title: Co-Expression of Wild-Type P2X7R with Gln460Arg Variant Alters Receptor Function.
abstract: The P2X7 receptor is a member of the P2X family of ligand-gated ion channels. A single-nucleotide polymorphism leading to a glutamine (Gln) by arginine (Arg) substitution at codon 460 of the purinergic P2X7 receptor (P2X7R) has been associated with mood disorders. No change in function (loss or gain) has been described for this SNP so far. Here we show that although the P2X7R-Gln460Arg variant per se is not compromised in its function, co-expression of wild-type P2X7R with P2X7R-Gln460Arg impairs receptor function with respect to calcium influx, channel currents and intracellular signaling in vitro. Moreover, co-immunoprecipitation and FRET studies show that the P2X7R-Gln460Arg variant physically interacts with P2X7R-WT. Specific silencing of either the normal or polymorphic variant rescues the heterozygous loss of function phenotype and restores normal function. The described loss of function due to co-expression, unique for mutations in the P2RX7 gene so far, explains the mechanism by which the P2X7R-Gln460Arg variant affects the normal function of the channel and may represent a mechanism of action for other mutations.
authors.affiliation: Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA)-CONICET- Partner Institute of the Max Planck Society, Buenos Aires, Argentina.|Departamento de Fisiología y Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.
authors.forename: Fernando
authors.initials: F
authors.lastname: Aprile-Garcia
authors.affiliation: Max Planck Institute of Psychiatry, 80804, Munich, Germany.
authors.forename: Michael W
authors.initials: MW
authors.lastname: Metzger
authors.affiliation: Max Planck Institute of Psychiatry, 80804, Munich, Germany.
authors.forename: Marcelo
authors.initials: M
authors.lastname: Paez-Pereda
authors.affiliation: Affectis Pharmaceuticals, 44227, Dortmund, Germany.
authors.forename: Herbert
authors.initials: H
authors.lastname: Stadler
authors.affiliation: Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA)-CONICET- Partner Institute of the Max Planck Society, Buenos Aires, Argentina.
authors.forename: Matías
authors.initials: M
authors.lastname: Acuña
authors.affiliation: Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA)-CONICET- Partner Institute of the Max Planck Society, Buenos Aires, Argentina.
authors.forename: Ana C
authors.initials: AC
authors.lastname: Liberman
authors.affiliation: Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA)-CONICET- Partner Institute of the Max Planck Society, Buenos Aires, Argentina.
authors.forename: Sergio A
authors.initials: SA
authors.lastname: Senin
authors.affiliation: Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA)-CONICET- Partner Institute of the Max Planck Society, Buenos Aires, Argentina.
authors.forename: Juan
authors.initials: J
authors.lastname: Gerez
authors.affiliation: Centro de Microscopías Avanzadas, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.
authors.forename: Esteban
authors.initials: E
authors.lastname: Hoijman
authors.affiliation: Max Planck Institute of Psychiatry, 80804, Munich, Germany.
authors.forename: Damian
authors.initials: D
authors.lastname: Refojo
authors.affiliation: Max Planck Institute of Experimental Medicine, 37075, Göttingen, Germany.
authors.forename: Mišo
authors.initials: M
authors.lastname: Mitkovski
authors.affiliation: Affectis Pharmaceuticals, 44227, Dortmund, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Panhuysen
authors.affiliation: Max Planck Institute of Experimental Medicine, 37075, Göttingen, Germany.
authors.forename: Walter
authors.initials: W
authors.lastname: Stühmer
authors.affiliation: Max Planck Institute of Psychiatry, 80804, Munich, Germany.|HMNC Brain Health, Munich, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Holsboer
authors.affiliation: Max Planck Institute of Psychiatry, 80804, Munich, Germany.
authors.forename: Jan M
authors.initials: JM
authors.lastname: Deussing
authors.affiliation: Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA)-CONICET- Partner Institute of the Max Planck Society, Buenos Aires, Argentina.|Departamento de Fisiología y Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.|Max Planck Institute of Psychiatry, 80804, Munich, Germany.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Arzt
mesh_terms: D015153:Blotting, Western; D002118:Calcium / Q000378:metabolism / Q000502:physiology; D031541:Fluorescence Resonance Energy Transfer; D057809:HEK293 Cells; D006801:Humans; D047468:Immunoprecipitation; D018408:Patch-Clamp Techniques; D020641:Polymorphism, Single Nucleotide / Q000235:genetics* / Q000502:physiology; D034741:RNA, Small Interfering / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D058486:Receptors, Purinergic P2X7 / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology
chemical_list: C546468:P2RX7 protein, human; D034741:RNA, Small Interfering; D058486:Receptors, Purinergic P2X7; D002118:Calcium