G2Cdb::Gene report

Gene id
Gene symbol
Gria4 (MGI)
Mus musculus
glutamate receptor, ionotropic, AMPA4 (alpha 4)
G00001309 (Homo sapiens)

Databases (8)

ENSMUSG00000025892 (Ensembl mouse gene)
14802 (Entrez Gene)
401 (G2Cdb plasticity & disease)
Gene Expression
NM_019691 (Allen Brain Atlas)
14802 (Genepaint)
138246 (OMIM)
Marker Symbol
MGI:95811 (MGI)
Protein Sequence
Q9Z2W8 (UniProt)

Synonyms (4)

  • Glur-4
  • Glur4
  • Gluralpha4
  • spkw1

Literature (38)

Pubmed - other

  • Glutamate receptor δ2 is essential for input pathway-dependent regulation of synaptic AMPAR contents in cerebellar Purkinje cells.

    Yamasaki M, Miyazaki T, Azechi H, Abe M, Natsume R, Hagiwara T, Aiba A, Mishina M, Sakimura K and Watanabe M

    Department of Anatomy, Hokkaido University Graduate School of Medicine, Sapporo 060-8638, Japan.

    The number of synaptic AMPA receptors (AMPARs) is the major determinant of synaptic strength and is differently regulated in input pathway-dependent and target cell type-dependent manners. In cerebellar Purkinje cells (PCs), the density of synaptic AMPARs is approximately five times lower at parallel fiber (PF) synapses than at climbing fiber (CF) synapses. However, molecular mechanisms underlying this biased synaptic distribution remain unclear. As a candidate molecule, we focused on glutamate receptor δ2 (GluRδ2 or GluD2), which is known to be efficiently trafficked to and selectively expressed at PF synapses in PCs. We applied postembedding immunogold electron microscopy to GluRδ2 knock-out (KO) and control mice, and measured labeling density for GluA1-4 at three excitatory synapses in the cerebellar molecular layer. In both control and GluRδ2-KO mice, GluA1-3 were localized at PF and CF synapses in PCs, while GluA2-4 were at PF synapses in interneurons. In control mice, labeling density for each of GluA1-3 was four to six times lower at PF-PC synapses than at CF-PC synapses. In GluRδ2-KO mice, however, their labeling density displayed a three- to fivefold increase at PF synapses, but not at CF synapses, thus effectively eliminating input pathway-dependent disparity between the two PC synapses. Furthermore, we found an unexpected twofold increase in labeling density for GluA2 and GluA3, but not GluA4, at PF-interneuron synapses, where we identified low but significant expression of GluRδ2. These results suggest that GluRδ2 is involved in a common mechanism that restricts the number of synaptic AMPARs at PF synapses in PCs and molecular layer interneurons.

    The Journal of neuroscience : the official journal of the Society for Neuroscience 2011;31;9;3362-74

  • A high-resolution anatomical atlas of the transcriptome in the mouse embryo.

    Diez-Roux G, Banfi S, Sultan M, Geffers L, Anand S, Rozado D, Magen A, Canidio E, Pagani M, Peluso I, Lin-Marq N, Koch M, Bilio M, Cantiello I, Verde R, De Masi C, Bianchi SA, Cicchini J, Perroud E, Mehmeti S, Dagand E, Schrinner S, Nürnberger A, Schmidt K, Metz K, Zwingmann C, Brieske N, Springer C, Hernandez AM, Herzog S, Grabbe F, Sieverding C, Fischer B, Schrader K, Brockmeyer M, Dettmer S, Helbig C, Alunni V, Battaini MA, Mura C, Henrichsen CN, Garcia-Lopez R, Echevarria D, Puelles E, Garcia-Calero E, Kruse S, Uhr M, Kauck C, Feng G, Milyaev N, Ong CK, Kumar L, Lam M, Semple CA, Gyenesei A, Mundlos S, Radelof U, Lehrach H, Sarmientos P, Reymond A, Davidson DR, Dollé P, Antonarakis SE, Yaspo ML, Martinez S, Baldock RA, Eichele G and Ballabio A

    Telethon Institute of Genetics and Medicine, Naples, Italy.

    Ascertaining when and where genes are expressed is of crucial importance to understanding or predicting the physiological role of genes and proteins and how they interact to form the complex networks that underlie organ development and function. It is, therefore, crucial to determine on a genome-wide level, the spatio-temporal gene expression profiles at cellular resolution. This information is provided by colorimetric RNA in situ hybridization that can elucidate expression of genes in their native context and does so at cellular resolution. We generated what is to our knowledge the first genome-wide transcriptome atlas by RNA in situ hybridization of an entire mammalian organism, the developing mouse at embryonic day 14.5. This digital transcriptome atlas, the Eurexpress atlas (http://www.eurexpress.org), consists of a searchable database of annotated images that can be interactively viewed. We generated anatomy-based expression profiles for over 18,000 coding genes and over 400 microRNAs. We identified 1,002 tissue-specific genes that are a source of novel tissue-specific markers for 37 different anatomical structures. The quality and the resolution of the data revealed novel molecular domains for several developing structures, such as the telencephalon, a novel organization for the hypothalamus, and insight on the Wnt network involved in renal epithelial differentiation during kidney development. The digital transcriptome atlas is a powerful resource to determine co-expression of genes, to identify cell populations and lineages, and to identify functional associations between genes relevant to development and disease.

    Funded by: Medical Research Council: MC_U127527203; Telethon: TGM11S03

    PLoS biology 2011;9;1;e1000582

  • Comprehensive behavioural study of GluR4 knockout mice: implication in cognitive function.

    Sagata N, Iwaki A, Aramaki T, Takao K, Kura S, Tsuzuki T, Kawakami R, Ito I, Kitamura T, Sugiyama H, Miyakawa T and Fukumaki Y

    Division of Human Molecular Genetics, Research Center for Genetic Information, Medical Institute of Bioregulation, Kyushu University, Higashi-ku, Fukuoka, Japan.

    Fast excitatory transmission in the mammalian central nervous system is mediated by AMPA-type glutamate receptors. The tetrameric AMPA receptor complexes are composed of four subunits, GluR1-4. The GluR4 subunit is highly expressed in the cerebellum and the early postnatal hippocampus and is thought to be involved in synaptic plasticity and the development of functional neural circuitry through the recruitment of other AMPA receptor subunits. Previously, we reported an association of the human GluR4 gene (GRIA4) with schizophrenia. To examine the role of the GluR4 subunit in the higher brain function, we generated GluR4 knockout mice and conducted electrophysiological and behavioural analyses. The mutant mice showed normal long-term potentiation (LTP) in the CA1 region of the hippocampus. The GluR4 knockout mice showed mildly improved spatial working memory in the T-maze test. Although the retention of spatial reference memory was intact in the mutant mice, the acquisition of spatial reference memory was impaired in the Barnes circular maze test. The GluR4 knockout mice showed impaired prepulse inhibition. These results suggest the involvement of the GluR4 subunit in cognitive function.

    Genes, brain, and behavior 2010;9;8;899-909

  • Ca2+-dependent release of Munc18-1 from presynaptic mGluRs in short-term facilitation.

    Nakajima Y, Mochida S, Okawa K and Nakanishi S

    Department of Biological Sciences, Faculty of Medicine, Kyoto University, Kyoto, Japan. yoshiaki@phy.med.kyoto-u.ac.jp

    Short-term synaptic facilitation plays an important role in information processing in the central nervous system. Although the crucial requirement of presynaptic Ca(2+) in the expression of this plasticity has been known for decades, the molecular mechanisms underlying the plasticity remain controversial. Here, we show that presynaptic metabotropic glutamate receptors (mGluRs) bind and release Munc18-1 (also known as rbSec1/nSec1), an essential protein for synaptic transmission, in a Ca(2+)-dependent manner, whose actions decrease and increase synaptic vesicle release, respectively. We found that mGluR4 bound Munc18-1 with an EC(50) for Ca(2+) of 168 nM, close to the resting Ca(2+) concentration, and that the interaction was disrupted by Ca(2+)-activated calmodulin (CaM) at higher concentrations of Ca(2+). Consistently, the Munc18-1-interacting domain of mGluR4 suppressed both dense-core vesicle secretion from permeabilized PC12 cells and synaptic transmission in neuronal cells. Furthermore, this domain was sufficient to induce paired-pulse facilitation. Obviously, the role of mGluR4 in these processes was independent of its classical function of activation by glutamate. On the basis of these experimental data, we propose the following model: When neurons are not active, Munc18-1 is sequestered by mGluR4, and therefore the basal synaptic transmission is kept low. After the action potential, the increase in the Ca(2+) level activates CaM, which in turn liberates Munc18-1 from mGluR4, causing short-term synaptic facilitation. Our findings unite and provide a new insight into receptor signaling and vesicular transport, which are pivotal activities involved in a variety of cellular processes.

    Proceedings of the National Academy of Sciences of the United States of America 2009;106;43;18385-9

  • Three-dimensional visualization of testis cord morphogenesis, a novel tubulogenic mechanism in development.

    Combes AN, Lesieur E, Harley VR, Sinclair AH, Little MH, Wilhelm D and Koopman P

    Division of Molecular Genetics and Development, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia.

    Testis cords are specialized tubes essential for generation and export of sperm, yet the mechanisms directing their formation, and the regulation of their position, size, shape, and number remain unclear. Here, we use a novel fluorescence-based three-dimensional modeling approach to show that cords initially form as a network of irregular cell clusters that are subsequently remodeled to form regular parallel loops, joined by a flattened plexus at the mesonephric side. Variation in cord number and structure demonstrates that cord specification is not stereotypic, although cord alignment and diameter becomes relatively consistent, implicating compensatory growth mechanisms. Branched, fused, and internalized cords were commonly observed. We conclude that the tubule-like structure of testis cords arise through a novel form of morphogenesis consisting of coalescence, partitioning, and remodeling. The methods we describe are applicable to investigating defects in testis cord development in mouse models, and more broadly, studying morphogenesis of other tissues.

    Funded by: NIDDK NIH HHS: DK070136, U01 DK070136

    Developmental dynamics : an official publication of the American Association of Anatomists 2009;238;5;1033-41

  • Genetic complexity of absence seizures in substrains of C3H mice.

    Tokuda S, Beyer BJ and Frankel WN

    The Jackson Laboratory, Bar Harbor, ME 04609-1500, USA.

    Absence epilepsy is a common form of idiopathic generalized epilepsy whose etiology is poorly understood because of genetic and phenotypic heterogeneity. The inbred mouse strain C3H/He exhibits spontaneous absence seizures characterized by spike and wave discharges (SWD) on the electroencephalogram concomitant with behavioral arrest. Previous studies using the C3H/HeJ (HeJ) substrain identified a mutation in the Gria4 gene as a major susceptibility locus. In the present study, we found that two closely related substrains C3H/HeOuJ (OuJ) and C3H/HeSnJ, which have a similar SWD incidence as HeJ, do not contain the Gria4 mutation. Further analysis of backcross mice segregating OuJ and C57BL/6J alleles shows that, unlike the HeJ substrain, OuJ does not have a major locus for SWD but has suggestive loci at best that would explain only a fraction of the phenotypic variance. These results illustrate how the genetic etiology of a common neurological disorder can differ between substrains with similar phenotypes. We infer that all C3H strains are sensitized to SWD and that additional mutations affecting SWD arose or were fixed independently in the years since the substrains diverged.

    Funded by: NINDS NIH HHS: NS31348, R01 NS031348, R01 NS031348-16, R37 NS031348

    Genes, brain, and behavior 2009;8;3;283-9

  • Vulnerability of white matter towards antenatal hypoxia is linked to a species-dependent regulation of glutamate receptor subunits.

    Fontaine RH, Olivier P, Massonneau V, Leroux P, Degos V, Lebon S, El Ghouzzi V, Lelièvre V, Gressens P and Baud O

    Institut National de la Santé et de la Recherche Médicale, AVENIR RO5230HS, Paris, France.

    White-matter damage is a leading cause of neurological handicap. Although hypoxia-ischemia and excitotoxicity are major pathogenic factors, a role for genetic influences was suggested recently. Thus, protracted gestational hypoxia was associated with white-matter damage (WMD) in rat pups but not in mouse pups. Indeed, microglial activation and vessel-wall density on postnatal days (P)1 and P10 were found increased in both mouse and rat pups, but cell death, astrogliosis, and myelination were only significantly altered in hypoxic rat pups. We investigated whether this species-related difference was ascribable to effects of antenatal hypoxia on the expression of glutamate receptor subunits by using immunocytochemistry, PCR, and excitotoxic double hit insult. Quantitative PCR in hypoxic mouse pups on P1 showed 2- to 4-fold down-regulation of the AMPA-receptor subunits -1, 2, and -4; of the kainate-receptor subunit GluR7; and of the metabotropic receptor subunits mGluR1, -2, -3, -5, and -7. None of the glutamate-receptor subunits was down-regulated in the hypoxic rat pups. NR2B was the only NMDA-receptor subunit that was down-regulated in hypoxic mice but not in hypoxic rat on P1. Ifenprodil administration to induce functional inhibition of NMDA containing NR2B-subunit receptors prevented hypoxia-induced myelination delay in rat pups. Intracerebral injection of a glutamate agonist produced a larger decrease in ibotenate-induced excitotoxic lesions in hypoxic mouse pups than in normoxic mouse pups. Gestational hypoxia may regulate the expression of specific glutamate-receptor subunits in fetal mice but not in fetal rats. Therefore, genetic factors may influence the susceptibility of rodents to WMD.

    Proceedings of the National Academy of Sciences of the United States of America 2008;105;43;16779-84

  • Absence seizures in C3H/HeJ and knockout mice caused by mutation of the AMPA receptor subunit Gria4.

    Beyer B, Deleuze C, Letts VA, Mahaffey CL, Boumil RM, Lew TA, Huguenard JR and Frankel WN

    The Jackson Laboratory, 600 Main Street, Bar Harbor, ME 04609, USA.

    Absence epilepsy, characterized by spike-wave discharges (SWD) in the electroencephalogram, arises from aberrations within the circuitry of the cerebral cortex and thalamus that regulates awareness. The inbred mouse strain C3H/HeJ is prone to absence seizures, with a major susceptibility locus, spkw1, accounting for most of the phenotype. Here we find that spkw1 is associated with a hypomorphic retroviral-like insertion mutation in the Gria4 gene, encoding one of the four amino-3-hydroxy-5-methyl-4isoxazolepropionic acid (AMPA) receptor subunits in the brain. Consistent with this, Gria4 knockout mice also have frequent SWD and do not complement spkw1. In contrast, null mutants for the related gene Gria3 do not have SWD, and Gria3 loss actually lowers SWD of spkw1 homozygotes. Gria3 and Gria4 encode the predominant AMPA receptor subunits in the reticular thalamus, which is thought to play a central role in seizure genesis by inhibiting thalamic relay cells and promoting rebound burst firing responses. In Gria4 mutants, synaptic excitation of inhibitory reticular thalamic neurons is enhanced, with increased duration of synaptic responses-consistent with what might be expected from reduction of the kinetically faster subunit of AMPA receptors encoded by Gria4. These results demonstrate for the first time an essential role for Gria4 in the brain, and suggest that abnormal AMPA receptor-dependent synaptic activity can be involved in the network hypersynchrony that underlies absence seizures.

    Funded by: NCI NIH HHS: CA34196; NINDS NIH HHS: NS31348, NS32801, NS34744, R37 NS034774

    Human molecular genetics 2008;17;12;1738-49

  • Auditory sensitivity regulation via rapid changes in expression of surface AMPA receptors.

    Chen Z, Kujawa SG and Sewell WF

    Department of Otology and Laryngology, Harvard Medical School, 243 Charles Street, Boston, Massachusetts 02114, USA.

    We report a robust regulation of surface AMPA receptors in mouse auditory neurons, both with application of glutamate receptor agonists in cultured neurons and in response to acoustic stimulation in vivo. The reversible reduction of surface AMPA receptors following acoustic stimulation correlated with changes in acoustic sensitivity. Thus we show that AMPA receptor cycling is important for optimizing synaptic transfer at one of the most exacting synapses in the body.

    Nature neuroscience 2007;10;10;1238-40

  • Recruitment of parvalbumin-positive interneurons determines hippocampal function and associated behavior.

    Fuchs EC, Zivkovic AR, Cunningham MO, Middleton S, Lebeau FE, Bannerman DM, Rozov A, Whittington MA, Traub RD, Rawlins JN and Monyer H

    Department of Clinical Neurobiology, University Hospital of Neurology, IZN, Im Neuenheimer Feld 364, 69120 Heidelberg, Germany.

    Perisomatic inhibition provided by a subgroup of GABAergic interneurons plays a critical role in timing the output of pyramidal cells. To test their contribution at the network and the behavioral level, we generated genetically modified mice in which the excitatory drive was selectively reduced either by the knockout of the GluR-D or by conditional ablation of the GluR-A subunit in parvalbumin-positive cells. Comparable cell type-specific reductions of AMPA-mediated currents were obtained. Kainate-induced gamma oscillations exhibited reduced power in hippocampal slices from GluR-D-/- and GluR-A(PVCre-/-) mice. Experimental and modeling data indicated that this alteration could be accounted for by imprecise spike timing of fast-spiking cells (FS) caused by smaller interneuronal EPSPs. GluR-D-/- and GluR-A(PVCre-/-) mice exhibited similar impairments in hippocampus-dependent tasks. These findings directly show the effects of insufficient recruitment of fast-spiking cells at the network and behavioral level and demonstrate the role of this subpopulation for working and episodic-like memory.

    Funded by: Wellcome Trust: 087736

    Neuron 2007;53;4;591-604

  • Genetic and environmental interactions determine seizure susceptibility in epileptic EL mice.

    Todorova MT, Mantis JG, Le M, Kim CY and Seyfried TN

    Biology Department, Boston College, Chestnut Hill, MA 02467, USA.

    Gene identification has progressed rapidly for monogenic epilepsies, but complex gene-environmental interactions have hindered progress in gene identification for multifactorial epilepsies. We analyzed the role of environmental risk factors in the inheritance of multifactorial idiopathic generalized epilepsy in the EL mouse. Seizure susceptibility was evaluated in the EL (E) and seizure-resistant ABP/LeJ (A) parental mouse strains and in their AEF1 and AEF2 hybrid offspring using a handling-induced seizure test. The seizure test was administered in three environments (environments I, II and III) that differed with respect to the number of seizure tests administered (one test or four tests) and the age of the mice when tested (young or old). The inheritance of seizure susceptibility appeared dominant after repetitive seizure testing in young or old mice, but recessive after a single test in old mice. Heritability was high (0.67-0.77) in each environment. Significant quantitative trait loci (QTL) that were associated with environments I and III (repetitive testing) were found on chromosomes 2 and 9 and colocalized with previously mapped El2 and El4, respectively. The El2 QTL found in environment I associated only with female susceptibility. A novel QTL, El-N, for age-dependent predisposition to seizures was found on proximal chromosome 9 only in environment II. The findings indicate that environmental risk factors determine the genetic architecture of seizure susceptibility in EL mice and suggest that QTL for complex epilepsies should be defined in terms of the environment in which they are expressed.

    Funded by: NICHD NIH HHS: HD39722; NINDS NIH HHS: NS23355

    Genes, brain, and behavior 2006;5;7;518-27

  • From the Cover: Indispensability of the glutamate transporters GLAST and GLT1 to brain development.

    Matsugami TR, Tanemura K, Mieda M, Nakatomi R, Yamada K, Kondo T, Ogawa M, Obata K, Watanabe M, Hashikawa T and Tanaka K

    Laboratory of Molecular Neuroscience, School of Biomedical Science and Medical Research Institute, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo 113-8510, Japan.

    Previous in vitro studies have shown that the neurotransmitter glutamate is important in brain development. Paradoxically, loss-of-function mouse models of glutamatergic signaling that are generated by genetic deletion of glutamate receptors or glutamate release show normal brain assembly. We examined the direct consequences on brain development of extracellular glutamate buildup due to the depletion of the glutamate transporters GLAST and GLT1. GLAST/GLT1 double knockout mice show multiple brain defects, including cortical, hippocampal, and olfactory bulb disorganization with perinatal mortality. Here, we report abnormal formation of the neocortex in GLAST/GLT1 mutants. Several essential aspects of neuronal development, such as stem cell proliferation, radial migration, neuronal differentiation, and survival of SP neurons, were impaired. These results provide direct in vivo evidence that GLAST and GLT1 are necessary for brain development through regulation of extracellular glutamate concentration and show that an important mechanism is likely to be maintenance of glutamate-mediated synaptic transmission.

    Proceedings of the National Academy of Sciences of the United States of America 2006;103;32;12161-6

  • Involvement of the AMPA receptor GluR-C subunit in alcohol-seeking behavior and relapse.

    Sanchis-Segura C, Borchardt T, Vengeliene V, Zghoul T, Bachteler D, Gass P, Sprengel R and Spanagel R

    Department of Psychopharmacology, Central Institute of Mental Health, University of Heidelberg, 68072 Mannheim, Germany. segura@zi-mannheim.de

    Craving and relapse are core symptoms of drug addiction and alcoholism. It is suggested that, after chronic drug consumption, long-lasting neuroplastic changes within the glutamatergic system are important determinants of addictive behavior. Here, we show that the AMPA type glutamate receptor plays a crucial role in alcohol craving and relapse. We observed, in two animal models of alcohol craving and relapse, that the AMPA antagonist GYKI 52466 [1-(4-aminophenyl)-4-methyl-7, 8-methylenedioxy-5H-2, 3-benzodiazepine] dose-dependently reduced cue-induced reinstatement of alcohol-seeking behavior and the alcohol deprivation effect. The involvement of the AMPA receptor in these phenomena was further studied using mice deficient for the GluR-C AMPA subunit [GluR-C knock-out (KO)]. GluR-C KOs displayed a blunted, cue-induced reinstatement response and alcohol deprivation effect, when compared with wild-type controls; however, no differences between genotypes could be observed regarding ethanol self-administration under operant or home cage drinking conditions. These results imply a role for GluR-C in alcohol relapse, although this phenotype could also be attributable to a reduction in the total number of AMPA receptors in specific brain areas. In conclusion, AMPA receptors seem to be involved in the neuroplastic changes underlying alcohol seeking behavior and relapse. Thus, AMPA receptors represent a novel therapeutic target in preventing relapse.

    The Journal of neuroscience : the official journal of the Society for Neuroscience 2006;26;4;1231-8

  • Neurotransmitter release regulated by a MALS-liprin-alpha presynaptic complex.

    Olsen O, Moore KA, Fukata M, Kazuta T, Trinidad JC, Kauer FW, Streuli M, Misawa H, Burlingame AL, Nicoll RA and Bredt DS

    Department of Physiology, University of California, San Francisco, San Francisco, CA 94143, USA.

    Synapses are highly specialized intercellular junctions organized by adhesive and scaffolding molecules that align presynaptic vesicular release with postsynaptic neurotransmitter receptors. The MALS/Veli-CASK-Mint-1 complex of PDZ proteins occurs on both sides of the synapse and has the potential to link transsynaptic adhesion molecules to the cytoskeleton. In this study, we purified the MALS protein complex from brain and found liprin-alpha as a major component. Liprin proteins organize the presynaptic active zone and regulate neurotransmitter release. Fittingly, mutant mice lacking all three MALS isoforms died perinatally with difficulty breathing and impaired excitatory synaptic transmission. Excitatory postsynaptic currents were dramatically reduced in autaptic cultures from MALS triple knockout mice due to a presynaptic deficit in vesicle cycling. These findings are consistent with a model whereby the MALS-CASK-liprin-alpha complex recruits components of the synaptic release machinery to adhesive proteins of the active zone.

    The Journal of cell biology 2005;170;7;1127-34

  • Differential regulation of AMPA receptor subunit trafficking by palmitoylation of two distinct sites.

    Hayashi T, Rumbaugh G and Huganir RL

    Howard Hughes Medical Institute, Department of Neuroscience, Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, Maryland 21205, USA.

    Modification of AMPA receptor function is a major mechanism for the regulation of synaptic transmission and underlies several forms of synaptic plasticity. Post-translational palmitoylation is a reversible modification that regulates localization of many proteins. Here, we report that palmitoylation of the AMPA receptor regulates receptor trafficking. All AMPA receptor subunits are palmitoylated on two cysteine residues in their transmembrane domain (TMD) 2 and in their C-terminal region. Palmitoylation on TMD 2 is upregulated by the palmitoyl acyl transferase GODZ and leads to an accumulation of the receptor in the Golgi and a reduction of receptor surface expression. C-terminal palmitoylation decreases interaction of the AMPA receptor with the 4.1N protein and regulates AMPA- and NMDA-induced AMPA receptor internalization. Moreover, depalmitoylation of the receptor is regulated by activation of glutamate receptors. These data suggest that regulated palmitoylation of AMPA receptor subunits modulates receptor trafficking and may be important for synaptic plasticity.

    Neuron 2005;47;5;709-23

  • Molecular constituents of neuronal AMPA receptors.

    Fukata Y, Tzingounis AV, Trinidad JC, Fukata M, Burlingame AL, Nicoll RA and Bredt DS

    Department of Physiology, University of California, San Francisco, San Francisco, CA 94143, USA.

    Dynamic regulation of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) underlies aspects of synaptic plasticity. Although numerous AMPAR-interacting proteins have been identified, their quantitative and relative contributions to native AMPAR complexes remain unclear. Here, we quantitated protein interactions with neuronal AMPARs by immunoprecipitation from brain extracts. We found that stargazin-like transmembrane AMPAR regulatory proteins (TARPs) copurified with neuronal AMPARs, but we found negligible binding to GRIP, PICK1, NSF, or SAP-97. To facilitate purification of neuronal AMPAR complexes, we generated a transgenic mouse expressing an epitope-tagged GluR2 subunit of AMPARs. Taking advantage of this powerful new tool, we isolated two populations of GluR2 containing AMPARs: an immature complex with the endoplasmic reticulum chaperone immunoglobulin-binding protein and a mature complex containing GluR1, TARPs, and PSD-95. These studies establish TARPs as the auxiliary components of neuronal AMPARs.

    Funded by: NIMH NIH HHS: R01 MH070957, R56 MH070957

    The Journal of cell biology 2005;169;3;399-404

  • Development of a new genetic model for absence epilepsy: spike-wave seizures in C3H/He and backcross mice.

    Frankel WN, Beyer B, Maxwell CR, Pretel S, Letts VA and Siegel SJ

    The Jackson Laboratory, Bar Harbor, Maine 04609, USA. wnf@jax.org

    To characterize the genetic basis of spike-wave discharges (SWDs) detected by electroencephalography (EEG) in C3H/He mice, substrains of C3H mice were evaluated by EEG and sensitivity to ethosuximide. Crosses with the SWD-negative strain C57BL/6J were performed to map the underlying gene(s). C3H/He substrains exhibited a modest incidence (average of 19 SWDs per hour) of 7-8 Hz SWDs when at rest, compared with the C3HeB/Fe subline (four SWDs per hour). In the mapping backcross, however, many mice showed a very high incidence (50-220 SWDs per hour) throughout the recording period. SWDs were first detected at 3.5 weeks of age, were associated with behavioral arrest, were suppressed by ethosuximide, and were strongest in the cerebral cortex and thalamus. The major C3H determinant of SWDs, spkw1 (spike-wave 1), mapped to chromosome (Chr 9), and together with a C57BL/6J determinant on Chr 8, spkw2, accounted for more than one-half of the phenotypic variation in the backcross mice. The modest SWD incidence in C3H/He mice and the high incidence in backcrosses implies that SWD could be a confounding variable for other behaviors. Because C3H/He mice have no other brain abnormalities, they are an attractive alternative for studying idiopathic absence epilepsy.

    Funded by: NIMH NIH HHS: P50 MH 6404501; NINDS NIH HHS: NS31348

    The Journal of neuroscience : the official journal of the Society for Neuroscience 2005;25;13;3452-8

  • Calcium-permeable AMPA receptor plasticity is mediated by subunit-specific interactions with PICK1 and NSF.

    Gardner SM, Takamiya K, Xia J, Suh JG, Johnson R, Yu S and Huganir RL

    Department of Neuroscience, Johns Hopkins University, School of Medicine, Howard Hughes Medical Institute, 725 North Wolfe Street, Baltimore, Maryland 21205, USA.

    A recently described form of synaptic plasticity results in dynamic changes in the calcium permeability of synaptic AMPA receptors. Since the AMPA receptor GluR2 subunit confers calcium permeability, this plasticity is thought to occur through the dynamic exchange of synaptic GluR2-lacking and GluR2-containing receptors. To investigate the molecular mechanisms underlying this calcium-permeable AMPA receptor plasticity (CARP), we examined whether AMPA receptor exchange was mediated by subunit-specific protein-protein interactions. We found that two GluR2-interacting proteins, the PDZ domain-containing Protein interacting with C kinase (PICK1) and N-ethylmaleimide sensitive fusion protein (NSF), are specifically required for CARP. Furthermore, PICK1, but not NSF, regulates the formation of extrasynaptic plasma membrane pools of GluR2-containing receptors that may be laterally mobilized into synapses during CARP. These results demonstrate that PICK1 and NSF dynamically regulate the synaptic delivery of GluR2-containing receptors during CARP and thus regulate the calcium permeability of AMPA receptors at excitatory synapses.

    Funded by: NINDS NIH HHS: NS36715, NS43061

    Neuron 2005;45;6;903-15

  • Differential expression of alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionate glutamate receptors in the rat striatum during postnatal development.

    Chan WS, Yeung CW, Chung EK, Lau WK, Chan YS and Yung KK

    Department of Biology, Hong Kong Baptist University, Kowloon Tong, PR China.

    Alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionate (AMPA)-type glutamate receptors (GluR1-4) are one of the most important ionotropic glutamate receptors in the striatum, a key region of the basal ganglia. The present study investigated the trend of developmental expression of AMPA receptor subunits in the striatum of rats in different developmental stages, i.e., at postnatal day 7 (PND7), PND21 and adult. Perfuse-fixed striatal sections were used. The expression of AMPA subunits was studied by immunofluorescence and reverse transcriptase-polymerase chain reaction (RT-PCR). RT-PCR revealed that the levels of expression of the GluR1 and GluR3 mRNAs were the same among the age groups. The level of GluR2 mRNA was highest in PND21 rats and lowest in adult. The highest level of GluR4 mRNA was detected in rats at PND7. Similar trends of GluR1, GluR2 and GluR2/3 immunoreactivity expression were observed using commercially available specific antibodies. In addition, a large proportion of parvalbumin-immunoreactive GABAergic interneurons in the striatum were found to display GluR1 immunoreactivity in PND21 and adult rats. In contrast, most of the choline acetyltransferase-immunoreactive cholinergic interneurons were found to display GluR2 immunoreactivity but less GluR1 and no GluR2/3 immunoreactivity in PND21 and adult rats. The present study suggests that there is a distinct pattern of expression of AMPA-type receptor mRNAs and proteins in the rat striatum at different stages of development.

    Neuro-Signals 2003;12;6;302-9

  • AMPA receptors regulate dynamic equilibrium of presynaptic terminals in mature hippocampal networks.

    De Paola V, Arber S and Caroni P

    Friedrich Miescher Institut, Maulbeerstrasse 66, CH-4058, Basel, Switzerland.

    The formation and disassembly of synapses in mature neuropil could provide a substrate to encode experience in the brain. Although there is evidence for postsynaptic spine dynamics in mature systems, contributions to circuit rearrangements by presynaptic terminals have remained unclear. We used hippocampal slice cultures from mice expressing spectral variants of green fluorescent protein (GFP) that are targeted to the membrane and/or synaptic vesicles in neuronal subsets to image identified presynaptic terminals. In mature tissues with no net change in synapse numbers, subpopulations of presynaptic terminals appeared and disappeared within 1-3 days. The three terminal types established by mossy fibers had distinct properties. High-frequency stimulation increased the fraction of dynamic terminals for 1-2 days, a process mediated by activation of AMPA receptors, protein kinase A (PKA) and protein synthesis. Thus, synaptic activity can make stable presynaptic terminals become dynamic, providing a candidate mechanism to convert experience into changes in network connectivity.

    Nature neuroscience 2003;6;5;491-500

  • A phylogenetic analysis reveals an unusual sequence conservation within introns involved in RNA editing.

    Aruscavage PJ and Bass BL

    Department of Biochemistry/Howard Hughes Medical Institute, University of Utah, Salt Lake City 84132, USA.

    Adenosine deaminases that act on RNA (ADARs) are RNA editing enzymes that convert adenosines to inosines within cellular and viral RNAs. Certain glutamate receptor (gluR) pre-mRNAs are substrates for the enzymes in vivo. For example, at the R/G editing site of gluR-B, -C, and -D RNAs, ADARs change an arginine codon (AGA) to a glycine codon (IGA) so that two protein isoforms can be synthesized from a single encoded mRNA; the highly related gluR-A sequence is not edited at this site. To gain insight into what features of an RNA substrate are important for accurate and efficient editing by an ADAR, we performed a phylogenetic analysis of sequences required for editing at the R/G site. We observed highly conserved sequences that were shared by gluR-B, -C, and -D, but absent from gluR-A. Surprisingly, in contrast to results obtained in phylogenetic analyses of tRNA and rRNA, it was the bases in paired, helical regions whose identity was conserved, whereas bases in nonhelical regions varied, but maintained their nonhelical state. We speculate this pattern in part reflects constraints imposed by ADAR's unique specificity and gained support for our hypotheses with mutagenesis studies. Unexpectedly, we observed that some of the gluR introns were conserved beyond the sequences required for editing. The approximately 600-nt intron 13 of gluR-C was particularly remarkable, showing >94% nucleotide identity between human and chicken, organisms estimated to have diverged 310 million years ago.

    Funded by: NCI NIH HHS: 5P30CA42014; NIGMS NIH HHS: GM44073, R01 GM044073, R01 GM044073-11

    RNA (New York, N.Y.) 2000;6;2;257-69

  • ADAM-TS8, a novel metalloprotease of the ADAM-TS family located on mouse chromosome 9 and human chromosome 11.

    Georgiadis KE, Hirohata S, Seldin MF and Apte SS

    Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA.

    A disintegrin-like and metalloprotease domain with thrombospondin type I modules (ADAM-TS) describes a novel family of zinc metalloendopeptidases. Its members have a common domain organization, which includes, typically, a pre-pro-metalloprotease domain, a disintegrin-like domain, and one or more thrombospondin-like (TS) modules. We describe here the complete primary structure of mouse ADAM-TS8, through cloning of Adamts8 cDNA. This novel member of the family contains two TS modules and is highly similar in sequence and domain organization to three other recently described gene products, ADAM-TS5, ADAM-TS6, and ADAM-TS7. Adamts8 is expressed at low levels throughout development and in adult mouse lung and heart. Through analysis of an interspecific backcross panel, we place the Adamts8 locus on mouse chromosome 9 at a consensus position of 11 cM and its human ortholog, recently reported as the METH2 gene, on human chromosome 11q25.

    Funded by: NHGRI NIH HHS: HGO0734

    Genomics 1999;62;2;312-5

  • Detection and mapping of quantitative trait loci for haloperidol-induced catalepsy in a C57BL/6J x DBA/2J F2 intercross.

    Patel NV and Hitzemann RJ

    Department of Psychiatry, SUNY 11794-8101, USA.

    A genomewide scan was conducted to detect quantitative trait loci (QTLs) for haloperidol-induced catalepsy in a C57BL/6J (B6) x DBA/2J (D2) F2 intercross (N = 678). Significant QTLs (LOD, > 4.3) were detected on chromosomes 1 and 9. The relative position of the QTL on chromosome 1 is similar to open-field activity QTLs previously identified by Flint et al. (1995) and Gershenfeld et al. (1997). Given the broad confidence intervals for these QTLs, such associations must be viewed cautiously. However, these data are consistent with the report of Kline et al. (1998), who found a significant genetic associations between catalepsy and open-field activity. The QTL interval on chromosome 9 stretched from approximately 25 to 55 cM; this region contains numerous candidate genes, including Drd2, Ncam, Acat1, and Htr1b. The data also suggest the presence of a second QTL on chromosome 9 (LOD, > 3.5) in the proximal region of the chromosome. Potential candidate genes in this region include Penk2 and Gria4. Overall, these data support our previous observation (Kanes et al., 1996) that for the B6 x D2 genotypes, one or more polymorphisms on chromosome 9 are associated with the variance in haloperidol response.

    Funded by: NIMH NIH HHS: MH 51372

    Behavior genetics 1999;29;5;303-10

  • Impairment of AMPA receptor function in cerebellar granule cells of ataxic mutant mouse stargazer.

    Hashimoto K, Fukaya M, Qiao X, Sakimura K, Watanabe M and Kano M

    Department of Physiology, Jichi Medical School, Minamikawachi-machi, Tochigi-ken 329-0498, Japan.

    The spontaneous recessive mutant mouse stargazer (stg) begins to show ataxia around postnatal day 14 and display a severe impairment in the acquisition of classical eyeblink conditioning in adulthood. These abnormalities have been attributed to the specific reduction in brain-derived neurotrophic factor (BDNF) and the subsequent defect in TrkB receptor signaling in cerebellar granule cells (GCs). In the stg mutant cerebellum, we found that EPSCs at mossy fiber (MF) to GC synapses are devoid of the fast component mediated by AMPA-type glutamate receptors despite the normal slow component mediated by NMDA receptors. The sensitivity of stg mutant GCs to exogenously applied AMPA was greatly reduced, whereas that to NMDA was unchanged. Glutamate release from MF terminals during synaptic transmission to GCs appeared normal. By contrast, AMPA receptor-mediated EPSCs were normal in CA1 pyramidal cells of the stg mutant hippocampus. Thus, postsynaptic AMPA receptor function was selectively impaired in stg mutant GCs, although the transcription of four AMPA receptor subunit genes in the stg GC was comparable to the wild-type GC. We also examined the cerebellum of BDNF knockout mice and found that their MF-GC synapses had a normal AMPA receptor-mediated EPSC component. Thus, the impaired AMPA receptor function in the stg mutant GC is not likely to result from the reduced BDNF-TrkB signaling. These results suggest that the defect in MF to GC synaptic transmission is a major factor that causes the cerebellar dysfunction in the stg mutant mouse.

    The Journal of neuroscience : the official journal of the Society for Neuroscience 1999;19;14;6027-36

  • Contribution of metabotropic glutamate receptor mGluR4 to L-2-[3H]amino-4-phosphonobutyrate binding in mouse brain.

    Thomsen C and Hampson DR

    Department of Molecular Pharmacology, Novo Nordisk A/S, Måløv, Denmark.

    The binding of L-2-[3H]amino-4-phosphonobutyrate ([3H]L-AP4) was examined in brain sections of wild-type mice and mice lacking the mGluR4 subtype of metabotropic glutamate receptors (mGluRs). Very high relative densities of [3H]L-AP4 binding were observed in the molecular layer of the cerebellar cortex, the nucleus basalis, the outer layer of the superior colliculus, and the substantia nigra. In mGluR4 knock-out mice, very low levels of binding were observed in these regions. The moderate levels of binding observed with wild-type mice in the molecular layer of the hippocampal dentate gyrus and in the thalamus were absent in mGluR4 knock-out mice. In contrast, the moderate levels observed in most of the cerebral cortex, caudate putamen, and globus pallidus were not different in mGluR4 knock-out mice compared with wild-type. In these regions, mGluR8 is likely to be labeled by [3H]L-AP4 because mGluR8 is expressed in such brain regions and, like mGluR4, has high affinity for L-AP4. We conclude that mGluR4 contributes substantially to the high-affinity binding site for [3H]L-AP4 in several regions of mouse brain, including cerebellar cortex, nucleus basalis, thalamus, superior colliculus, substantia nigra, and hippocampal dentate gyrus.

    Journal of neurochemistry 1999;72;2;835-40

  • Glutamate receptors: brain function and signal transduction.

    Nakanishi S, Nakajima Y, Masu M, Ueda Y, Nakahara K, Watanabe D, Yamaguchi S, Kawabata S and Okada M

    Department of Biological Sciences, Kyoto University Faculty of Medicine, Yoshida, Sakyo-ku, Kyoto 606, Japan. snakanis@phy.med.kyoto-u.ac.jp

    Glutamate receptors are important in neural plasticity, neural development and neurodegeneration. N-methyl-d-aspartate (NMDA) receptors and alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA)/kainate receptors act as glutamate-gated cation channels, whereas metabotropic receptors (mGluRs) modulate the production of second messengers via G proteins. Molecular studies from our and other laboratories indicated that NMDA receptors and mGluRs exist as multiple subunits (NMDAR1 and NMDAR2A-2D) and multiple subtypes (mGluR1-mGluR8). In light of the molecular diversity of glutamate receptors, we explored the function and intracellular signaling mechanisms of different members of glutamate receptors. In the visual system, retinal bipolar cells receive glutamate transmission from photoreceptors and contribute to segregating visual signals into ON and OFF pathways. The molecularly cloned mGluR6 is restrictedly expressed at the postsynaptic site of ON-bipolar cells in both rod and cone systems. Gene targeting of mGluR6 results in a loss of ON responses without changing OFF responses and severely impairs detecting visual contrasts. Since AMPA receptors mediate OFF responses in OFF-bipolar cells, two distinct types of glutamate receptors effectively operate for ON and OFF responses. mGluR1 and mGluR5 are both coupled to inositol triphosphate (IP3)/calcium signal transduction with an identical agonist selectivity. Single-cell intracellular calcium ([Ca2+]i) recordings indicated that glutamate evokes a non-oscillatory and oscillatory [Ca2+]i response in mGluR1-expressing and mGluR5-expressing cells, respectively. This difference results from a single amino acid substitution, aspartate of mGluR1 or threonine of mGluR5, at the G protein-interacting carboxy-terminal domains. Protein kinase C phosphorylation of the threonine of mGluR5 is responsible for inducing [Ca2+]i oscillations in mGluR5-expressing cells and cultured glial cells. Thus, the two closely related mGluR subtypes mediate diverging intracellular signaling in glutamate transmission.

    Brain research. Brain research reviews 1998;26;2-3;230-5

  • Allosteric modulation of AMPA-type glutamate receptors increases activity of the promoter for the neural cell adhesion molecule, N-CAM.

    Holst BD, Vanderklish PW, Krushel LA, Zhou W, Langdon RB, McWhirter JR, Edelman GM and Crossin KL

    Department of Neurobiology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.

    To study regulation in vivo of the promoter for the neural cell adhesion molecule, N-CAM, we have used homologous recombination to insert the bacterial lacZ gene between the transcription and translation initiation sites of the N-CAM gene. This insertion disrupts the gene and places the expression of beta-galactosidase under the control of the N-CAM promoter. Animals homozygous for the disrupted allele did not express N-CAM mRNA or protein, but the pattern of beta-galactosidase expression in heterozygous and homozygous embryos was similar to that of N-CAM mRNA in wild-type animals. The homozygotes exhibited many of the morphological abnormalities observed in previously reported N-CAM knockout mice, with the exception that hippocampal long-term potentiation in the Schaffer collaterals was identical in homozygous, heterozygous, and wild-type animals. Heterozygous mice were used to examine the regulation of the N-CAM promoter in response to enhanced synaptic transmission. Treatment of the mice with an ampakine, an allosteric modulator of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors that enhances normal glutamate-mediated synaptic transmission, increased the expression of beta-galactosidase in vivo as well as in tissue slices in vitro. Similar treatments also increased the expression of N-CAM mRNA in the heterozygotes. The effects of ampakine in slices were strongly reduced in the presence of 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX), an AMPA receptor antagonist. Taken together, these results indicate that facilitation of AMPA receptor-mediated transmission leads to activation of the N-CAM promoter and provide support for the hypothesis that N-CAM synthesis is regulated in part by synaptic activity.

    Funded by: NICHD NIH HHS: HD09635, R01 HD009635

    Proceedings of the National Academy of Sciences of the United States of America 1998;95;5;2597-602

  • AMPA receptor subunits expressed by single astrocytes in the juvenile mouse hippocampus.

    Seifert G, Rehn L, Weber M and Steinhäuser C

    Institute of Physiology, Department of Neurophysiology, Friedrich-Schiller University Jena, Germany.

    The subunit composition of native AMPA receptor (AMPA-R) channels was recently described in several neuronal cell types but less information is available on glial cells. Evidence from recombinant receptor studies suggests that the expression of distinct subunits determines the specific functional properties of the receptor channel. In the present study, we combined the patch clamp technique with the reverse transcription-polymerase chain reaction (RT-PCR) to correlate the expression of gene transcripts with functional properties of AMPA-R in single identified glial cells of the hippocampus. The cells were freshly isolated from the stratum radiatum of the CA1 subregion. We focused on cells expressing AMPA-R with an intermediate Ca2+ permeability which were identified as immature astrocytes due to their morphological, immunocytochemical and electrophysiological characteristics. After recording, the cells were harvested and RT-PCR was performed with the same individual cell to investigate the composition of their AMPA-R transcripts. Our results suggest the expression of a heteromeric subunit architecture. In all cells, the GluR2 subunit was present, which is known to confer a low Ca2+ permeability to the receptor complex. Most frequently, we met co-expression of GluR2 and GluR4. This study demonstrates that astrocytes in the hippocampus express a distinct AMPA-R subunit composition which differs from neurons. The glial receptors might be involved in the modulation of gene expression as well as the regulation of proliferation and differentiation.

    Brain research. Molecular brain research 1997;47;1-2;286-94

  • Partial structure, chromosome localization, and expression of the mouse Girk4 gene.

    Wickman K, Seldin MF, Gendler SJ and Clapham DE

    Children's Hospital Medical Center, Harvard Medical School, Enders Building, Room 1309, 320 Longwood Avenue, Boston, Massachusetts 02115, USA.

    The G protein-gated potassium channel IKACh constitutes part of a signaling pathway that mediates the negative chronotropic and inotropic effects of acetylcholine on cardiac physiology. Similar or identical ion channels regulate the excitability of many neurons in response to neurotransmitters. IKACh is composed of two homologous subunits, GIRK1 and GIRK4. Here we describe a partial genomic structure of the mouse Girk4 gene. Two exons containing the complete protein-coding sequence were identified. Girk4 was mapped to mouse chromosome 9 (13 cM), consistent with the mapping of human GIRK4 to chromosome 11q23-ter. GIRK4 mRNA was found mainly in mouse heart, with trace levels detected in brain, kidney, lung, and spleen. No detectable levels were observed in skeletal muscle, liver, and testis. The onset of GIRK4 mRNA expression in the developing mouse occurs between Embryonic Days 7 and 11, consistent with the appearance and function of the mouse heart.

    Funded by: NHGRI NIH HHS: HG00734

    Genomics 1997;40;3;395-401

  • Glutamate receptors in cortical plasticity: molecular and cellular biology.

    Kaczmarek L, Kossut M and Skangiel-Kramska J

    Department of Neurophysiology, Nencki Institute, Warsaw, Poland.

    Glutamate receptors (GluRs) provide the major excitatory input to cortical neurons. Four main subtypes of GluRs are distinguished, namely, N-methyl-D-aspartate, alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid, kainate, and metabotropic receptors. All of them have been implicated in neuronal plasticity, and this paper reviews data that may be pertinent to the role played by GluRs in neocortical plasticity both in adult animals as well as during postnatal development. Emphasis is given to receptor distribution analyzed by various means, such as physiological responses, ligand binding as revealed by receptor autoradiography, and expression of receptor subunits at both mRNA and protein (immunoreactivity) levels. Possible mechanisms of involvement of GluRs in plastic changes on cortical neuron response are reviewed, and data on up- and downregulation of GluRs in neocortical plasticity are summarized. Functional studies involving either activation or blocking, and effects of such manipulation on cortical plasticity are discussed.

    Physiological reviews 1997;77;1;217-55

  • Expression of glutamate receptor subunit genes during development of the mouse retina.

    Zhang C, Hammassaki-Britto DE, Britto LR and Duvoisin RM

    Margaret M. Dyson Vision Research Institute, Department of Ophthalmology, Cornell University Medical College, New York, NY 10021, USA.

    The distribution of expression during retinal differentiation of nine AMPA and kainate glutamate receptor subunit genes was studied by in situ hybridization. Transcripts encoding all subunits were detected in the inner nuclear and ganglion cell layers of the developing mouse retina, but their time courses of expression differed. The earliest expression was detected at embryonic day 14 (E14) for GluR1, GluR4 and KA-2; all the other subunits were first detected at E16. Most subunits were expressed at higher levels during development than in the adult. This suggests they play a role in the processes of neuronal differentiation and synaptogenesis that occur during the early postnatal days in the rodent retina.

    Funded by: NEI NIH HHS: EY09534

    Neuroreport 1996;8;1;335-40

  • Assignment of the mouse ataxia-telangiectasia gene (Atm) to mouse chromosome 9.

    Xia Y, Welch CL, Warden CH, Lange E, Fukao T, Lusis AJ and Gatti RA

    Department of Medicine, 47-123 Center for the Health Sciences, UCLA, Los Angeles, California 90095-1679, USA.

    Funded by: NHLBI NIH HHS: HL28481, HL42488

    Mammalian genome : official journal of the International Mammalian Genome Society 1996;7;7;554-5

  • Genetic regulation of cholesterol homeostasis: chromosomal organization of candidate genes.

    Welch CL, Xia YR, Shechter I, Farese R, Mehrabian M, Mehdizadeh S, Warden CH and Lusis AJ

    Department of Pathology, University of California, Los Angeles 90095, USA.

    As part of an effort to dissect the genetic factors involved in cholesterol homeostasis in the mouse model, we report the mapping of 12 new candidate genes using linkage analysis. The genes include: cytoplasmic HMG-CoA synthase (Hmgcs 1, Chr 13), mitochondrial synthase (Hmgcs 2, Chr 3), a synthase-related sequence (Hmgcs 1-rs, Chr 12), mevalonate kinase (Mvk, Chr 5), farnesyl diphosphate synthase (Fdps, Chr 3), squalene synthase (Fdft 1, Chr 14), acyl-CoA:cholesterol acyltransferase (Acact, Chr 1), sterol regulatory element binding protein-1 (Srebf1, Chr 8) and -2 (Srebf2, Chr 15), apolipoprotein A-I regulatory protein (Tcfcoup2, Chr 7), low density receptor-related protein-related sequence (Lrp-rs, Chr 10), and Lrp-associated protein (Lrpap 1, Chr 5). In addition, the map positions for several lipoprotein receptor genes were refined. These genes include: low density lipoprotein receptor (Ldlr, Chr 9), very low density lipoprotein receptor (Vldlr, Chr 19), and glycoprotein 330 (Gp330, Chr 2). Some of these candidate genes are located within previously defined chromosomal regions (quantitative trait loci, QTLs) contributing to plasma lipoprotein levels, and Acact maps near a mouse mutation, ald, resulting in depletion of cholesteryl esters in the adrenals. The combined use of QTL and candidate gene mapping provides a powerful means of dissecting complex traits such as cholesterol homeostasis.

    Funded by: NHLBI NIH HHS: HL30568, HL42488, HL48540

    Journal of lipid research 1996;37;7;1406-21

  • Chromosomal localization of glutamate receptor genes: relationship to familial amyotrophic lateral sclerosis and other neurological disorders of mice and humans.

    Gregor P, Reeves RH, Jabs EW, Yang X, Dackowski W, Rochelle JM, Brown RH, Haines JL, O'Hara BF, Uhl GR et al.

    Molecular Neurobiology Section, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD 21224.

    Receptors for the major excitatory neurotransmitter glutamate may play key roles in neurodegeneration. The mouse Glur-5 gene maps to chromosome 16 between App and Sod-1. The homologous human GLUR5 gene maps to the corresponding region of human chromosome 21, which contains the locus for familial amyotrophic lateral sclerosis. This location, and other features, render GLUR5 a possible candidate gene for familial amyotrophic lateral sclerosis. In addition, dosage imbalance of GLUR5 may have a role in the trisomy 21 (Down syndrome). Further characterization of the murine glutamate receptor family includes mapping of Glur-1 to the same region as neurological mutants spasmodic, shaker-2, tipsy, and vibrator on chromosome 11; Glur-2 near spastic on chromosome 3; Glur-6 near waltzer and Jackson circler on chromosome 10; and Glur-7 near clasper on chromosome 4.

    Funded by: NHGRI NIH HHS: HG00101, HG00324, HG00465

    Proceedings of the National Academy of Sciences of the United States of America 1993;90;7;3053-7

  • Chromosomal localization of human glutamate receptor genes.

    McNamara JO, Eubanks JH, McPherson JD, Wasmuth JJ, Evans GA and Heinemann SF

    Department of Veterans Affairs Medical Center, Durham, NC.

    The chromosomal localization of human glutamate receptor genes (GluR1-4) has been established using PCR with DNA isolated from mapping panels of Chinese hamster-human hybrid cell lines and high-resolution fluorescent in situ suppression hybridization. This was accomplished with genomic clones containing putative human homologs of rat GluR 1-4 isolated by high-stringency screening of a cosmid library with the rat cDNAs encoding GluR1-4. The locations of GluR1-4, respectively, are 5q32-33, 4q32-33, Xq25-26, and 11q22-23. Evidence implicating glutamatergic synapses in a diversity of physiologic and pathologic processes together with concordance of the chromosomal locales and results of linkage analyses establishes GluR3 and GluR4 as candidate genes for a number of nervous system disorders including the oculocerebral-renal syndrome of Lowe and a form of manic-depressive illness.

    Funded by: NHGRI NIH HHS: HG00320; NINDS NIH HHS: NS17771, NS24448; ...

    The Journal of neuroscience : the official journal of the Society for Neuroscience 1992;12;7;2555-62

  • Cloning and functional expression of a cDNA encoding the mouse beta 2 subunit of the kainate-selective glutamate receptor channel.

    Morita T, Sakimura K, Kushiya E, Yamazaki M, Meguro H, Araki K, Abe T, Mori KJ and Mishina M

    Department of Neuropharmacology, Faculty of Science, Niigata University, Japan.

    The primary structure of the mouse glutamate receptor beta 2 subunit has been deduced by cloning and sequencing cDNA. The beta 2 subunit has structural characteristics common to the subunits of glutamate-gated ion channels. Expression of the cloned cDNA in Xenopus oocytes yields functional glutamate receptor channels selective for kainate.

    Brain research. Molecular brain research 1992;14;1-2;143-6

  • Primary structure and expression of the gamma 2 subunit of the glutamate receptor channel selective for kainate.

    Sakimura K, Morita T, Kushiya E and Mishina M

    Department of Neuropharmacology, Brain Research Institute, Niigata University, Japan.

    The presence and primary structure of a novel subunit of the mouse glutamate receptor channel, designated as gamma 2, have been revealed by cloning and sequencing the cDNA. The gamma 2 subunit has structural characteristics common to the neurotransmitter-gated ion channel family and shares a high amino acid sequence identity with the rat KA-1 subunit, thus constituting the gamma subfamily of the glutamate receptor channel. Expression of the gamma 2 subunit together with the beta 2 subunit in Xenopus oocytes yields functional glutamate receptor channels selective for kainate.

    Neuron 1992;8;2;267-74

  • RNA editing in brain controls a determinant of ion flow in glutamate-gated channels.

    Sommer B, Köhler M, Sprengel R and Seeburg PH

    Laboratory for Molecular Neuroendocrinology, University of Heidelberg, Federal Republic of Germany.

    L-glutamate, the principal excitatory transmitter in the brain, gates ion channels mediating fast neurotransmission. Subunit components of two related classes of glutamate receptor channels have been characterized by cDNA cloning and shown to carry either an arginine or a glutamine residue in a defined position of their putative channel-forming segment. The arginine residue in this segment profoundly alters, and dominates, the properties of ion flow, as demonstrated for one channel class. We now show that the genomic DNA sequences encoding the particular channel segment of all subunits harbor a glutamine codon (CAG), even though an arginine codon (CGG) is found in mRNAs of three subunits. Multiple genes and alternative exons were excluded as sources for the arginine codon; hence, we propose that transcripts for three subunits are altered by RNA editing. This process apparently edits subunit transcripts of the two glutamate receptor classes with different efficiency and selectivity.

    Cell 1991;67;1;11-9

Gene lists (7)

Gene List Source Species Name Description Gene count
L00000001 G2C Mus musculus Mouse PSD Mouse PSD adapted from Collins et al (2006) 1080
L00000006 G2C Mus musculus Mouse ARC Mouse AMPA receptor complex adapted from Collins et al (2006) 9
L00000008 G2C Mus musculus Mouse PSP Mouse PSP adapted from Collins et al (2006) 1121
L00000050 G2C Mus musculus TAP-PSD-95-CORE TAP-PSD-95 pull-down core list 120
L00000062 G2C Mus musculus BAYES-COLLINS-MOUSE-PSD-CONSENSUS Mouse cortex PSD consensus 984
L00000070 G2C Mus musculus BAYES-COLLINS-HUMAN-PSD-FULL Human cortex biopsy PSD full list (ortho) 1461
L00000072 G2C Mus musculus BAYES-COLLINS-MOUSE-PSD-FULL Mouse cortex PSD full list 1556
© G2C 2014. The Genes to Cognition Programme received funding from The Wellcome Trust and the EU FP7 Framework Programmes:
EUROSPIN (FP7-HEALTH-241498), SynSys (FP7-HEALTH-242167) and GENCODYS (FP7-HEALTH-241995).

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