title: Distribution of the SynDIG4/proline-rich transmembrane protein 1 in rat brain.
abstract: The modulation of AMPA receptor (AMPAR) content at synapses is thought to be an underlying molecular mechanism of memory and learning. AMPAR content at synapses is highly plastic and is regulated by numerous AMPAR accessory transmembrane proteins such as TARPs, cornichons, and CKAMPs. SynDIG (synapse differentiation-induced gene) defines a family of four genes (SynDIG1-4) expressed in distinct and overlapping patterns in the brain. SynDIG1 was previously identified as a novel transmembrane AMPAR-associated protein that regulates synaptic strength. The related protein SynDIG4 [also known as Prrt1 (proline-rich transmembrane protein 1)] has recently been identified as a component of AMPAR complexes. In this study, we show that SynDIG1 and SynDIG4 have distinct yet overlapping patterns of expression in the central nervous system, with SynDIG4 having especially prominent expression in the hippocampus and particularly within CA1. In contrast to SynDIG1 and other traditional AMPAR auxiliary subunits, SynDIG4 is de-enriched at the postsynaptic density and colocalizes with extrasynaptic GluA1 puncta in primary dissociated neuron culture. These results indicate that, although SynDIG4 shares sequence similarity with SynDIG1, it might act through a unique mechanism as an auxiliary factor for extrasynaptic GluA1-containing AMPARs. J. Comp. Neurol. 524:2266-2280, 2016. © 2015 Wiley Periodicals, Inc.
authors.affiliation: Department of Pharmacology, University of California Davis School of Medicine, Davis, California, 95616.
authors.forename: Lyndsey M
authors.initials: LM
authors.lastname: Kirk
authors.affiliation: Department of Neurobiology, Physiology and Behavior, University of California, Davis, California, 95616.
authors.forename: Shu W
authors.initials: SW
authors.lastname: Ti
authors.affiliation: Department of Neurobiology, Physiology and Behavior, University of California, Davis, California, 95616.
authors.forename: Hannah I
authors.initials: HI
authors.lastname: Bishop
authors.affiliation: Department of Pharmacology, University of California Davis School of Medicine, Davis, California, 95616.
authors.forename: Mayra
authors.initials: M
authors.lastname: Orozco-Llamas
authors.affiliation: Department of Pharmacology, University of California Davis School of Medicine, Davis, California, 95616.
authors.forename: Michelle
authors.initials: M
authors.lastname: Pham
authors.affiliation: Department of Neurobiology, Physiology and Behavior, University of California, Davis, California, 95616.|Department of Physiology and Membrane Biology, University of California Davis School of Medicine, Davis, California, 95616.
authors.forename: James S
authors.initials: JS
authors.lastname: Trimmer
authors.affiliation: Department of Pharmacology, University of California Davis School of Medicine, Davis, California, 95616.
authors.forename: Elva
authors.initials: E
authors.lastname: Díaz
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism*; D015151:Immunoblotting; D007150:Immunohistochemistry; D008565:Membrane Proteins / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D018091:Receptors, AMPA / Q000378:metabolism
chemical_list: D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D018091:Receptors, AMPA
keywords: AMPA receptor; Prrt1; RRID:AB_10999753; RRID:AB_2113602; RRID:AB_2232661; RRID:AB_2277296; RRID:AB_2301751; RRID:AB_2307331; RRID:AB_2491106; RRID:AB_309885; RRID:AB_390919; RRID:AB_887824; RRID:RGD_70508; RRID:SCR_013715; RRID:ScrRes_000161; RRID:nif-0000-30467; SynDIG4; auxiliary factor; excitatory synapse; rat brain; synapse differentiation-induced gene (SynDIG) family