TY - JOUR A1 - Davis, Lea K. A1 - Yu, Dongmei A1 - Keenan, Clare L. A1 - Gamazon, Eric R. A1 - Konkashbaev, Anuar I. A1 - Derks, Eske M. A1 - Neale, Benjamin M. A1 - Yang, Jian A1 - Lee, S. Hong A1 - Evans, Patrick A1 - Barr, Cathy L. A1 - Bellodi, Laura A1 - Benarroch, Fortu A1 - Berrio, Gabriel Bedoya A1 - Bienvenu, Oscar J. A1 - Bloch, Michael H. A1 - Blom, Rianne M. A1 - Bruun, Ruth D. A1 - Budman, Cathy L. A1 - Camarena, Beatriz A1 - Campbell, Desmond A1 - Cappi, Carolina A1 - Cardona Silgado, Julio C. A1 - Cath, Danielle C. A1 - Cavallini, Maria C. A1 - Chavira, Denise A. A1 - Chouinard, Sylvian A1 - Conti, David V. A1 - Cook, Edwin H. A1 - Coric, Vladimir A1 - Cullen, Bernadette A. A1 - Deforce, Dieter A1 - Delorme, Richard A1 - Dion, Yves A1 - Edlund, Christopher K. A1 - Egberts, Karin A1 - Falkai, Peter A1 - Fernandez, Thomas V. A1 - Gallagher, Patience J. A1 - Garrido, Helena A1 - Geller, Daniel A1 - Girard, Simon L. A1 - Grabe, Hans J. A1 - Grados, Marco A. A1 - Greenberg, Benjamin D. A1 - Gross-Tsur, Varda A1 - Haddad, Stephen A1 - Heiman, Gary A. A1 - Hemmings, Sian M. J. A1 - Hounie, Ana G. A1 - Illmann, Cornelia A1 - Jankovic, Joseph A1 - Jenike, Micheal A. A1 - Kennedy, James L. A1 - King, Robert A. A1 - Kremeyer, Barbara A1 - Kurlan, Roger A1 - Lanzagorta, Nuria A1 - Leboyer, Marion A1 - Leckman, James F. A1 - Lennertz, Leonhard A1 - Liu, Chunyu A1 - Lochner, Christine A1 - Lowe, Thomas L. A1 - Macciardi, Fabio A1 - McCracken, James T. A1 - McGrath, Lauren M. A1 - Restrepo, Sandra C. Mesa A1 - Moessner, Rainald A1 - Morgan, Jubel A1 - Muller, Heike A1 - Murphy, Dennis L. A1 - Naarden, Allan L. A1 - Ochoa, William Cornejo A1 - Ophoff, Roel A. A1 - Osiecki, Lisa A1 - Pakstis, Andrew J. A1 - Pato, Michele T. A1 - Pato, Carlos N. A1 - Piacentini, John A1 - Pittenger, Christopher A1 - Pollak, Yehunda A1 - Rauch, Scott L. A1 - Renner, Tobias J. A1 - Reus, Victor I. A1 - Richter, Margaret A. A1 - Riddle, Mark A. A1 - Robertson, Mary M. A1 - Romero, Roxana A1 - Rosàrio, Maria C. A1 - Rosenberg, David A1 - Rouleau, Guy A. A1 - Ruhrmann, Stephan A1 - Ruiz-Linares, Andreas A1 - Sampaio, Aline S. A1 - Samuels, Jack A1 - Sandor, Paul A1 - Sheppard, Broke A1 - Singer, Harvey S. A1 - Smit, Jan H. A1 - Stein, Dan J. A1 - Strengman, E. A1 - Tischfield, Jay A. A1 - Valencia Duarte, Ana V. A1 - Vallada, Homero A1 - Van Nieuwerburgh, Flip A1 - Veenstra-VanderWeele, Jeremy A1 - Walitza, Susanne A1 - Wang, Ying A1 - Wendland, Jens R. A1 - Westenberg, Herman G. M. A1 - Shugart, Yin Yao A1 - Miguel, Euripedes C. A1 - McMahon, William A1 - Wagner, Michael A1 - Nicolini, Humberto A1 - Posthuma, Danielle A1 - Hanna, Gregory L. A1 - Heutink, Peter A1 - Denys, Damiaan A1 - Arnold, Paul D. A1 - Oostra, Ben A. A1 - Nestadt, Gerald A1 - Freimer, Nelson B. A1 - Pauls, David L. A1 - Wray, Naomi R. A1 - Stewart, S. Evelyn A1 - Mathews, Carol A. A1 - Knowles, James A. A1 - Cox, Nancy J. A1 - Scharf, Jeremiah M. T1 - Partitioning the Heritability of Tourette Syndrome and Obsessive Compulsive Disorder Reveals Differences in Genetic Architecture JF - PLoS Genetics N2 - The direct estimation of heritability from genome-wide common variant data as implemented in the program Genome-wide Complex Trait Analysis (GCTA) has provided a means to quantify heritability attributable to all interrogated variants. We have quantified the variance in liability to disease explained by all SNPs for two phenotypically-related neurobehavioral disorders, obsessive-compulsive disorder (OCD) and Tourette Syndrome (TS), using GCTA. Our analysis yielded a heritability point estimate of 0.58 (se = 0.09, p = 5.64e-12) for TS, and 0.37 (se = 0.07, p = 1.5e-07) for OCD. In addition, we conducted multiple genomic partitioning analyses to identify genomic elements that concentrate this heritability. We examined genomic architectures of TS and OCD by chromosome, MAF bin, and functional annotations. In addition, we assessed heritability for early onset and adult onset OCD. Among other notable results, we found that SNPs with a minor allele frequency of less than 5% accounted for 21% of the TS heritability and 0% of the OCD heritability. Additionally, we identified a significant contribution to TS and OCD heritability by variants significantly associated with gene expression in two regions of the brain (parietal cortex and cerebellum) for which we had available expression quantitative trait loci (eQTLs). Finally we analyzed the genetic correlation between TS and OCD, revealing a genetic correlation of 0.41 (se = 0.15, p = 0.002). These results are very close to previous heritability estimates for TS and OCD based on twin and family studies, suggesting that very little, if any, heritability is truly missing (i.e., unassayed) from TS and OCD GWAS studies of common variation. The results also indicate that there is some genetic overlap between these two phenotypically-related neuropsychiatric disorders, but suggest that the two disorders have distinct genetic architectures. KW - TIC disorders KW - missing heritability KW - complex diseases KW - neuropsychiatric disorders KW - common SNPS KW - gilles KW - family KW - brain KW - expression KW - autism Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-127377 SN - 1553-7390 VL - 9 IS - 10 ER - TY - JOUR A1 - Schaefer, Natascha A1 - Zheng, Fang A1 - van Brederode, Johannes A1 - Berger, Alexandra A1 - Leacock, Sophie A1 - Hirata, Hiromi A1 - Paige, Christopher J. A1 - Harvey, Robert J. A1 - Alzheimer, Christian A1 - Villmann, Carmen T1 - Functional Consequences of the Postnatal Switch From Neonatal to Mutant Adult Glycine Receptor α1 Subunits in the Shaky Mouse Model of Startle Disease JF - Frontiers in Molecular Neuroscience N2 - Mutations in GlyR α1 or β subunit genes in humans and rodents lead to severe startle disease characterized by rigidity, massive stiffness and excessive startle responses upon unexpected tactile or acoustic stimuli. The recently characterized startle disease mouse mutant shaky carries a missense mutation (Q177K) in the β8-β9 loop within the large extracellular N-terminal domain of the GlyR α1 subunit. This results in a disrupted hydrogen bond network around K177 and faster GlyR decay times. Symptoms in mice start at postnatal day 14 and increase until premature death of homozygous shaky mice around 4–6 weeks after birth. Here we investigate the in vivo functional effects of the Q177K mutation using behavioral analysis coupled to protein biochemistry and functional assays. Western blot analysis revealed GlyR α1 subunit expression in wild-type and shaky animals around postnatal day 7, a week before symptoms in mutant mice become obvious. Before 2 weeks of age, homozygous shaky mice appeared healthy and showed no changes in body weight. However, analysis of gait and hind-limb clasping revealed that motor coordination was already impaired. Motor coordination and the activity pattern at P28 improved significantly upon diazepam treatment, a pharmacotherapy used in human startle disease. To investigate whether functional deficits in glycinergic neurotransmission are present prior to phenotypic onset, we performed whole-cell recordings from hypoglossal motoneurons (HMs) in brain stem slices from wild-type and shaky mice at different postnatal stages. Shaky homozygotes showed a decline in mIPSC amplitude and frequency at P9-P13, progressing to significant reductions in mIPSC amplitude and decay time at P18-24 compared to wild-type littermates. Extrasynaptic GlyRs recorded by bath-application of glycine also revealed reduced current amplitudes in shaky mice compared to wild-type neurons, suggesting that presynaptic GlyR function is also impaired. Thus, a distinct, but behaviorally ineffective impairment of glycinergic synapses precedes the symptoms onset in shaky mice. These findings extend our current knowledge on startle disease in the shaky mouse model in that they demonstrate how the progression of GlyR dysfunction causes, with a delay of about 1 week, the appearance of disease symptoms. KW - glycine receptor KW - startle disease KW - β8-β9 loop KW - mouse model KW - fast decay Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-196056 SN - 1662-5099 VL - 11 IS - 167 ER - TY - JOUR A1 - Agarwal, Shailesh R. A1 - Yang, Pei-Chi A1 - Rice, Monica A1 - Singer, Cherie A. A1 - Nikolaev, Viacheslav O. A1 - Lohse, Martin J. A1 - Clancy, Colleen E. A1 - Harvey, Robert D. T1 - Role of Membrane Microdomains in Compartmentation of cAMP Signaling JF - PLOS ONE N2 - Spatially restricting cAMP production to discrete subcellular locations permits selective regulation of specific functional responses. But exactly where and how cAMP signaling is confined is not fully understood. Different receptors and adenylyl cyclase isoforms responsible for cAMP production are not uniformly distributed between lipid raft and non-lipid raft domains of the plasma membrane. We sought to determine the role that these membrane domains play in organizing cAMP responses in HEK293 cells. The freely diffusible FRET-based biosensor Epac2-camps was used to measure global cAMP responses, while versions of the probe targeted to lipid raft (Epac2-MyrPalm) and non-raft (Epac2-CAAX) domains were used to monitor local cAMP production near the plasma membrane. Disruption of lipid rafts by cholesterol depletion selectively altered cAMP responses produced by raft-associated receptors. The results indicate that receptors associated with lipid raft as well as non-lipid raft domains can contribute to global cAMP responses. In addition, basal cAMP activity was found to be significantly higher in non-raft domains. This was supported by the fact that pharmacologic inhibition of adenylyl cyclase activity reduced basal cAMP activity detected by Epac2-CAAX but not Epac2-MyrPalm or Epac2-camps. Responses detected by Epac2-CAAX were also more sensitive to direct stimulation of adenylyl cyclase activity, but less sensitive to inhibition of phosphodiesterase activity. Quantitative modeling was used to demonstrate that differences in adenylyl cyclase and phosphodiesterase activities are necessary but not sufficient to explain compartmentation of cAMP associated with different microdomains of the plasma membrane. KW - protein-coupled-receptors KW - adenylyl-cyclase isoforms KW - adult cardiac myocytes KW - plasma membrane KW - lipid rafts KW - cholesterol depletion KW - BETA(2)-adrenergic receptor KW - living vells KW - cyclic-AMP KW - domains Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-116673 SN - 1932-6203 VL - 9 IS - 4 ER - TY - JOUR A1 - Piro, Inken A1 - Eckes, Anna-Lena A1 - Kasaragod, Vikram Babu A1 - Sommer, Claudia A1 - Harvey, Robert J. A1 - Schaefer, Natascha A1 - Villmann, Carmen T1 - Novel Functional Properties of Missense Mutations in the Glycine Receptor β Subunit in Startle Disease JF - Frontiers in Molecular Neuroscience N2 - Startle disease is a rare disorder associated with mutations in GLRA1 and GLRB, encoding glycine receptor (GlyR) α1 and β subunits, which enable fast synaptic inhibitory transmission in the spinal cord and brainstem. The GlyR β subunit is important for synaptic localization via interactions with gephyrin and contributes to agonist binding and ion channel conductance. Here, we have studied three GLRB missense mutations, Y252S, S321F, and A455P, identified in startle disease patients. For Y252S in M1 a disrupted stacking interaction with surrounding aromatic residues in M3 and M4 is suggested which is accompanied by an increased EC\(_{50}\) value. By contrast, S321F in M3 might stabilize stacking interactions with aromatic residues in M1 and M4. No significant differences in glycine potency or efficacy were observed for S321F. The A455P variant was not predicted to impact on subunit folding but surprisingly displayed increased maximal currents which were not accompanied by enhanced surface expression, suggesting that A455P is a gain-of-function mutation. All three GlyR β variants are trafficked effectively with the α1 subunit through intracellular compartments and inserted into the cellular membrane. In vivo, the GlyR β subunit is transported together with α1 and the scaffolding protein gephyrin to synaptic sites. The interaction of these proteins was studied using eGFP-gephyrin, forming cytosolic aggregates in non-neuronal cells. eGFP-gephyrin and β subunit co-expression resulted in the recruitment of both wild-type and mutant GlyR β subunits to gephyrin aggregates. However, a significantly lower number of GlyR β aggregates was observed for Y252S, while for mutants S321F and A455P, the area and the perimeter of GlyR β subunit aggregates was increased in comparison to wild-type β. Transfection of hippocampal neurons confirmed differences in GlyR-gephyrin clustering with Y252S and A455P, leading to a significant reduction in GlyR β-positive synapses. Although none of the mutations studied is directly located within the gephyrin-binding motif in the GlyR β M3-M4 loop, we suggest that structural changes within the GlyR β subunit result in differences in GlyR β-gephyrin interactions. Hence, we conclude that loss- or gain-of-function, or alterations in synaptic GlyR clustering may underlie disease pathology in startle disease patients carrying GLRB mutations. KW - glycine receptor KW - hyperekplexia KW - startle disease KW - gephyrin Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-246676 SN - 1662-5099 VL - 14 ER - TY - JOUR A1 - Drehmann, Paul A1 - Milanos, Sinem A1 - Schaefer, Natascha A1 - Kasaragod, Vikram Babu A1 - Herterich, Sarah A1 - Holzbach-Eberle, Ulrike A1 - Harvey, Robert J. A1 - Villmann, Carmen T1 - Dual role of dysfunctional Asc-1 transporter in distinct human pathologies, human startle disease, and developmental delay JF - eNeuro N2 - Human startle disease is associated with mutations in distinct genes encoding glycine receptors, transporters or interacting proteins at glycinergic synapses in spinal cord and brainstem. However, a significant number of diagnosed patients does not carry a mutation in the common genes GLRA1, GLRB, and SLC6A5. Recently, studies on solute carrier 7 subfamily 10 (SLC7A10; Asc-1, alanine-serine-cysteine transporter) knock-out (KO) mice displaying a startle disease-like phenotype hypothesized that this transporter might represent a novel candidate for human startle disease. Here, we screened 51 patients from our patient cohort negative for the common genes and found three exonic (one missense, two synonymous), seven intronic, and single nucleotide changes in the 5′ and 3′ untranslated regions (UTRs) in Asc-1. The identified missense mutation Asc-1\(^{G307R}\) from a patient with startle disease and developmental delay was investigated in functional studies. At the molecular level, the mutation Asc-1\(^{G307R}\) did not interfere with cell-surface expression, but disrupted glycine uptake. Substitution of glycine at position 307 to other amino acids, e.g., to alanine or tryptophan did not affect trafficking or glycine transport. By contrast, G307K disrupted glycine transport similar to the G307R mutation found in the patient. Structurally, the disrupted function in variants carrying positively charged residues can be explained by local structural rearrangements because of the large positively charged side chain. Thus, our data suggest that SLC7A10 may represent a rare but novel gene associated with human startle disease and developmental delay. KW - Asc-1 transporter KW - candidate gene KW - glycine receptor KW - glycine uptake KW - human startle disease KW - NMDAR Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-349947 VL - 10 IS - 11 ER -