Intracellular regions of the Eag potassium channel play a critical role in generation of voltage-dependent currents.
Folding, assembly, and trafficking of ion channels are tightly controlled processes and are important for biological functions relevant to health and disease. Here, we report that functional expression of the Eag channel is temperature-sensitive by a mechanism that is independent of trafficking or surface targeting of the channel protein. Eag channels in cells grown at 37 °C exhibit voltage-evoked gating charge movements but fail to conduct K(+) ions. By mutagenesis and chimeric channel studies, we show that the N- and C-terminal regions are involved in controlling a step after movement of the voltage sensor, as well as in regulating biophysical properties of the Eag channel. Synthesis and assembly of Eag at high temperature disrupt the ability of these domains to carry out their function. These results suggest an important role of the intracellular regions in the generation of Eag currents.
Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, Florida 32306, USA. liyong68@shsmu.edu.cn
Yong
Y
Li
Xinqiu
X
Liu
Yuying
Y
Wu
Zhe
Z
Xu
Hongqin
H
Li
Leslie C
LC
Griffith
Yi
Y
Zhou
D000595:Amino Acid Sequence; D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D004330:Drosophila / Q000502:physiology*; D029721:Drosophila Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D051638:Ether-A-Go-Go Potassium Channels / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D015640:Ion Channel Gating / Q000502:physiology*; D008564:Membrane Potentials / Q000502:physiology; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D016296:Mutagenesis; D011188:Potassium / Q000378:metabolism*; D017510:Protein Folding; D017434:Protein Structure, Tertiary; D021381:Protein Transport / Q000502:physiology*; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013696:Temperature
D029721:Drosophila Proteins; D051638:Ether-A-Go-Go Potassium Channels; D008565:Membrane Proteins; D011994:Recombinant Proteins; C496883:eag protein, Drosophila; D011188:Potassium