title: K2P channel gating mechanisms revealed by structures of TREK-2 and a complex with Prozac.
abstract: TREK-2 (KCNK10/K2P10), a two-pore domain potassium (K2P) channel, is gated by multiple stimuli such as stretch, fatty acids, and pH and by several drugs. However, the mechanisms that control channel gating are unclear. Here we present crystal structures of the human TREK-2 channel (up to 3.4 angstrom resolution) in two conformations and in complex with norfluoxetine, the active metabolite of fluoxetine (Prozac) and a state-dependent blocker of TREK channels. Norfluoxetine binds within intramembrane fenestrations found in only one of these two conformations. Channel activation by arachidonic acid and mechanical stretch involves conversion between these states through movement of the pore-lining helices. These results provide an explanation for TREK channel mechanosensitivity, regulation by diverse stimuli, and possible off-target effects of the serotonin reuptake inhibitor Prozac.
authors.affiliation: Structural Genomics Consortium, University of Oxford, Oxford OX3 7DQ, UK.
authors.forename: Yin Yao
authors.initials: YY
authors.lastname: Dong
authors.affiliation: Structural Genomics Consortium, University of Oxford, Oxford OX3 7DQ, UK.
authors.forename: Ashley C W
authors.initials: AC
authors.lastname: Pike
authors.affiliation: Structural Genomics Consortium, University of Oxford, Oxford OX3 7DQ, UK. Clarendon Laboratory, Department of Physics, University of Oxford, Oxford OX1 3PU, UK.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Mackenzie
authors.affiliation: Clarendon Laboratory, Department of Physics, University of Oxford, Oxford OX1 3PU, UK. OXION Initiative in Ion Channels and Disease, University of Oxford, Oxford OX1 3PN, UK.
authors.forename: Conor
authors.initials: C
authors.lastname: McClenaghan
authors.affiliation: Clarendon Laboratory, Department of Physics, University of Oxford, Oxford OX1 3PU, UK. OXION Initiative in Ion Channels and Disease, University of Oxford, Oxford OX1 3PN, UK. Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK.
authors.forename: Prafulla
authors.initials: P
authors.lastname: Aryal
authors.affiliation: Structural Genomics Consortium, University of Oxford, Oxford OX3 7DQ, UK.
authors.forename: Liang
authors.initials: L
authors.lastname: Dong
authors.affiliation: Structural Genomics Consortium, University of Oxford, Oxford OX3 7DQ, UK.
authors.forename: Andrew
authors.initials: A
authors.lastname: Quigley
authors.affiliation: Structural Genomics Consortium, University of Oxford, Oxford OX3 7DQ, UK.
authors.forename: Mariana
authors.initials: M
authors.lastname: Grieben
authors.affiliation: Structural Genomics Consortium, University of Oxford, Oxford OX3 7DQ, UK.
authors.forename: Solenne
authors.initials: S
authors.lastname: Goubin
authors.affiliation: Structural Genomics Consortium, University of Oxford, Oxford OX3 7DQ, UK.
authors.forename: Shubhashish
authors.initials: S
authors.lastname: Mukhopadhyay
authors.affiliation: Structural Genomics Consortium, University of Oxford, Oxford OX3 7DQ, UK. Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford OX3 7FZ, UK.
authors.forename: Gian Filippo
authors.initials: GF
authors.lastname: Ruda
authors.affiliation: Clarendon Laboratory, Department of Physics, University of Oxford, Oxford OX1 3PU, UK.
authors.forename: Michael V
authors.initials: MV
authors.lastname: Clausen
authors.affiliation: Pfizer Neusentis, Granta Park, Cambridge CB21 6GS, UK.
authors.forename: Lishuang
authors.initials: L
authors.lastname: Cao
authors.affiliation: Structural Genomics Consortium, University of Oxford, Oxford OX3 7DQ, UK. Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford OX3 7FZ, UK.
authors.forename: Paul E
authors.initials: PE
authors.lastname: Brennan
authors.affiliation: Structural Genomics Consortium, University of Oxford, Oxford OX3 7DQ, UK.
authors.forename: Nicola A
authors.initials: NA
authors.lastname: Burgess-Brown
authors.affiliation: OXION Initiative in Ion Channels and Disease, University of Oxford, Oxford OX1 3PN, UK. Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK.
authors.forename: Mark S P
authors.initials: MS
authors.lastname: Sansom
authors.affiliation: Clarendon Laboratory, Department of Physics, University of Oxford, Oxford OX1 3PU, UK. OXION Initiative in Ion Channels and Disease, University of Oxford, Oxford OX1 3PN, UK. liz.carpenter@sgc.ox.ac.uk stephen.tucker@physics.ox.ac.uk.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Tucker
authors.affiliation: Structural Genomics Consortium, University of Oxford, Oxford OX3 7DQ, UK. OXION Initiative in Ion Channels and Disease, University of Oxford, Oxford OX1 3PN, UK. liz.carpenter@sgc.ox.ac.uk stephen.tucker@physics.ox.ac.uk.
authors.forename: Elisabeth P
authors.initials: EP
authors.lastname: Carpenter
mesh_terms: D000595:Amino Acid Sequence; D016718:Arachidonic Acid / Q000494:pharmacology; D001665:Binding Sites; D018360:Crystallography, X-Ray; D005473:Fluoxetine / Q000031:analogs & derivatives / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D006801:Humans; D015640:Ion Channel Gating; D008958:Models, Molecular; D056004:Molecular Dynamics Simulation; D008969:Molecular Sequence Data; D011188:Potassium / Q000378:metabolism; D024683:Potassium Channels, Tandem Pore Domain / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000378:metabolism; D011487:Protein Conformation; D017510:Protein Folding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary
chemical_list: C503438:KCNK10 protein, human; D024683:Potassium Channels, Tandem Pore Domain; D005473:Fluoxetine; D016718:Arachidonic Acid; C036139:norfluoxetine; D011188:Potassium