Studies of the function of KCNQ4 and its binding sites interact with KCNQ openers
| Autor: | Yi-Shun Fang, 房義順 |
|---|---|
| Rok vydání: | 2014 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 102 The family of KCNQ (Kv7) voltage-gated potassium channels consists of five members (Kv7.1 to Kv7.5). In this study, we investigated the function of KCNQ4 (Kv7.4) and its binding sites interact with KCNQ openers. We constructed human KCNQ4 and point mutant with pcDNA3.1 plasmid. KCNQ4/pcDNA3.1 was expressed in HEK293t cells and analyzed its conducted voltage-gated potassium channel current. The tail currents analysis of KCNQ4 channels was using the whole-cell patch clamp technique. We constructed R168A, W242L, R488A, R490A, R492A and S494A by site-directed point mutation. Our results showed that the half-activation potential of R168A, W242L, and R492A were -21.8±0.7 mV, -21.5±1.1 mV, -20.6±0.9 mV, respectively. There are no significant difference between WT (-17.7±1.0 mV), R168A, W242L and R492A in half-activation potential. However, the half-activation potential of R488A, R490A and S494A (-29.7±0.5 mV, -25.0±1.1 mV, -29.0±0.8 mV) was shifted more negative than that of WT. Treatment with the selective KCNQ family opener, retigabine, in WT and R168A can produce a V1/2 shifted to a more negative potentials. On the other hand, W242L, R488A, R490A, R492A and S494A did not produce a significant shift in the V1/2 of activation curves after the treatment of retigabine. These data suggested that W242, R488, R490, R492 and S494 are may be involved in the binding of retigabine to the KCNQ4 channels. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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