Anatomy and Cell Biology, Ulm University, 89081 Ulm, Germany
2Department of Internal Medicine I, Ulm University, 89081 Ulm, Germany
3Department of Pediatrics, Lillehei Heart Institute, University of Minnesota, Minneapolis, MN, USA
4Institute of Molecular Medicine and Max-Planck-Research Group on Stem Cell Aging, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany

Received 15 April 2011; Accepted 14 June 2011

Academic Editor: Gabriela Kania

Copyright © 2011 Stefan Liebau et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Rationale. The family of calcium-activated potassium channels consists of four members with varying biological functions and conductances. Besides membrane potential modulation, SK channels have been found to be involved in cardiac pacemaker cell development from ES cells and morphological shaping of neural stem cells. Objective. Distinct SK channel subtype expression in ES cells might elucidate their precise impact during cardiac development. We chose SK channel subtype 4 as a potential candidate influencing embryonic stem cell differentiation. Methods. We generated a doxycycline inducible mouse ES cell line via targeted homologous recombination of a cassette expressing a bicistronic construct encoding SK4 and a fluorophore from the murine HPRT locus. Conclusion. We characterized the mouse ES cell line iSK4-AcGFP. The cassette is readily expressed under the control of doxycycline, and the overexpression of SK4 led to an increase in cardiac and pacemaker cell differentiation thereby serving as a unique tool to characterize the cell biological variances due to specific SK channel overexpression.