Electrophysiological characterization of long QT syndrome associated mutations V630A and N633S / 中华心血管病杂志
Chinese Journal of Cardiology
; (12): 523-527, 2006.
Article
in Zh
| WPRIM
| ID: wpr-295282
Responsible library:
WPRO
ABSTRACT
<p><b>OBJECTIVE</b>To identify the electrophysiological properties of long-QT syndrome (LQTS) associated missense mutations in the outer mouth of the HERG potassium channel in vitro.</p><p><b>METHODS</b>Mutations V630A and N633S were constructed by Megaprimer PCR method and cRNA were produced by T7 RNA polymerase. The electrophysiological properties of the mutation were investigated in the Xenopus oocyte heterologous expression system.</p><p><b>RESULTS</b>Coexpression of mutant and wild-type HERG subunits caused a dominant-negative effect, and the currents were significantly decreased. Compared with wild-type HERG channels, V630A and N633S mutations were related to decreased time constants for inactivation for V630A/WT and N633S/WT at all potentials, reduced slope conductance and the voltage dependence of steady-state inactivation was shifted to negative potentials for V630A/WT and N633S/WT.</p><p><b>CONCLUSION</b>Present study shows that LQTS associated missense mutations located in the outer mouth of HERG cause a dominant-negative effect and alterations in steady-state voltage dependence of channel gating of heteromultimeric channels suggesting a reduction in expressional current might be one of the pathophysiologic mechanisms of LQTS.</p>
Full text:
1
Index:
WPRIM
Main subject:
Oocytes
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Xenopus
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Long QT Syndrome
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DNA Mutational Analysis
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RNA, Complementary
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Patch-Clamp Techniques
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Mutation, Missense
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Electrocardiography
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Ether-A-Go-Go Potassium Channels
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ERG1 Potassium Channel
Limits:
Animals
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Humans
Language:
Zh
Journal:
Chinese Journal of Cardiology
Year:
2006
Type:
Article