Differential modulations of KCNQ1 by auxiliary proteins KCNE1 and KCNE2.
KCNQ1 channels play vital roles in cardiovascular, gastric and other systems. The conductance and dynamics of KCNQ1 could be modulated by different single transmembrane helical auxiliary proteins (such as KCNE1, KCNE2 and others). In this study, detail KCNQ1 function modulations by different regions of KCNE1 or KCNE2 were examined using combinational methods of electrophysiology, immunofluorescence, solution NMR and related backbone flexibility analysis. In the presence of KCNE2 N-terminus, decreased surface expression and consequent low activities of KCNQ1 were observed. The transmembrane domains (TMDs) of KCNE1 and KCNE2 were illustrated to associate with the KCNQ1 channel in different modes: Ile64 in KCNE2-TMD interacting with Phe340 and Phe275 in KCNQ1, while two pairs of interacting residues (Phe340-Thr58 and Ala244-Tyr65) in the KCNQ1/KCNE1 complex. The KCNE1 C-terminus could modulate gating property of KCNQ1, whereas KCNE2 C-terminus had only minimal influences on KCNQ1. All of the results demonstrated different KCNQ1 function modulations by different regions of the two auxiliary proteins.
1] Hefei National Laboratory for Physical Science at Microscale and School of Life Science, University of Science and Technology of China, Hefei, Anhui, 230027, P. R. China [2].
Pan
P
Li
1] Key laboratory of Molecular Biophysics of the Ministry of Education College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, P, R. China [2].
Haowen
H
Liu
Hefei National Laboratory for Physical Science at Microscale and School of Life Science, University of Science and Technology of China, Hefei, Anhui, 230027, P. R. China.
Chaohua
C
Lai
Hefei National Laboratory for Physical Science at Microscale and School of Life Science, University of Science and Technology of China, Hefei, Anhui, 230027, P. R. China.
Peibei
P
Sun
Key laboratory of Molecular Biophysics of the Ministry of Education College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, P, R. China.
Wenping
W
Zeng
High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, Anhui, 230031, P. R. China.
Fangming
F
Wu
Hefei National Laboratory for Physical Science at Microscale and School of Life Science, University of Science and Technology of China, Hefei, Anhui, 230027, P. R. China.
Longhua
L
Zhang
Key laboratory of Molecular Biophysics of the Ministry of Education College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, P, R. China.
Sheng
S
Wang
1] Hefei National Laboratory for Physical Science at Microscale and School of Life Science, University of Science and Technology of China, Hefei, Anhui, 230027, P. R. China [2] High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, Anhui, 230031, P. R. China.
Changlin
C
Tian
Key laboratory of Molecular Biophysics of the Ministry of Education College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, P, R. China.
Jiuping
J
Ding
D002460:Cell Line; D057809:HEK293 Cells; D006801:Humans; D051657:KCNQ1 Potassium Channel / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism; D008823:Micelles; D024642:Potassium Channels, Voltage-Gated / Q000378:metabolism*; D054730:Protein Interaction Domains and Motifs; D017434:Protein Structure, Tertiary
C489622:KCNE1 protein, human; C489619:KCNE2 protein, human; D051657:KCNQ1 Potassium Channel; C496909:KCNQ1 protein, human; D008565:Membrane Proteins; D008823:Micelles; D024642:Potassium Channels, Voltage-Gated