title: Fluorescence resonance energy transfer analysis of subunit assembly of the ASIC channel.
abstract: Acid-sensing ion channels (ASICs) are believed to be homo- or heteromeric complexes, which have been verified by classical methods such as co-immunoprecipitation or electrophysiological assays. However, the exact subunit combinations of ASICs in living cells have not been established yet. Here, we apply assays based on fluorescence resonance energy transfer (FRET) between GFP color mutants CFP and YFP to investigate ASIC assembly directly in living cells. Homomerization as well as heteromerization of different combinations of ASIC subunits were found. In addition, our results suggest the formation of heteromeric 1a/2a channels of stoichiometry consisting of at least two 1a subunits and two 2a subunits. Similar stoichiometry was observed from heteromeric 1a/2b and 2a/2b channels. Our results imply that these heteromeric ASIC channels contain at least four subunits.
authors.affiliation: Department of Neurobiology, Institute for Neuroscience, Zhejiang University School of Medicine, Hangzhou 310058, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Gao
authors.forename: Shuang-Shuang
authors.initials: SS
authors.lastname: Liu
authors.forename: Shuang
authors.initials: S
authors.lastname: Qiu
authors.forename: Wei
authors.initials: W
authors.lastname: Cheng
authors.forename: Jie
authors.initials: J
authors.lastname: Zheng
authors.forename: Jian-Hong
authors.initials: JH
authors.lastname: Luo
mesh_terms: D062565:Acid Sensing Ion Channels; D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods*; D008565:Membrane Proteins / Q000737:chemistry* / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000737:chemistry* / Q000378:metabolism*; D021122:Protein Subunits; D015222:Sodium Channels / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D062565:Acid Sensing Ion Channels; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D021122:Protein Subunits; D015222:Sodium Channels