G2Cdb::Gene report

Gene id
G00000089
Gene symbol
Kcnj4 (MGI)
Species
Mus musculus
Description
potassium inwardly-rectifying channel, subfamily J, member 4
Orthologue
G00001338 (Homo sapiens)

Databases (7)

Gene
ENSMUSG00000044216 (Ensembl mouse gene)
16520 (Entrez Gene)
425 (G2Cdb plasticity & disease)
Gene Expression
NM_008427 (Allen Brain Atlas)
Literature
600504 (OMIM)
Marker Symbol
MGI:104743 (MGI)
Protein Sequence
P52189 (UniProt)

Synonyms (4)

  • IRK3
  • Kcnf2
  • Kir 2.3
  • MB-IRK3

Literature (24)

Pubmed - other

  • 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

  • Functional characterization of inward rectifier potassium ion channel in murine fetal ventricular cardiomyocytes.

    Liu A, Tang M, Xi J, Gao L, Zheng Y, Luo H, Hu X, Zhao F, Reppel M, Hescheler J and Liang H

    Department of Physiology, Tongji Medical College, Huazhong University of Science and Technology, Tongji Medical College, Huazhong University of Science and Technology, China.

    Aims: Previous studies have shown the dramatic changes in electrical properties of murine fetal cardiomyocytes, while details on inward rectifier potassium current (IK1) are still seldom discussed. Thus we aimed to characterize the functional expression and functional role of IK1 in murine fetal ventricular cardiomyocytes.

    Methods: Whole cell patch clamp was applied to investigate the electrophysiological properties of IK1. Quantitative real-time PCR, western blotting and double-label immunofluorescence were further utilized to find out the molecular basis of IK1.

    Results: Compared to early developmental stage (EDS), IK1 at late developmental stage (LDS) displayed higher current density, stronger rectifier property and faster activation kinetics. It was paralleled with the downregulation of Kir2.3 and the upregulation of Kir2.1/Kir2.2. IK1 contributed to maintain the maximum diastolic potential (MDP), late repolarization phase (LRP) as well as the action potential duration (APD). However, the contribution to MDP and velocity of LRP did not change significantly with maturation.

    Conclusions: During fetal development, the switch of IK1 subtypes from Kir2.1/Kir2.3 to Kir2.1 resulted in the dramatic changes in IK1 electrophysiological properties.

    Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry, and pharmacology 2010;26;3;413-20

  • Mechanical deformation of ventricular myocytes modulates both TRPC6 and Kir2.3 channels.

    Dyachenko V, Husse B, Rueckschloss U and Isenberg G

    Department of Physiology, Martin-Luther-University Halle, 06097 Halle, Germany.

    Cardiomyocytes respond to mechanical stretch with an increase [Ca2+]i. Here, we analyzed which ion channels could mediate this effect. Murine ventricular myocytes were attached to a glass coverslip and a cell-attached glass stylus sheared the upper cell part versus the attached cell bottom. At negative clamp potentials, stretch induced inward currents that increased with the extent of stretch and reversed within 2 min after relaxation from stretch. Stretch activated a nearly voltage-independent GsMTx-4-sensitive non-selective cation conductance Gns, antibodies against TRPC6 prevented Gns activation. In addition, stretch deactivated a Cs+-sensitive inwardly rectifying potassium conductance GK1, antibodies against Kir2.3 inhibited this effect. Immunolabeling localized TRPC6 and Kir2.3 in T-tubular membranes, and stretch-induced changes in membrane currents were absent in cells whose T-tubules had been removed. In absence of stretch, we could activate Gns and deactivate GK1 by 1-oleoyl-2-acetyl-sn-glycerol (OAG) and other amphipaths. We interpret that the function of TRPC6 and Kir2.3 channels is controlled by both tension and curvature of the surrounding lipid bilayer that are changed by incorporation of amphipaths. Stretch-activation of TRPC6 channels may increase Ca2+ influx directly and indirectly, by membrane depolarization (activation of voltage-gated Ca2+ channels) and by elevated [Na+]i (augmented Na+,Ca2+-exchange).

    Cell calcium 2009;45;1;38-54

  • Arachidonic acid activates Kir2.3 channels by enhancing channel-phosphatidyl-inositol 4,5-bisphosphate interactions.

    Wang C, Mirshahi UL, Liu B, Jia Z, Mirshahi T and Zhang H

    Weis Center for Research, Geisinger Clinic, 100 North Academy Avenue, Danville, PA 17822-2621, USA.

    Kir2.0 channels play a significant role in setting the resting membrane potential, modulating action potential wave form, and buffering extracellular potassium. One member of this family, Kir2.3, is highly expressed in the heart and brain and is modulated by a variety of factors, including arachidonic acid (AA). Using two-electrode voltage clamp and inside-out patch clamp recordings from Xenopus laevis oocytes expressing Kir2.3 channels, we found that AA selectively activated Kir2.3 channels with an EC(50) of 0.59 muM and that this activation required phosphatidyl inositol 4,5-bisphosphate (PIP(2)). We found that AA activated Kir2.3 by enhancing channel-PIP(2) interactions as demonstrated by a shift in PIP(2) activation curve. EC(50) for channel activation by PIP(2) were 36 and 12 muM in the absence and presence of AA, respectively. A single point mutation on the channel C terminus that enhanced basal channel-PIP(2) interactions reduced the sensitivity of the channel to AA. Effects of AA are mediated through cytoplasmic sites on the channel by increasing the open probability, mainly due to more frequent bursts of opening in the presence of PIP(2). Therefore, enhanced interaction with PIP(2) is the molecular mechanism for Kir2.3 channel activation by AA.

    Molecular pharmacology 2008;73;4;1185-94

  • Heterogeneity of IK1 in the mouse heart.

    Panama BK, McLerie M and Lopatin AN

    Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA.

    Previous studies have shown that cardiac inward rectifier potassium current (I(K1)) channels are heteromers of distinct Kir2 subunits and suggested that species- and tissue-dependent expression of these subunits may underlie variability of I(K1). In this study, we investigated the contribution of the slowly activating Kir2.3 subunit and free intracellular polyamines (PAs) to variability of I(K1) in the mouse heart. The kinetics of activation was measured in Kir2 concatemeric tetramers with known subunit stoichiometry. Inclusion of only one Kir2.3 subunit to a Kir2.1 channel led to an approximate threefold slowing of activation kinetics, with greater slowing on subsequent additions of Kir2.3 subunits. Activation kinetics of I(K1) in both ventricles and both atria was found to correspond to fast-activating Kir2.1/Kir2.2 channels, suggesting no major contribution of Kir2.3 subunits. In contrast, I(K1) displayed significant variation in both the current density and inward rectification, suggesting involvement of intracellular PAs. The total levels of PAs were similar across the mouse heart. Measurements of the free intracellular PAs in isolated myocytes, using transgenically expressed Kir2.1 channels as PA sensors, revealed "microheterogeneity" of I(K1) rectification as well as lower levels of free PAs in atrial myocytes compared with ventricular cells. These findings provide a quantitative explanation for the regional heterogeneity of I(K1).

    Funded by: NHLBI NIH HHS: R01 HL069052, R012 HL 069052; NIGMS NIH HHS: T32 GM 008322, T32 GM008322

    American journal of physiology. Heart and circulatory physiology 2007;293;6;H3558-67

  • Cholinergic modulation of Kir2 channels selectively elevates dendritic excitability in striatopallidal neurons.

    Shen W, Tian X, Day M, Ulrich S, Tkatch T, Nathanson NM and Surmeier DJ

    Department of Physiology and Institute of Neuroscience, Feinberg School of Medicine, Northwestern University, 303 E. Chicago Ave., Chicago, Illinois 60611, USA.

    Dopamine-depleting lesions of the striatum that mimic Parkinson's disease induce a profound pruning of spines and glutamatergic synapses in striatopallidal medium spiny neurons, leaving striatonigral medium spiny neurons intact. The mechanisms that underlie this cell type-specific loss of connectivity are poorly understood. The Kir2 K(+) channel is an important determinant of dendritic excitability in these cells. Here we show that opening of these channels is potently reduced by signaling through M1 muscarinic receptors in striatopallidal neurons, but not in striatonigral neurons. This asymmetry could be attributed to differences in the subunit composition of Kir2 channels. Dopamine depletion alters the subunit composition further, rendering Kir2 channels in striatopallidal neurons even more susceptible to modulation. Reduced opening of Kir2 channels enhances dendritic excitability and synaptic integration. This cell type-specific enhancement of dendritic excitability is an essential trigger for synaptic pruning after dopamine depletion, as pruning was prevented by genetic deletion of M1 muscarinic receptors.

    Funded by: NINDS NIH HHS: NS 34696

    Nature neuroscience 2007;10;11;1458-66

  • Large-scale analysis of ion channel gene expression in the mouse heart during perinatal development.

    Harrell MD, Harbi S, Hoffman JF, Zavadil J and Coetzee WA

    Pediatric Cardiology, New York University School of Medicine, New York, New York 10016, USA.

    The immature and mature heart differ from each other in terms of excitability, action potential properties, contractility, and relaxation. This includes upregulation of repolarizing K(+) currents, an enhanced inward rectifier K(+) (Kir) current, and changes in Ca(2+), Na(+), and Cl(-) currents. At the molecular level, the developmental regulation of ion channels is scantily described. Using a large-scale real-time quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) assay, we performed a comprehensive analysis of ion channel transcript expression during perinatal development in the embryonic (embryonic day 17.5), neonatal (postnatal days 1-2), and adult Swiss-Webster mouse hearts. These data are compared with publicly available microarray data sets (Cardiogenomics project). Developmental mRNA expression for several transcripts was consistent with the published literature. For example, transcripts such as Kir2.1, Kir3.1, Nav1.5, Cav1.2, etc. were upregulated after birth, whereas others [e.g., Ca(2+)-activated K(+) (KCa)2.3 and minK] were downregulated. Cl(-) channel transcripts were expressed at higher levels in immature heart, particularly those that are activated by intracellular Ca(2+). Defining alterations in the ion channel transcriptome during perinatal development will lead to a much improved understanding of the electrophysiological alterations occurring in the heart after birth. Our study may have important repercussions in understanding the mechanisms and consequences of electrophysiological alterations in infants and may pave the way for better understanding of clinically relevant events such as congenital abnormalities, cardiomyopathies, heart failure, arrhythmias, cardiac drug therapy, and the sudden infant death syndrome.

    Funded by: NHLBI NIH HHS: 1 R01 HL-64838

    Physiological genomics 2007;28;3;273-83

  • BGEM: an in situ hybridization database of gene expression in the embryonic and adult mouse nervous system.

    Magdaleno S, Jensen P, Brumwell CL, Seal A, Lehman K, Asbury A, Cheung T, Cornelius T, Batten DM, Eden C, Norland SM, Rice DS, Dosooye N, Shakya S, Mehta P and Curran T

    Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, Tennessee, United States.

    Funded by: NINDS NIH HHS: 5R37NS036558, N01-NS-0-2331, R37 NS036558

    PLoS biology 2006;4;4;e86

  • Dendritic excitability of mouse frontal cortex pyramidal neurons is shaped by the interaction among HCN, Kir2, and Kleak channels.

    Day M, Carr DB, Ulrich S, Ilijic E, Tkatch T and Surmeier DJ

    Department of Physiology, Northwestern University Medical School, Chicago, Illinois 60611, USA.

    Dendritically placed, voltage-sensitive ion channels are key regulators of neuronal synaptic integration. In several cell types, hyperpolarization/cyclic nucleotide gated (HCN) cation channels figure prominently in dendritic mechanisms controlling the temporal summation of excitatory synaptic events. In prefrontal cortex, the sustained activity of pyramidal neurons in working memory tasks is thought to depend on the temporal summation of dendritic excitatory inputs. Yet we know little about how this is accomplished in these neurons and whether HCN channels play a role. To gain a better understanding of this process, layer V-VI pyramidal neurons in slices of mouse prelimbic and infralimbic cortex were studied. Somatic voltage-clamp experiments revealed the presence of rapidly activating and deactivating cationic currents attributable to HCN1/HCN2 channels. These channels were open at the resting membrane potential and had an apparent half-activation voltage near -90 mV. In the same voltage range, K+ currents attributable to Kir2.2/2.3 and K+-selective leak (Kleak) channels were prominent. Computer simulations grounded in the biophysical measurements suggested a dynamic interaction among Kir2, Kleak, and HCN channel currents in shaping membrane potential and the temporal integration of synaptic potentials. This inference was corroborated by experiment. Blockade of Kir2/Kleak channels caused neurons to depolarize, leading to the deactivation of HCN channels, the initiation of regular spiking (4-5 Hz), and enhanced temporal summation of EPSPs. These studies show that HCN channels are key regulators of synaptic integration in prefrontal pyramidal neurons but that their functional contribution is dependent on a partnership with Kir2 and Kleak channels.

    Funded by: NIMH NIH HHS: MH62070

    The Journal of neuroscience : the official journal of the Society for Neuroscience 2005;25;38;8776-87

  • Neuronal vulnerability in mouse models of Huntington's disease: membrane channel protein changes.

    Ariano MA, Wagle N and Grissell AE

    Department of Neuroscience, The Chicago Medical School at Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064-3095, USA. marjorie.ariano@rosalindfranklin.edu

    Huntington's disease (HD) is caused by a polyglutamine expansion that results in atrophy of the striatum and frontal cortex during disease progression. HD-susceptible striatal neurons are affected chronologically with initial degeneration of the striatopallidal neurons then the striatonigral projections, whereas large aspiny striatal interneurons (LAN) survive. Two classes of critical membrane proteins were evaluated in transgenic mouse models to determine their association with HD susceptibility, which leads to dysfunction and death in selected striatal neuron populations. We examined potassium (K+) channel protein subunits that form membrane ionophores conducting inwardly and outwardly rectifying K+ currents. K+ channel protein staining was diminished substantially in the HD striatal projection neurons but was not expressed in the HD-resistant LAN. Because loss of K+ channel subunits depolarizes neurons, other voltage-gated ionophores will be affected. N-methyl-D-aspartate (NMDA) receptors and their phosphorylation by cyclic AMP were studied as a mechanism contributing to excitotoxic vulnerability in striatal projection neurons that would lose voltage regulation after diminished K+ channels. NR1 subunits showed significant elevation in the HD transgenic projection systems but were expressed at very low levels in LAN. NR1 subunit phosphorylation by cyclic AMP also was enhanced in striatal projection neurons but not in LAN. Cyclic AMP-driven phosphorylation of NMDA receptors increases the channel open time and elevates neuronal glutamate responsiveness, which may lead to excitotoxicity. Together our data suggest that changes in these proteins and their modification may predispose striatal projection neurons to dysfunction and then degeneratation in HD and provide a mechanism for LAN resistance in the disease.

    Funded by: NINDS NIH HHS: NS41574

    Journal of neuroscience research 2005;80;5;634-45

  • Wnk1 kinase deficiency lowers blood pressure in mice: a gene-trap screen to identify potential targets for therapeutic intervention.

    Zambrowicz BP, Abuin A, Ramirez-Solis R, Richter LJ, Piggott J, BeltrandelRio H, Buxton EC, Edwards J, Finch RA, Friddle CJ, Gupta A, Hansen G, Hu Y, Huang W, Jaing C, Key BW, Kipp P, Kohlhauff B, Ma ZQ, Markesich D, Payne R, Potter DG, Qian N, Shaw J, Schrick J, Shi ZZ, Sparks MJ, Van Sligtenhorst I, Vogel P, Walke W, Xu N, Zhu Q, Person C and Sands AT

    Lexicon Genetics, 8800 Technology Forest Place, The Woodlands, TX 77381, USA. brian@lexgen.com

    The availability of both the mouse and human genome sequences allows for the systematic discovery of human gene function through the use of the mouse as a model system. To accelerate the genetic determination of gene function, we have developed a sequence-tagged gene-trap library of >270,000 mouse embryonic stem cell clones representing mutations in approximately 60% of mammalian genes. Through the generation and phenotypic analysis of knockout mice from this resource, we are undertaking a functional screen to identify genes regulating physiological parameters such as blood pressure. As part of this screen, mice deficient for the Wnk1 kinase gene were generated and analyzed. Genetic studies in humans have shown that large intronic deletions in WNK1 lead to its overexpression and are responsible for pseudohypoaldosteronism type II, an autosomal dominant disorder characterized by hypertension, increased renal salt reabsorption, and impaired K+ and H+ excretion. Consistent with the human genetic studies, Wnk1 heterozygous mice displayed a significant decrease in blood pressure. Mice homozygous for the Wnk1 mutation died during embryonic development before day 13 of gestation. These results demonstrate that Wnk1 is a regulator of blood pressure critical for development and illustrate the utility of a functional screen driven by a sequence-based mutagenesis approach.

    Proceedings of the National Academy of Sciences of the United States of America 2003;100;24;14109-14

  • Inward rectifier K+ channel Kir2.3 is localized at the postsynaptic membrane of excitatory synapses.

    Inanobe A, Fujita A, Ito M, Tomoike H, Inageda K and Kurachi Y

    Department of Pharmacology II, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan.

    Classical inwardly rectifying K+ channels (Kir2.0) are responsible for maintaining the resting membrane potential near the K+ equilibrium potential in various cells, including neurons. Although Kir2.3 is known to be expressed abundantly in the forebrain, its precise localization has not been identified. Using an antibody specific to Kir2.3, we examined the subcellular localization of Kir2.3 in mouse brain. Kir2.3 immunoreactivity was detected in a granular pattern in restricted areas of the brain, including the olfactory bulb (OB). Immunoelectron microscopy of the OB revealed that Kir2.3 immunoreactivity was specifically clustered on the postsynaptic membrane of asymmetric synapses between granule cells and mitral/tufted cells. The immunoprecipitants for Kir2.3 obtained from brain contained PSD-95 and chapsyn-110, PDZ domain-containing anchoring proteins. In vitro binding assay further revealed that the COOH-terminal end of Kir2.3 is responsible for the association with these anchoring proteins. Therefore, the Kir channel may be involved in formation of the resting membrane potential of the spines and, thus, would affect the response of N-methyl-D-aspartic acid receptor channels at the excitatory postsynaptic membrane.

    American journal of physiology. Cell physiology 2002;282;6;C1396-403

  • High-throughput sequence identification of gene coding variants within alcohol-related QTLs.

    Ehringer MA, Thompson J, Conroy O, Xu Y, Yang F, Canniff J, Beeson M, Gordon L, Bennett B, Johnson TE and Sikela JM

    Department of Pharmacology, University of Colorado Health Sciences Center, 4200 East Ninth Ave., Denver, Colorado 80262, USA.

    Low initial response to alcohol has been shown to be among the best predictors of development of alcoholism. A similar phenotypic measure, difference in initial sensitivity to ethanol, has been used for the genetic selection of two mouse strains, the Inbred Long-Sleep (ILS) and Inbred Short-Sleep (ISS) mice, and for the subsequent identification of four quantitative trait loci (QTLs) for alcohol sensitivity. We now report the application of high throughput comparative gene sequencing in the search for genes underlying these four QTLs. To carry out this search, over 1.7 million bases of comparative DNA sequence were generated from 68 candidate genes within the QTL intervals, corresponding to a survey of over 36,000 amino acids. Eight central nervous system genes, located within these QTLs, were identified that contain a total of 36 changes in protein coding sequence. Some of these coding variants are likely to contribute to the phenotypic variation between ILS/ISS animals, including sensitivity to alcohol, providing specific new genetic targets potentially important to the neuronal actions of alcohol.

    Funded by: NIAAA NIH HHS: 5 P50 AA03527, R01 AA08940, R01 AA11853, R02 AA00195; NIMH NIH HHS: MH16880-20

    Mammalian genome : official journal of the International Mammalian Genome Society 2001;12;8;657-63

  • Mapping a gene for neuropathic pain-related behavior following peripheral neurectomy in the mouse.

    Seltzer Z, Wu T, Max MB and Diehl SR

    Department of Physiology, Faculties of Medicine and Dental Medicine, Hebrew University, P.O. Box 11720, 91120 Jerusalem, Israel.

    Total hindpaw denervation in rodents elicits an abnormal behavior of licking, scratching and self-injury of the anesthetic limb ("autotomy"). Since the same denervation produces phantom limb pain and anesthesia dolorosa in humans, autotomy has been used as a model of human neuropathic pain. Autotomy is an inherited trait in rodents, attributable to a few genes of major effect. Here we used recombinant inbred (RI) mouse lines of the AXB-BXA RI set to map a gene for autotomy. Autotomy levels following unilateral sciatic and saphenous nerve section were scored daily for 36 days, using a standardized scale, in all 23 RI lines available for this set. We used a genetic map of 395 marker loci and a permutation-based statistical method for categorical data to assess the statistical significance of mapping results. We identified a marker on chromosome 15 with statistical support (P=0.0003) in the range considered significant for genome-wide scans in the mouse. Several genes located in this chromosomal region encode for neural functions related to neuropathic pain and may indicate targets for development of novel analgesics.

    Pain 2001;93;2;101-6

  • Ethanol opens G-protein-activated inwardly rectifying K+ channels.

    Kobayashi T, Ikeda K, Kojima H, Niki H, Yano R, Yoshioka T and Kumanishi T

    Department of Molecular Neuropathology, Brain Research Institute, Niigata University, 1-757 Asahimachi, Niigata, Niigata 951-8585, Japan. kobato@bri.niigata-u.ac.jp

    Ethanol affects many functions of the brain and peripheral organs. Here we show that ethanol opens G-protein-activated, inwardly rectifying K + (GIRK) channels, which has important implications for inhibitory regulation of neuronal excitability and heart rate. At pharmacologically relevant concentrations, ethanol activated both brain-type GIRK1/2 and cardiac-type GIRK1/4 channels without interaction with G proteins or second messengers. Moreover, weaver mutant mice, which have a missense mutation in the GIRK2 channel, showed a loss of ethanol-induced analgesia. These results suggest that the GIRK channels in the brain and heart are important target sites for ethanol.

    Nature neuroscience 1999;2;12;1091-7

  • Neuronal interleukin-16 (NIL-16): a dual function PDZ domain protein.

    Kurschner C and Yuzaki M

    Department of Developmental Neurobiology, Saint Jude Children's Research Hospital, Memphis, Tennessee 38105, USA.

    Interleukin (IL)-16 is a proinflammatory cytokine that has attracted widespread attention because of its ability to block HIV replication. We describe the identification and characterization of a large neuronal IL-16 precursor, NIL-16. The N-terminal half of NIL-16 constitutes a novel PDZ domain protein sequence, whereas the C terminus is identical with splenocyte-derived mouse pro-IL-16. IL-16 has been characterized only in the immune system, and the identification of NIL-16 marks a previously unsuspected connection between the immune and the nervous systems. NIL-16 is a cytosolic protein that is detected only in neurons of the cerebellum and the hippocampus. The N-terminal portion of NIL-16 interacts selectively with a variety of neuronal ion channels, which is similar to the function of many other PDZ domain proteins that serve as intracellular scaffolding proteins. Among the NIL-16-interacting proteins is the class C alpha1 subunit of a mouse brain calcium channel (mbC alpha1). The C terminus of NIL-16 can be processed by caspase-3, resulting in the release of secreted IL-16. Furthermore, in cultured cerebellar granule neurons undergoing apoptosis, NIL-16 proteolysis parallels caspase-3 activation. Cerebellar granule neurons express the IL-16 receptor CD4. Exposure of these cells to IL-16 induces expression of the immediate-early gene, c-fos, via a signaling pathway that involves tyrosine phosphorylation. This suggests that IL-16 provides an autocrine function in the brain. Therefore, we hypothesize that NIL-16 is a dual function protein in the nervous system that serves as a secreted signaling molecule as well as a scaffolding protein.

    Funded by: NCI NIH HHS: P30 CA21765

    The Journal of neuroscience : the official journal of the Society for Neuroscience 1999;19;18;7770-80

  • Comparative analyses of the Dominant megacolon-SOX10 genomic interval in mouse and human.

    Southard-Smith EM, Collins JE, Ellison JS, Smith KJ, Baxevanis AD, Touchman JW, Green ED, Dunham I and Pavan WJ

    Genetic Disease Research Branch, National Human Genome Research Institute, National Institutes of Health, 49 Convent Dr., Bethesda, Maryland 20892-4470, USA.

    Funded by: Wellcome Trust

    Mammalian genome : official journal of the International Mammalian Genome Society 1999;10;7;744-9

  • Assignment of the murine inwardly rectifying potassium channel IRK3 gene (Kcnj4) to the mouse chromosome 15.

    Morishige K, Takumi T, Takahashi N, Koyama H, Kurachi H, Miyake A, Murata Y, Copeland NG, Gilbert DJ, Jenkins NA and Kurachi Y

    Department of Pharmacology II, Faculty of Medicine, Osaka University, Suita, Osaka 565, Japan.

    Mammalian genome : official journal of the International Mammalian Genome Society 1997;8;9;699-700

  • Murine Hn1 on chromosome 11 is expressed in hemopoietic and brain tissues.

    Tang W, Lai YH, Han XD, Wong PM, Peters LL and Chui DH

    Department of Pathology, McMaster University School of Medicine, 1200 Main Street West, Hamilton, Ontario, Canada L8N 3Z5.

    Funded by: NHLBI NIH HHS: HL55321, R01 HL055321

    Mammalian genome : official journal of the International Mammalian Genome Society 1997;8;9;695-6

  • Identification and molecular localization of a pH-sensing domain for the inward rectifier potassium channel HIR.

    Coulter KL, Périer F, Radeke CM and Vandenberg CA

    Department of Biological Sciences, University of California, Santa Barbara 93106, USA.

    Inward rectifier potassium channels are found in the heart and CNS, where they are critical for the modulation and maintenance of cellular excitability. We present evidence that the inward rectifier potassium channel HIR is modulated by extracellular pH in the physiological range. We show that proton-induced changes in HIR single-channel conductance underlie the HIR pH sensitivity seen on the macroscopic level. We used chimeric and mutant channels to localize the molecular determinant of HIR pH sensitivity to a single residue, H117, in the M1-to-H5 linker region. This residue provides a molecular context that allows a titratable group to influence pore properties. We present evidence that this titratable group is one of two cysteines located in the M1-to-H5 and H5-to-M2 linkers.

    Funded by: NHLBI NIH HHS: HL41656

    Neuron 1995;15;5;1157-68

  • The inward rectifier potassium channel family.

    Doupnik CA, Davidson N and Lester HA

    Division of Biology, California Institute of Technology, Pasadena 91125, USA.

    Recent cloning of a family of genes encoding inwardly rectifying K+ channels has provided the opportunity to explain some venerable problems in membrane biology. An expanding number of novel inwardly rectifying K+ channel clones has revealed multiple channel subfamilies that have specialized roles in cell function. The molecular determinants of inward rectification have been largely elucidated with the discovery of endogenous polyamines that act as voltage-dependent intracellular channel blockers, and with the identification of a critical site in the channel that mediates high-affinity block by both polyamines and Mg2+.

    Current opinion in neurobiology 1995;5;3;268-77

  • Cloning provides evidence for a family of inward rectifier and G-protein coupled K+ channels in the brain.

    Lesage F, Duprat F, Fink M, Guillemare E, Coppola T, Lazdunski M and Hugnot JP

    Institut de Pharmacologie Moléculaire et Cellulaire, CNRS, Valbonne, France.

    MbIRK3, mbGIRK2 and mbGIRK3 K+ channels cDNAs have been cloned from adult mouse brain. These cDNAs encode polypeptides of 445, 414 and 376 amino acids, respectively, which display the hallmarks of inward rectifier K+ channels, i.e. two hydrophobic membrane-spanning domains M1 and M2 and a pore-forming domain H5. MbIRK3 shows around 65% amino acid identity with IRK1 and rbIRK2 and only 50% with ROMK1 and GIRK1. On the other hand, mbGIRK2 and mbGIRK3 are more similar to GIRK1 (60%) than to ROMK1 and IRK1 (50%). Northern blot analysis reveals that these three novel clones are mainly expressed in the brain. Xenopus oocytes injected with mbIRK3 and mbGIRK2 cRNAs display inward rectifier K(+)-selective currents very similar to IRK1 and GIRK1, respectively. As expected from the sequence homology, mbGIRK2 cRNA directs the expression of G-protein coupled inward rectifier K+ channels which has been observed through their functional coupling with co-expressed delta-opioid receptors. These results provide the first evidence that the GIRK family, as the IRK family, is composed of multiple genes with members specifically expressed in the nervous system.

    FEBS letters 1994;353;1;37-42

  • Molecular cloning and functional expression of cDNA encoding a second class of inward rectifier potassium channels in the mouse brain.

    Takahashi N, Morishige K, Jahangir A, Yamada M, Findlay I, Koyama H and Kurachi Y

    Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota 55905.

    We have cloned a second class of inward rectifier potassium channels, designated MB-IRK2, from a mouse brain cDNA library. The amino acid sequence of this clone shares 70% identity with the mouse IRK1. Xenopus oocytes injected with cRNA derived from MB-IRK2 expressed a K+ current, which showed inward rectifying channel characteristics similar to the MB-IRK1 current. In contrast to the MB-IRK1 current, however, the MB-IRK2 current exhibited significant inactivation during hyperpolarizing pulses. In patch clamp experiments with 140 mM K+ in the pipette, the single channel conductance of MB-IRK2 was 34.2 +/- 2.1 picosiemens (n = 5), a value significantly larger than that of MB-IRK1 (22.2 +/- 3.0 picosiemens, n = 5). Consistent with the whole cell current, the steady-state open probability (Po) of the MB-IRK2 channel decreased with hyperpolarization, whereas that of the MB-IRK1 remained constant. Northern blot analysis revealed the mRNA for MB-IRK2 to be expressed in forebrain, cerebellum, heart, kidney, and skeletal muscle. In the brain, the abundance of mRNA for MB-IRK2 was much higher in cerebellum than in forebrain and vice versa in the case of MB-IRK1. These results demonstrate that the IRK family is composed of multiple genes, which may play heterogenous functional roles in various organs, including the central nervous system.

    Funded by: NHLBI NIH HHS: R01 HL47360

    The Journal of biological chemistry 1994;269;37;23274-9

  • Molecular cloning and functional expression of a novel brain-specific inward rectifier potassium channel.

    Morishige K, Takahashi N, Jahangir A, Yamada M, Koyama H, Zanelli JS and Kurachi Y

    Department of Internal Medicine, Mayo Clinic, Rochester, MN 55905.

    We have cloned a novel brain-specific inward rectifier K+ channel from a mouse brain cDNA library and designated it MB-IRK3. The mouse brain cDNA library was screened using a fragment of the mouse macrophage inward rectifier K+ channel (IRK1) cDNA as a probe. The amino acid sequence of MB-IRK3 shares 61% and 64% identity to MB-IRK1 and RB-IRK2, respectively. Xenopus oocytes injected with cRNA derived from this clone expressed a potassium current which showed inward-rectifying channel characteristics similar to MB-IRK1 and RB-IRK2 currents, but distinct from ROMK1 or GIRK1 current. However, the single channel conductance of MB-IRK3 was approximately 10 pS with 140 mM extracellular K+, which was distinct from that of MB-IRK1 (20 pS). MB-IRK3 mRNA expressed specifically in the forebrain, which clearly differed from MB-IRK1 and RB-IRK2 mRNAs. These results indicate that members of the IRK family with distinct electrophysiological properties express differentially and may play heterogenous functional roles in brain functions.

    Funded by: NHLBI NIH HHS: R01 HL47360

    FEBS letters 1994;346;2-3;251-6

Gene lists (3)

Gene List Source Species Name Description Gene count
L00000001 G2C Mus musculus Mouse PSD Mouse PSD adapted from Collins et al (2006) 1080
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
© 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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