title: β1-subunit-induced structural rearrangements of the Ca2+- and voltage-activated K+ (BK) channel.
abstract: Large-conductance Ca(2+)- and voltage-activated K(+) (BK) channels are involved in a large variety of physiological processes. Regulatory β-subunits are one of the mechanisms responsible for creating BK channel diversity fundamental to the adequate function of many tissues. However, little is known about the structure of its voltage sensor domain. Here, we present the external architectural details of BK channels using lanthanide-based resonance energy transfer (LRET). We used a genetically encoded lanthanide-binding tag (LBT) to bind terbium as a LRET donor and a fluorophore-labeled iberiotoxin as the LRET acceptor for measurements of distances within the BK channel structure in a living cell. By introducing LBTs in the extracellular region of the α- or β1-subunit, we determined (i) a basic extracellular map of the BK channel, (ii) β1-subunit-induced rearrangements of the voltage sensor in α-subunits, and (iii) the relative position of the β1-subunit within the α/β1-subunit complex.
authors.affiliation: Centro Interdisciplinario de Neurociencias de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaiso 2360103, Chile; Departamento de Biologia, Facultad de Ciencias, Universidad de Chile, Santiago 7800003, Chile;
authors.forename: Juan P
authors.initials: JP
authors.lastname: Castillo
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL 60637; Departamento de Física, Universidad de Guadalajara, Guadalajara, Jalisco, 44430, Mexico;
authors.forename: Jorge E
authors.initials: JE
authors.lastname: Sánchez-Rodríguez
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL 60637;
authors.forename: H Clark
authors.initials: HC
authors.lastname: Hyde
authors.affiliation: Centro Interdisciplinario de Neurociencias de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaiso 2360103, Chile;
authors.forename: Cristian A
authors.initials: CA
authors.lastname: Zaelzer
authors.affiliation: Centro Interdisciplinario de Neurociencias de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaiso 2360103, Chile; Universidad Andrés Bello, Center for Bioinformatics and Integrative Biology, Facultad de Ciencias Biológicas, Santiago 8370146, Chile;
authors.forename: Daniel
authors.initials: D
authors.lastname: Aguayo
authors.affiliation: Universidad Andrés Bello, Center for Bioinformatics and Integrative Biology, Facultad de Ciencias Biológicas, Santiago 8370146, Chile;
authors.forename: Romina V
authors.initials: RV
authors.lastname: Sepúlveda
authors.affiliation: Department of Chemistry, University of Chicago, Chicago, IL 60637.
authors.forename: Louis Y P
authors.initials: LY
authors.lastname: Luk
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL 60637; Department of Chemistry, University of Chicago, Chicago, IL 60637.
authors.forename: Stephen B H
authors.initials: SB
authors.lastname: Kent
authors.affiliation: Centro Interdisciplinario de Neurociencias de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaiso 2360103, Chile; Universidad Andrés Bello, Center for Bioinformatics and Integrative Biology, Facultad de Ciencias Biológicas, Santiago 8370146, Chile;
authors.forename: Fernando D
authors.initials: FD
authors.lastname: Gonzalez-Nilo
authors.affiliation: Centro Interdisciplinario de Neurociencias de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaiso 2360103, Chile; Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL 60637; fbezanilla@uchicago.edu ramon.latorre@uv.cl.
authors.forename: Francisco
authors.initials: F
authors.lastname: Bezanilla
authors.affiliation: Centro Interdisciplinario de Neurociencias de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaiso 2360103, Chile; fbezanilla@uchicago.edu ramon.latorre@uv.cl.
authors.forename: Ramón
authors.initials: R
authors.lastname: Latorre
mesh_terms: D000818:Animals; D004735:Energy Transfer; D005260:Female; D051037:Large-Conductance Calcium-Activated Potassium Channel alpha Subunits / Q000737:chemistry / Q000235:genetics / Q000502:physiology; D051038:Large-Conductance Calcium-Activated Potassium Channel beta Subunits / Q000737:chemistry* / Q000235:genetics / Q000502:physiology; D008958:Models, Molecular; D009865:Oocytes; D011487:Protein Conformation; D000072417:Protein Domains; D014982:Xenopus laevis
chemical_list: D051037:Large-Conductance Calcium-Activated Potassium Channel alpha Subunits; D051038:Large-Conductance Calcium-Activated Potassium Channel beta Subunits
keywords: BK channels; lanthanide resonance energy transfer; β1-subunit