title: Exploration of the Peptide Recognition of an Amiloride-sensitive FMRFamide Peptide-gated Sodium Channel.
abstract: FMRFamide (Phe-Met-Arg-Phe-NH2)-activated sodium channel (FaNaC) is an amiloride-sensitive sodium channel activated by endogenous tetrapeptide in invertebrates, and belongs to the epithelial sodium channel/degenerin (ENaC/DEG) superfamily. The ENaC/DEG superfamily differs markedly in its means of activation, such as spontaneously opening or gating by mechanical stimuli or tissue acidosis. Recently, it has been observed that a number of ENaC/DEG channels can be activated by small molecules or peptides, indicating that the ligand-gating may be an important feature of this superfamily. The peptide ligand control of the channel gating might be an ancient ligand-gating feature in this superfamily. Therefore, studying the peptide recognition of FaNaC channels would advance our understanding of the ligand-gating properties of this superfamily of ion channels. Here we demonstrate that Tyr-131, Asn-134, Asp-154, and Ile-160, located in the putative upper finger domain ofHelix aspersaFaNaC (HaFaNaC) channels, are key residues for peptide recognition of this ion channel. Two HaFaNaC specific-insertion motifs among the ENaC/DEG superfamily, residing at the putative α4-α5 linker of the upper thumb domain and the α6-α7 linker of the upper knuckle domain, are also essential for the peptide recognition of HaFaNaC channels. Chemical modifications and double mutant cycle analysis further indicated that those two specific inserts and key residues in the upper finger domain together participate in peptide recognition of HaFaNaC channels. This ligand recognition site is distinct from that of acid-sensing ion channels (ASICs) by a longer distance between the recognition site and the channel gate, carrying useful information about the ligand gating and the evolution of the trimeric ENaC/DEG superfamily of ion channels.
authors: From the College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, 410128, China, Institute of Medical Sciences and Departments of Pharmacology and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.
authors: You-Ya
authors: YY
authors: Niu
authors: Institute of Medical Sciences and Departments of Pharmacology and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.
authors: Yang
authors: Y
authors: Yang
authors: Institute of Medical Sciences and Departments of Pharmacology and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.
authors: Yan
authors: Y
authors: Liu
authors: Institute of Medical Sciences and Departments of Pharmacology and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.
authors: Li-Dong
authors: LD
authors: Huang
authors: From the College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, 410128, China, Institute of Medical Sciences and Departments of Pharmacology and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.
authors: Xiao-Na
authors: XN
authors: Yang
authors: Putuo District Center Hospital, Shanghai University of Chinese Traditional Medicine, Shanghai, 200062, China.
authors: Ying-Zhe
authors: YZ
authors: Fan
authors: Institute of Medical Sciences and Departments of Pharmacology and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.
authors: Xiao-Yang
authors: XY
authors: Cheng
authors: Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing 210023, China, and Laboratory of Cellular and Molecular Biology, Jiangsu Province Academy of Traditional Chinese Medicine, Nanjing 210028, China.
authors: Peng
authors: P
authors: Cao
authors: Institute of Medical Sciences and Departments of Pharmacology and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.
authors: You-Min
authors: YM
authors: Hu
authors: Department of Anesthesiology and Perioperative Medicine, University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030.
authors: Lingyong
authors: L
authors: Li
authors: From the College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, 410128, China.
authors: Xiang-Yang
authors: XY
authors: Lu
authors: From the College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, 410128, China, tianyun79616@163.com.
authors: Yun
authors: Y
authors: Tian
authors: From the College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, 410128, China, Institute of Medical Sciences and Departments of Pharmacology and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China, yuye@shsmu.edu.cn.
authors: Ye
authors: Y
authors: Yu
mesh_terms: D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D057809:HEK293 Cells; D006801:Humans; D015640:Ion Channel Gating / Q000502:physiology*; D010455:Peptides / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D015222:Sodium Channels / Q000235:genetics / Q000378:metabolism*
chemical_list: C097095:FaNaCh protein, Helix aspersa; D010455:Peptides; D015222:Sodium Channels
keywords: FMRFamide (Phe-Met-Arg-Phe-NH2) peptides; FaNaC channels; channel gating; epithelial sodium channel (ENaC); ion channel; ligand-binding protein; ligand-recognition; neuropeptide; peptide interaction