Acid-sensing ion channel (ASIC) 1a undergoes a height transition in response to acidification.
The acid-sensing ion channel (ASIC) 1a is known to assemble as a homotrimer. Here, we used atomic force microscopy to image ASIC1a, integrated into lipid bilayers, at pH 7.0 and pH 6.0. The triangular appearance of the channel was clearly visible. A height distribution for the channels at pH 7.0 had two peaks, at 2 and 4 nm, likely representing the intracellular and extracellular domains, respectively. At pH 6.0 the 2-nm peak remained, but the higher peak shifted to 6 nm. Hence, the extracellular domain of the channel becomes 'taller' after acidification.
Yokokawa
Masatoshi
M
Department of Micro Engineering, Graduate School of Engineering, Kyoto University, Sakyo-ku, Kyoto, Japan.
Carnally
Stewart M
SM
Henderson
Robert M
RM
Takeyasu
Kunio
K
Edwardson
J Michael
JM
D000143:Acids; D002460:Cell Line; D006801:Humans; D007473:Ion Channels / Q000378:metabolism*; D007668:Kidney / Q000166:cytology; D010829:Physiological Phenomena; D014162:Transfection
D000143:Acids; D007473:Ion Channels