title: Molecular Determinants of Kv1.3 Potassium Channels-induced Proliferation.
abstract: Changes in voltage-dependent potassium channels (Kv channels) associate to proliferation in many cell types, including transfected HEK293 cells. In this system Kv1.5 overexpression decreases proliferation, whereas Kv1.3 expression increases it independently of K(+) fluxes. To identify Kv1.3 domains involved in a proliferation-associated signaling mechanism(s), we constructed chimeric Kv1.3-Kv1.5 channels and point-mutant Kv1.3 channels, which were expressed as GFP- or cherry-fusion proteins. We studied their trafficking and functional expression, combining immunocytochemical and electrophysiological methods, and their impact on cell proliferation. We found that the C terminus is necessary for Kv1.3-induced proliferation. We distinguished two residues (Tyr-447 and Ser-459) whose mutation to alanine abolished proliferation. The insertion into Kv1.5 of a sequence comprising these two residues increased proliferation rate. Moreover, Kv1.3 voltage-dependent transitions from closed to open conformation induced MEK-ERK1/2-dependent Tyr-447 phosphorylation. We conclude that the mechanisms for Kv1.3-induced proliferation involve the accessibility of key docking sites at the C terminus. For one of these sites (Tyr-447) we demonstrated the contribution of MEK/ERK-dependent phosphorylation, which is regulated by voltage-induced conformational changes.
authors.affiliation: From the Departamento de Bioquímica y Biología Molecular y Fisiología e Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid y Consejo Superior de Investigaciones Científicas (CSIC), 47003 Valladolid, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Jiménez-Pérez
authors.affiliation: From the Departamento de Bioquímica y Biología Molecular y Fisiología e Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid y Consejo Superior de Investigaciones Científicas (CSIC), 47003 Valladolid, Spain.
authors.forename: Pilar
authors.initials: P
authors.lastname: Cidad
authors.affiliation: From the Departamento de Bioquímica y Biología Molecular y Fisiología e Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid y Consejo Superior de Investigaciones Científicas (CSIC), 47003 Valladolid, Spain.
authors.forename: Inés
authors.initials: I
authors.lastname: Álvarez-Miguel
authors.affiliation: From the Departamento de Bioquímica y Biología Molecular y Fisiología e Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid y Consejo Superior de Investigaciones Científicas (CSIC), 47003 Valladolid, Spain.
authors.forename: Alba
authors.initials: A
authors.lastname: Santos-Hipólito
authors.affiliation: From the Departamento de Bioquímica y Biología Molecular y Fisiología e Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid y Consejo Superior de Investigaciones Científicas (CSIC), 47003 Valladolid, Spain.
authors.forename: Rebeca
authors.initials: R
authors.lastname: Torres-Merino
authors.affiliation: From the Departamento de Bioquímica y Biología Molecular y Fisiología e Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid y Consejo Superior de Investigaciones Científicas (CSIC), 47003 Valladolid, Spain.
authors.forename: Esperanza
authors.initials: E
authors.lastname: Alonso
authors.affiliation: From the Departamento de Bioquímica y Biología Molecular y Fisiología e Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid y Consejo Superior de Investigaciones Científicas (CSIC), 47003 Valladolid, Spain.
authors.forename: Miguel Ángel
authors.initials: MÁ
authors.lastname: de la Fuente
authors.affiliation: From the Departamento de Bioquímica y Biología Molecular y Fisiología e Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid y Consejo Superior de Investigaciones Científicas (CSIC), 47003 Valladolid, Spain.
authors.forename: José Ramón
authors.initials: JR
authors.lastname: López-López
authors.affiliation: From the Departamento de Bioquímica y Biología Molecular y Fisiología e Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid y Consejo Superior de Investigaciones Científicas (CSIC), 47003 Valladolid, Spain tperez@ibgm.uva.es.
authors.forename: M Teresa
authors.identifier: http://orcid.org/0000-0001-8540-8117
authors.initials: MT
authors.lastname: Pérez-García
mesh_terms: D019943:Amino Acid Substitution; D049109:Cell Proliferation; D057809:HEK293 Cells; D006801:Humans; D051664:Kv1.3 Potassium Channel / Q000819:agonists* / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D051666:Kv1.5 Potassium Channel / Q000819:agonists / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D048369:MAP Kinase Kinase 1 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D048370:MAP Kinase Kinase 2 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D020935:MAP Kinase Signaling System; D016254:Mutagenesis, Insertional; D010446:Peptide Fragments / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation; D017354:Point Mutation; D011487:Protein Conformation; D054730:Protein Interaction Domains and Motifs; D011499:Protein Processing, Post-Translational; D021381:Protein Transport; D034622:RNA Interference; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D014443:Tyrosine / Q000378:metabolism
chemical_list: C496973:KCNA3 protein, human; C496981:KCNA5 protein, human; D051664:Kv1.3 Potassium Channel; D051666:Kv1.5 Potassium Channel; D008164:Luminescent Proteins; D010446:Peptide Fragments; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D014443:Tyrosine; C482128:MAP2K2 protein, human; D048369:MAP Kinase Kinase 1; D048370:MAP Kinase Kinase 2; C482125:MAP2K1 protein, human
keywords: Kv1.3; cell proliferation; electrophysiology; membrane potential; mutagenesis; potassium channel; structure-function; tyrosine phosphorylation; voltage-dependent conformation