A Study On The Interaction Of Cardiac Potassium Channels

Potassium channel, which leads in both the quantum and variety of multiple cardiac ion channels, including sodium, potassium, calcium and chlorine channel, is reported as a hotspot due to its correlation to the inborn long QT Syndrome (LQTS). KCNQ1, a voltage-gated potassium channel discovered in the chromosome from an inherited LQTS case for the first time, is closely related to this LQTS. The KCNE1 gene encoded potassium channel is an important auxiliary subunit of KCNQ1 channel. The complex of KCNE1 and KCNQ1 works as a functional channel, the mechanism of which is still under veiled. It is reported that more than 50% of LQTS is related to KCNQ1 gene or KCNE1 gene, while the underlying reason why these mutants can lead to the diseases is still waiting to be uncovered.In our study, we did a preliminary research on the interaction between KCNQ1 and KCNE1, by the method of constructing mutated plasmids of each gene and expressed in HEK-293 or CHO cell lines. We worked both on the channel's kinetics characteristics and membrane expression using immunofluorescence imaging, fluorescence protein imaging and electrophysiological techniques. The results indicated the RXR motif would be an ER retention signal, and KCNQ1's membrane expression weakened with the decrease of the hydrophobicity of the residue X. The results from expression of KCNQ1 alone in either HEK-293 or CHO cells can help us go further in the research of the binding sites and model of KCNQ1 and KCNE1.