title: 14-3-3 Proteins regulate K2P5.1 surface expression on T lymphocytes.
abstract: K2P5.1 channels (also called TASK-2 or Kcnk5) have already been shown to be relevant in the pathophysiology of autoimmune disease because they are known to be upregulated on peripheral and central T lymphocytes of multiple sclerosis (MS) patients. Moreover, overexpression of K2P5.1 channels in vitro provokes enhanced T-cell effector functions. However, the molecular mechanisms regulating intracellular K2P5.1 channel trafficking are unknown so far. Thus, the aim of the study is to elucidate the trafficking of K2P5.1 channels on T lymphocytes. Using mass spectrometry analysis, we have identified 14-3-3 proteins as novel binding partners of K2P5.1 channels. We show that a non-classical 14-3-3 consensus motif (R-X-X-pT/S-x) at the channel's C-terminus allows the binding between K2P5.1 and 14-3-3. The mutant K2P5.1/S266A diminishes the protein-protein interaction and reduces the amplitude of membrane currents. Application of a non-peptidic 14-3-3 inhibitor (BV02) significantly reduces the number of wild-type channels in the plasma membrane, whereas the drug has no effect on the trafficking of the mutated channel. Furthermore, blocker application reduces T-cell effector functions. Taken together, we demonstrate that 14-3-3 interacts with K2P5.1 and plays an important role in channel trafficking.
authors.affiliation: Department of Neurology, Westfälische Wilhelms-Universität, Münster, Germany.
authors.forename: Juncal
authors.initials: J
authors.lastname: Fernández-Orth
authors.affiliation: Department of Neurology, Westfälische Wilhelms-Universität, Münster, Germany.
authors.forename: Petra
authors.initials: P
authors.lastname: Ehling
authors.affiliation: Department of Neurology, Westfälische Wilhelms-Universität, Münster, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Ruck
authors.affiliation: Department of Neurology, Westfälische Wilhelms-Universität, Münster, Germany.
authors.forename: Susann
authors.initials: S
authors.lastname: Pankratz
authors.affiliation: Department of Neurology, Westfälische Wilhelms-Universität, Münster, Germany.
authors.forename: Majella-Sophie
authors.initials: MS
authors.lastname: Hofmann
authors.affiliation: Neural Plasticity and Communication, Institute for Pharmacology and Toxicology, Otto von-Guericke-University, Magdeburg, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Landgraf
authors.affiliation: Neural Plasticity and Communication, Institute for Pharmacology and Toxicology, Otto von-Guericke-University, Magdeburg, Germany.|Center for Behavioral Brain Sciences (CBBS), Otto von-Guericke-University, Magdeburg, Germany.
authors.forename: Daniela C
authors.initials: DC
authors.lastname: Dieterich
authors.affiliation: Special Lab Molecular Biological Techniques, Leibniz Institute for Neurobiology, Magdeburg, Germany.
authors.forename: Karl-Heinz
authors.initials: KH
authors.lastname: Smalla
authors.affiliation: Institute of Experimental Internal Medicine, Medical Faculty, Otto-von-Guericke-University, Magdeburg, Germany.
authors.forename: Thilo
authors.initials: T
authors.lastname: Kähne
authors.affiliation: Department of Cardiovascular Medicine, Institute for Genetics of Heart Diseases (IfGH), University Hospital Münster, Münster, Germany.
authors.forename: Guiscard
authors.initials: G
authors.lastname: Seebohm
authors.affiliation: Institute for Physiology I, Westfälische Wilhelms-Universität, Münster, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Budde
authors.affiliation: Department of Neurology, Westfälische Wilhelms-Universität, Münster, Germany.
authors.forename: Heinz
authors.initials: H
authors.lastname: Wiendl
authors.affiliation: Department of Neurology, University Medical Center, Johannes Gutenberg-University, Mainz, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Bittner
authors.affiliation: Department of Neurology, Westfälische Wilhelms-Universität, Münster, Germany.
authors.forename: Sven G
authors.initials: SG
authors.lastname: Meuth
mesh_terms: D048948:14-3-3 Proteins / Q000378:metabolism*; D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D005260:Female; D057809:HEK293 Cells; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D024683:Potassium Channels, Tandem Pore Domain / Q000378:metabolism*; D021381:Protein Transport / Q000502:physiology; D013601:T-Lymphocytes / Q000378:metabolism*; D015854:Up-Regulation / Q000502:physiology
chemical_list: D048948:14-3-3 Proteins; D024683:Potassium Channels, Tandem Pore Domain
keywords: 14-3-3; K2P5.1; T-cells; membrane trafficking; multiple sclerosis