title: 5-HT2A receptor signalling through phospholipase D1 associated with its C-terminal tail.
abstract: The 5-HT2AR (5-hydroxytryptamine-2A receptor) is a GPCR (G-protein-coupled receptor) that is implicated in the actions of hallucinogens and represents a major target of atypical antipsychotic agents. In addition to its classical signalling though PLC (phospholipase C), the receptor can activate several other pathways, including ARF (ADP-ribosylation factor)-dependent activation of PLD (phospholipase D), which appears to be achieved through a mechanism independent of heterotrimeric G-proteins. In the present study we show that wild-type and inactive constructs of PLD1 (but not PLD2) respectively facilitate and inhibit ARF-dependent PLD signalling by the 5-HT2AR. Furthermore we demonstrate that PLD1 specifically co-immunoprecipitates with the receptor and binds to a distal site in GST (glutathione transferase) fusion protein constructs of its C-terminal tail which is distinct from the ARF-interaction site, thereby suggesting the existence of a functional ARF-PLD signalling complex directly associated with this receptor. This reveals the spatial co-ordination of an important GPCR, transducer and effector into a physical complex that is likely to reinforce the impact of receptor activation on a heterotrimeric G-protein-independent signalling pathway. Signalling of this receptor through such non-canonical pathways may be important to its role in particular disorders.
authors.affiliation: Centre for Integrative Physiology, School of Biomedical Sciences, Hugh Robson Building, University of Edinburgh, Edinburgh EH8 9XD, UK.
authors.forename: Zoë
authors.initials: Z
authors.lastname: Barclay
authors.forename: Louise
authors.initials: L
authors.lastname: Dickson
authors.forename: Derek N
authors.initials: DN
authors.lastname: Robertson
authors.forename: Melanie S
authors.initials: MS
authors.lastname: Johnson
authors.forename: Pamela J
authors.initials: PJ
authors.lastname: Holland
authors.forename: Roberta
authors.initials: R
authors.lastname: Rosie
authors.forename: Liting
authors.initials: L
authors.lastname: Sun
authors.forename: Sue
authors.initials: S
authors.lastname: Fleetwood-Walker
authors.forename: Eve M
authors.initials: EM
authors.lastname: Lutz
authors.forename: Rory
authors.initials: R
authors.lastname: Mitchell
mesh_terms: D020727:ADP-Ribosylation Factors / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D019556:COS Cells; D002522:Chlorocebus aethiops; D010739:Phospholipase D / Q000737:chemistry / Q000502:physiology*; D044402:Receptor, Serotonin, 5-HT2A / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology*
chemical_list: D044402:Receptor, Serotonin, 5-HT2A; D010739:Phospholipase D; C106801:phospholipase D1; D020727:ADP-Ribosylation Factors