Regulation of Human Cav3.2 T-type Calcium Currents by Calcium Channel γ Subunits

• Main Authors: LIN, YI-JYUN, 林宜君
• Other Authors: CHEN, REN-SHIANG
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/rncbt2

碩士 === 東海大學 === 生命科學系 === 105 === The current conducted by calcium channels mediate many important cellular processes. The dysfunction of calcium channel can cause disorders including epilepsy, arrhythmia and pulmonary hypertension. The voltage-gated calcium channel has up to four subunits (α1, β, α2δ and γ). The α1 subunit forms the calcium-selective channel pore. The β and α2δ subunits help the α1 subunit insert into the plasma membrane, increasing channel open probability and decreasing channel inactivation. In contrast, γ subunits are much less studied. Recently, the γ subunits have added two new members, TMEM114 and TMEM235. Some evidence suggests that TMEM114 may be related to the eye development. The γ6 has been shown to reduce rat Cav3.1 current in HEK cell line and T-type calcium currents in cardiomyocytes, but its regulatory effect on human channels remains elusive. My study was designed to determine whether the rat γ6, TMEM114 and TMEM235 can interact with the trasnfected human Cav3.2 channel in the HEK293 cells. Four of TMEM235 and TMEM114 constructs were successfully cloned into pcDNA3.1 vectors. Electrophysiological recordings of the Cav3.2 channel current with and without the co-expression of rat γ6 subunit in HEK cells indicated that γ6 subunit significantly reduced Cav3.2 current density. The results of interactions between Cav3 channels and these three subunits will contribute to our knowledge of their biological functions, as well as provide therapeutic strategies for treating T-type channel related diseases.