title: Acid-sensing ion channel (ASIC) 1a undergoes a height transition in response to acidification.
abstract: 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.
authors.affiliation: Department of Micro Engineering, Graduate School of Engineering, Kyoto University, Sakyo-ku, Kyoto, Japan.
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Yokokawa
authors.forename: Stewart M
authors.initials: SM
authors.lastname: Carnally
authors.forename: Robert M
authors.initials: RM
authors.lastname: Henderson
authors.forename: Kunio
authors.initials: K
authors.lastname: Takeyasu
authors.forename: J Michael
authors.initials: JM
authors.lastname: Edwardson
mesh_terms: D000143:Acids; D002460:Cell Line; D006801:Humans; D007473:Ion Channels / Q000378:metabolism*; D007668:Kidney / Q000166:cytology; D010829:Physiological Phenomena; D014162:Transfection
chemical_list: D000143:Acids; D007473:Ion Channels