title: Conformational changes in the lower palm domain of ASIC1a contribute to desensitization and RFamide modulation.
abstract: Acid-sensing ion channel 1a (ASIC1a) is a proton-gated cation channel that contributes to fear and pain as well as neuronal damage following persistent cerebral acidosis. Neuropeptides can affect acid-induced neuronal injury by altering ASIC1a inactivation and/or steady-state desensitization. Yet, exactly how ASIC1a inactivation and desensitization occur or are modulated by peptides is not completely understood. We found that regions of the extracellular palm domain and the β(11-12) linker are important for inactivation and steady-state desensitization of ASIC1a. The single amino acid substitutions L280C and L415C dramatically enhanced the rate of inactivation and altered the pH-dependence of steady-state desensitization. Further, the use of methanethiosulfonate (MTS) reagents suggests that the lower palm region (L280C) undergoes a conformational change when ASIC1a transitions from closed to desensitized. We determined that L280C also displays an altered response to the RFamide peptide, FRRFamide. Further, the presence of FRRFamide limited MTS modification of L280C. Together, these results indicate a potential role of the lower palm domain in peptide modulation and suggest RFamide-related peptides promote conformational changes within this region. These data provide empirical support for the idea that L280, and likely this region of the central vestibule, is intimately involved in channel inactivation and desensitization.
authors: Department of Neuroscience, Wexner Medical Center, The Ohio State University, Columbus, Ohio, United States of America ; Biomedical Sciences Graduate Program, The Ohio State University, Columbus, Ohio, United States of America.
authors: Erin N
authors: EN
authors: Frey
authors: Ryan E
authors: RE
authors: Pavlovicz
authors: Clem John
authors: CJ
authors: Wegman
authors: Chenglong
authors: C
authors: Li
authors: Candice C
authors: CC
authors: Askwith
mesh_terms: D062565:Acid Sensing Ion Channels / Q000737:chemistry* / Q000378:metabolism*; D000818:Animals; D006801:Humans; D015640:Ion Channel Gating; D008698:Mesylates / Q000378:metabolism; D009154:Mutation; D009479:Neuropeptides / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D013329:Structure-Activity Relationship; D014982:Xenopus laevis
chemical_list: C568266:ASIC1 protein, human; D062565:Acid Sensing Ion Channels; D008698:Mesylates; D009479:Neuropeptides; C416987:RFamide peptide; C074502:methanethiosulfonate
references: Neuropharmacology. 2006 Jun;50(8):964-74
references: 16549075
references: Curr Pharm Des. 2009;15(15):1750-66
references: 19442188
references: J Biol Chem. 2011 Jul 8;286(27):24374-84
references: 21576243
references: J Biol Chem. 2008 Jan 25;283(4):1818-30
references: 17984098
references: J Biol Chem. 2010 Dec 31;285(53):41852-62
references: 21036899
references: EMBO J. 2004 Apr 7;23(7):1516-25
references: 15044953
references: Neuropharmacology. 2003 Apr;44(5):662-71
references: 12668052
references: Brain. 2011 Feb;134(Pt 2):571-84
references: 21233144
references: J Gen Physiol. 2005 Jul;126(1):71-9
references: 15955877
references: Biol Psychiatry. 2007 Nov 15;62(10):1140-8
references: 17662962
references: Peptides. 2006 May;27(5):1138-52
references: 16516345
references: J Biol Chem. 2013 Feb 22;288(8):5487-95
references: 23300086
references: Nature. 1997 Mar 13;386(6621):173-7
references: 9062189
references: J Biol Chem. 2011 Jul 15;286(28):24996-5006
references: 21586569
references: Nature. 2012 Oct 25;490(7421):552-5
references: 23034652
references: J Struct Biol. 2012 Sep;179(3):269-78
references: 21963794
references: J Mol Biol. 1993 Dec 5;234(3):779-815
references: 8254673
references: Proc Natl Acad Sci U S A. 2004 Mar 9;101(10):3621-6
references: 14988500
references: J Comput Chem. 2004 Oct;25(13):1605-12
references: 15264254
references: Nature. 2007 Sep 20;449(7160):316-23
references: 17882215
references: Annu Rev Physiol. 2000;62:573-94
references: 10845103
references: Protein Sci. 2006 Nov;15(11):2507-24
references: 17075131
references: Neuron. 2003 Jan 9;37(1):75-84
references: 12526774
references: Trends Neurosci. 2006 Oct;29(10):578-86
references: 16891000
references: J Biol Chem. 2000 Aug 18;275(33):25116-21
references: 10829030
references: Biochemistry. 1986 Sep 23;25(19):5595-601
references: 3778876
references: Cell Death Differ. 2013 Apr;20(4):589-98
references: 23306556
references: J Neurophysiol. 2003 May;89(5):2459-65
references: 12612000
references: Nat Med. 2007 Dec;13(12):1483-9
references: 17994101
references: J Biol Chem. 2010 Apr 30;285(18):13816-26
references: 20215117
references: Cell. 2004 Sep 17;118(6):687-98
references: 15369669
references: Nat Commun. 2012 Jul 03;3:936
references: 22760635
references: Channels (Austin). 2012 Nov-Dec;6(6):409-13
references: 22990981
references: Nat Neurosci. 2007 Aug;10(8):943-5
references: 17632507
references: Nature. 2012 Sep 20;489(7416):400-5
references: 22842900
references: J Neurosci. 2003 Jul 2;23(13):5496-502
references: 12843249
references: J Biol Chem. 2010 Jul 16;285(29):22706-12
references: 20479002
references: Neuron. 2010 Oct 6;68(1):61-72
references: 20920791
references: J Neurosci. 2009 Nov 11;29(45):14371-80
references: 19906984
references: Proc Natl Acad Sci U S A. 2001 May 22;98(11):6459-63
references: 11353858
references: J Biol Chem. 2002 Nov 1;277(44):41597-603
references: 12198124
references: J Biol Chem. 2010 Oct 8;285(41):31285-91
references: 20675379
references: J Neurochem. 2004 Oct;91(1):252-5
references: 15379905
references: Nat Neurosci. 2008 Jul;11(7):816-22
references: 18536711
references: Brain. 2007 Jan;130(Pt 1):151-8
references: 17114797
references: J Biol Chem. 2012 Oct 19;287(43):36059-70
references: 22948146
references: J Gen Physiol. 2007 Apr;129(4):345-50
references: 17389250
references: Hypertension. 2000 Jan;35(1 Pt 2):443-50
references: 10642339
references: Nature. 2011 Nov 16;479(7373):410-4
references: 22094702
references: Neuron. 2000 Apr;26(1):133-41
references: 10798398
references: J Physiol. 2002 Sep 1;543(Pt 2):521-9
references: 12205186
references: Proteins. 1989;6(3):316-23
references: 2695930
references: Eur J Pain. 2009 Jul;13(6):554-63
references: 18801682
references: Protein Sci. 2000 Sep;9(9):1753-73
references: 11045621
references: J Neurosci. 2008 Dec 17;28(51):13738-41
references: 19091964
references: Neuropharmacology. 2001 Oct;41(5):592-600
references: 11587714
references: J Biol Chem. 2003 Nov 14;278(46):45240-7
references: 12947112
references: Nature. 2009 Jul 30;460(7255):599-604
references: 19641589
references: J Neurophysiol. 2002 Jun;87(6):2835-43
references: 12037186
references: Nat Rev Neurosci. 2013 Jul;14(7):461-71
references: 23783197
references: J Neurosci. 2009 Apr 29;29(17):5381-8
references: 19403806
references: J Gen Physiol. 2006 Feb;127(2):109-17
references: 16418400
references: Genes Brain Behav. 2011 Jun;10(4):444-50
references: 21324060