RT Journal Article
SR Electronic
T1 The intracellular N-terminus domain of the acid-sensing ion channel 1a participates in channel opening and membrane expression
JF Molecular Pharmacology
JO Mol Pharmacol
FD American Society for Pharmacology and Experimental Therapeutics
SP MOLPHARM-AR-2020-000153
DO 10.1124/molpharm.120.000153
A1 Wen Li
A1 Xiaomu Wang
A1 Xiandong Meng
A1 Dong Wei
YR 2021
UL http://molpharm.aspetjournals.org/content/early/2021/06/01/molpharm.120.000153.abstract
AB Acid-sensing ion channels (ASICs) are widely expressed in the nervous system. The intracellular C-terminus of ASIC1a has many sites involved in regulating its expression and the opening mechanism, but the role of the intracellular N-terminus domain is poorly understood. Here, we explored the correlation of ASIC1a intracellular N-terminus with membrane expression and gate opening. We modified the N-terminus structure of ASICs by deletion/truncation/mutation strategies and transfected the recombinant plasmids into CHO cells. Protein expression was analyzed with immunofluorescence, western blots, and patch-clamp experiments. Deleting the entire N-terminus decreased the membrane expression of channel proteins, and ion channel opening was lost. Deleting sections of the N-terminus also decreased membrane expression suggested that all areas were significant, with no single or group of amino acid residues playing a decisive role in regulating ASIC1a membrane expression. In terms of gate opening, five amino acid (AA) residues from AA 16 to AA 20 participated in gate opening, and isoleucine at AA 18 was the most important. The whole N-terminus of ASICs participates in the membrane expression of ASIC1a, and five amino acid residues (AA 16 to 20) are involved in the gate opening mechanism. Significance Statement The whole N-terminus of ASICs participates in the membrane expression of ASIC1a, and five amino acid residues (AA 16 to 20) are involved in the gate opening mechanism.