title: Dynamic NHERF interaction with TRPC4/5 proteins is required for channel gating by diacylglycerol.
abstract: The activation mechanism of the classical transient receptor potential channels TRPC4 and -5 via the Gq/11protein-phospholipase C (PLC) signaling pathway has remained elusive so far. In contrast to all other TRPC channels, the PLC product diacylglycerol (DAG) is not sufficient for channel activation, whereas TRPC4/5 channel activity is potentiated by phosphatidylinositol 4,5-bisphosphate (PIP2) depletion. As a characteristic structural feature, TRPC4/5 channels contain a C-terminal PDZ-binding motif allowing for binding of the scaffolding proteins Na+/H+exchanger regulatory factor (NHERF) 1 and 2. PKC inhibition or the exchange of threonine for alanine in the C-terminal PDZ-binding motif conferred DAG sensitivity to the channel. Altogether, we present a DAG-mediated activation mechanism for TRPC4/5 channels tightly regulated by NHERF1/2 interaction. PIP2depletion evokes a C-terminal conformational change of TRPC5 proteins leading to dynamic dissociation of NHERF1/2 from the C terminus of TRPC5 as a prerequisite for DAG sensitivity. We show that NHERF proteins are direct regulators of ion channel activity and that DAG sensitivity is a distinctive hallmark of TRPC channels.
authors.affiliation: Walther Straub Institute of Pharmacology and Toxicology, Ludwig Maximilian University of Munich, 80336 Munich, Germany.
authors.forename: Ursula
authors.initials: U
authors.lastname: Storch
authors.affiliation: Walther Straub Institute of Pharmacology and Toxicology, Ludwig Maximilian University of Munich, 80336 Munich, Germany.
authors.forename: Anna-Lena
authors.initials: AL
authors.lastname: Forst
authors.affiliation: Walther Straub Institute of Pharmacology and Toxicology, Ludwig Maximilian University of Munich, 80336 Munich, Germany.
authors.forename: Franziska
authors.initials: F
authors.lastname: Pardatscher
authors.affiliation: Walther Straub Institute of Pharmacology and Toxicology, Ludwig Maximilian University of Munich, 80336 Munich, Germany.
authors.forename: Serap
authors.initials: S
authors.lastname: Erdogmus
authors.affiliation: Walther Straub Institute of Pharmacology and Toxicology, Ludwig Maximilian University of Munich, 80336 Munich, Germany.
authors.forename: Maximilian
authors.initials: M
authors.lastname: Philipp
authors.affiliation: Walther Straub Institute of Pharmacology and Toxicology, Ludwig Maximilian University of Munich, 80336 Munich, Germany.
authors.forename: Manuel
authors.initials: M
authors.lastname: Gregoritza
authors.affiliation: Walther Straub Institute of Pharmacology and Toxicology, Ludwig Maximilian University of Munich, 80336 Munich, Germany; mederos@lrz.uni-muenchen.de.|German Centre for Cardiovascular Research, Munich Heart Alliance, 80802 Munich, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Mederos Y Schnitzler
authors.affiliation: Walther Straub Institute of Pharmacology and Toxicology, Ludwig Maximilian University of Munich, 80336 Munich, Germany.|German Centre for Cardiovascular Research, Munich Heart Alliance, 80802 Munich, Germany.|Comprehensive Pneumology Center Munich, German Center for Lung Research, 81377 Munich, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Gudermann
mesh_terms: D000818:Animals; D016466:CHO Cells; D002460:Cell Line; D003412:Cricetulus; D004075:Diglycerides / Q000378:metabolism*; D004789:Enzyme Activation / Q000502:physiology; D057809:HEK293 Cells; D006801:Humans; D019269:Phosphatidylinositol 4,5-Diphosphate / Q000378:metabolism*; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics; D017923:Sodium-Hydrogen Exchangers / Q000235:genetics / Q000378:metabolism*; D050052:TRPC Cation Channels / Q000378:metabolism*; D010738:Type C Phospholipases / Q000378:metabolism*
chemical_list: C011439:1,2-diacylglycerol; D004075:Diglycerides; D019269:Phosphatidylinositol 4,5-Diphosphate; D010750:Phosphoproteins; D034741:RNA, Small Interfering; D017923:Sodium-Hydrogen Exchangers; D050052:TRPC Cation Channels; C489571:TRPC4 ion channel; C491780:TRPC5 protein, human; C093376:sodium-hydrogen exchanger regulatory factor; D010738:Type C Phospholipases
keywords: NHERF; PIP2 depletion; TRPC; diacylglycerol; protein interaction