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Titles listAn ether -a-go-go K+ current, Ih-eag, contributes to the hyperpolarization of human fusion-competent myoblasts
Titles listAn ether -a-go-go K+ current, Ih-eag, contributes to the hyperpolarization of human fusion-competent myoblasts
Scientific Article
unige:10192 
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An ether -a-go-go K+ current, Ih-eag, contributes to the hyperpolarization of human fusion-competent myoblasts |
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| Authors | ||
| Published in | The Journal of Physiology. 1998, vol. 512, no. 2, p. 317-323 | |
| Abstract | 1. Two early signs of human myoblast commitment to fusion are membrane potential hyperpolarization and concomitant expression of a non-inactivating delayed rectifier K+ current, IK(NI). This current closely resembles the outward K+ current elicited by rat ether-a-go-go (r-eag) channels in its range of potential for activation and unitary conductance. 2. It is shown that activation kinetics of IK(NI), like those of r-eag, depend on holding potential and on [Mg2+]o, and that IK(NI), like r-eag, is reversibly inhibited by a rise in [Ca2+]i. 3. Forced expression of an isolated human ether-a-go-go K+ channel (h-eag) cDNA in undifferentiated myoblasts generates single-channel and whole-cell currents with remarkable similarity to IK(NI). 4. h-eag current (Ih-eag) is reversibly inhibited by a rise in [Ca2+]i, and the activation kinetics depend on holding potential and [Mg2+]o. 5. Forced expression of h-eag hyperpolarizes undifferentiated myoblasts from -9 to -50 mV, the threshold for the activation of both Ih-eag and IK(NI). Similarly, the higher the density of IK(NI), the more hyperpolarized the resting potential of fusion-competent myoblasts. 6. It is concluded that h-eag constitutes the channel underlying IK(NI) and that it contributes to the hyperpolarization of fusion-competent myoblasts. To our knowledge, this is the first demonstration of a physiological role for a mammalian eag K+ channel. | |
| Keywords | Adolescent — Algorithms — Animals — Calcium/metabolism — Cell Differentiation/physiology — Cell Fusion/physiology — Cell Polarity/ physiology — Cells, Cultured — Child — Child, Preschool — Electric Stimulation — Electrophysiology — Ether-A-Go-Go Potassium Channels — Humans — Infant — Membrane Potentials/physiology — Muscle Development — Muscle, Skeletal/cytology/growth & development/ metabolism — Patch-Clamp Techniques — Potassium Channels/ metabolism — Rats | |
| Identifiers | PMID: 9763622 | |
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| Citation (ISO format) | BIJLENGA, P. et al. An ether -a-go-go K+ current, Ih-eag, contributes to the hyperpolarization of human fusion-competent myoblasts. In: The Journal of Physiology, 1998, vol. 512, n° 2, p. 317-323. doi: 10.1111/j.1469-7793.1998.317be.x https://archive-ouverte.unige.ch/unige:10192 |
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