Norman Nash - Academia.edu (original) (raw)

Papers by Norman Nash

J Neurochem, 2002

Nine isoforms of the rat NMDAR1 receptor subunit have been previously identified, of which severa... more Nine isoforms of the rat NMDAR1 receptor subunit have been previously identified, of which several have an alternatively spliced N-terminal insert believed to be important in proton sensitivity of the receptor. The cloning of the human homologues of NMDAR1 -3b (hNMDA1 -1) and NMDAR1-4b (hNMDA1-2), both bearing the insert, is reported here. A monoclonal antibody generated against the N-terminal region of these isoforms showed reactivity with at least two distinct human brain proteins of 115 kDa. This antibody was further characterized by using a series of truncated fusion proteins and splice variants of NMDAR1 demonstrating its specific recognilion of an epitope within the 21-amino acid N-terminal insert, encoded by exon 5. Western blot and immunocytochemical studies were performed to examine the expression of the exon 5-containing isoforms of the NMDAR1 subunit in both rat and human brain. Key Words: NMDAR1 -Exon 5-Monoclonal antibody.

Proceedings of the National Academy of Sciences of the United States of America, Sep 12, 1995

The Huntington disease (HD) phenotype is associated with expansion of a trinucleotide repeat in t... more The Huntington disease (HD) phenotype is associated with expansion of a trinucleotide repeat in the IT15 gene, which is predicted to encode a 348-kDa protein named huntington. We used polyclonal and monoclonal anti-fusion protein antibodies to identify native huntingtin in rat, monkey, and human. Western blots revealed a protein with the expected molecular weight which is present in the soluble fraction of rat and monkey brain tissues and lymphoblastoid cells from control cases. In lymphoblastoid cell lines from juvenile-onset heterozygote HD cases, both normal and mutant huntingtin are expressed, and increasing repeat expansion leads to lower levels of the mutant protein. Immunocytochemistry indicates that huntingtin is located in neurons throughout the brain, with the highest levels evident in larger neurons. In the human striatum, huntingtin is enriched in a patch-like distribution, potentially corresponding to the first areas affected in HD. Subcellular localization of huntingtin is consistent with a cytosolic protein primarily found in somatodendritic regions. Huntingtin appears to particularly associate with microtubules, although some is also associated with synaptic vesicles. On the basis of the localization of huntingtin in association with microtubules, we speculate that the mutation impairs the cytoskeletal anchoring or transport of mitochondria, vesicles, or other organelles or molecules.

The Journal of Neuroscience the Official Journal of the Society For Neuroscience, Apr 1, 1996

Current Pharmaceutical Design, Feb 1, 2006

Chemical genomics is a drug discovery strategy that relies heavily on high-throughput screening (... more Chemical genomics is a drug discovery strategy that relies heavily on high-throughput screening (HTS) and therefore benefits from functional assay platforms that allow HTS against all relevant genomic targets. Receptor Selection and Amplification Technology (R-SAT) is a cell-based, high-throughput functional assay where the receptor stimulus is translated into a measurable cellular response through an extensive signaling cascade occurring over several days. The large biological and chronological separation of stimulus from response provides numerous opportunities for enabling assays and increasing assay sensitivity. Here we review strategies for building homogeneous assay platforms across large gene families by redirecting and/or amplifying signal transduction pathways.

The Journal of Neuroscience the Official Journal of the Society For Neuroscience, Mar 15, 1997

Several genes have been implicated in the pathogenesis of early-onset familial Alzheimer's diseas... more Several genes have been implicated in the pathogenesis of early-onset familial Alzheimer's disease. A majority of the autosomal dominant cases are linked to recently identified mutations in the presenilin-1 gene on chromosome 14. The native presenilin-1 protein in primates has not been well characterized, and its precise localization is unknown. We have studied the native presenilin-1 protein in monkey brain and peripheral tissues by using a monoclonal antibody specific for the N-terminal domain of human presenilin-1. Western blots detect polypeptide species of ϳ49 and ϳ32 kDa from COS-7 and PC12 cells transfected with full-length human presenilin-1 cDNA and from in vitro translations of the normal human presenilin-1 mRNA. A 32 kDa polypeptide is detected in monkey peripheral tissues, with the highest expression in testis and lung. In all brain regions the 32 kDa band is the predominant form of presenilin-1, and it is found in particulate subfractions. Light microscopic immunocytochemistry reveals presenilin-1 staining in all brain regions, with the strongest labeling in neurons and neuropil. In addition, weaker immunoreactivity is also present in glia and blood vessels. Neuronal staining shows significant variability, with particularly intense labeling of certain cell types, including large neocortical and hippocampal pyramidal neurons, magnocellular basal forebrain neurons, brainstem motoneurons, and some populations of interneurons. By electron microscopic immunocytochemistry, highly selective presenilin-1 staining is seen on the cytoplasmic surfaces of membranous organelles, which suggest localization to the endoplasmic reticulum-Golgi intermediate compartment, a subdomain of the endoplasmic reticulum, and some coated transport vesicles.

The Journal of neuroscience : the official journal of the Society for Neuroscience, 1996

A cholinergic locus has recently been identified consisting of a unique mammalian genomic arrange... more A cholinergic locus has recently been identified consisting of a unique mammalian genomic arrangement containing the genes for choline acetyltransferase (ChAT) and a putative vesicular acetylcholine transporter (VAChT). Although transcripts for ChAT and VAChT protein have been localized in cholinergic neurons, little is known about the encoded VAChT protein. Here we describe production of highly specific rabbit polyclonal antibodies, generated using a VAChT C-terminus/glutathione-S-transferase fusion protein, and immunological characterization of the native VAChT protein. These antibodies specifically recognized full-length recombinant VAChT expressed in transfected HeLa cells by Western blotting, with the prominent immunoreactive band at 55 kDa. In rat brain homogenates, a single VAChT-immunoreactive band of approximately 70 kDa was predominant in known areas of cholinergic innervation, including striatum, cortex, hippocampus,and amygdala. Light microscopic immunocytochemistry reve...

Current Protocols in Neuroscience, 2001

... Contributed by Michelle Gilmor, Craig Heilman, Norman Nash, and Allan Levey Current Protocols... more ... Contributed by Michelle Gilmor, Craig Heilman, Norman Nash, and Allan Levey Current Protocols in Neuroscience (1997) 5.7.1-5.7.17 Copyright © 1997 by ... 5. Purify the digested PCR product and vector on a low-gelling/melting temperature agarose gel and extract from the gel ...

Current Protocols in Pharmacology, 2001

American Journal of Pharmacogenomics Genomics Related Research in Drug Development and Clinical Practice, Feb 1, 2004

BACKGROUND AND OBJECTIVES: A number of recent studies surveying single nucleotide polymorphisms w... more BACKGROUND AND OBJECTIVES: A number of recent studies surveying single nucleotide polymorphisms within the exonic regions of human genes have revealed a significant number of such variants, including many non-synonymous variants. This highlights the need to directly identify, within individual clinically well-defined patients, those variants that alter protein function as well as structure. We report on the development of a novel phenotypic screening process that combines high-throughput molecular cloning techniques with functional expression utilizing the cell-based assay R-SAT.METHODS: We applied the phenotypic screening process to an analysis of the m1 muscarinic acetylcholine receptor (CHRM1) gene in a cohort of 74 individuals, including 48 diagnosed with neurodegenerative disease, primarily Alzheimer disease, who have been stratified according to their clinical response to the acetylcholinesterase inhibitor donepezil. Phenotypic screening of the CHRM1 gene involved PCR-based amplification from genomic DNA and heterologous expression in mammalian cells.RESULTS: Phenotypic screening yielded functional responses to the agonist carbachol displaying a mean potency (-pEC(50)+/- standard deviation) of 5.8 +/- 0.2, which did not differ from that observed with expression of the wild-type receptor gene (6.0 +/- 0.3). No altered levels of constitutive receptor activity were observed. Dideoxy sequencing did not reveal any non-synonymous variants in the coding exon of this gene within this clinical cohort, while detecting three synonymous variants.CONCLUSION: The results confirm that the m1 receptor gene (CHRM1) is not highly polymorphic in the human population, suggesting that genetic variation within the coding exon of this gene is not a contributing factor to the clinical variability observed during treatment of dementia with cholinergic enhancement therapies.

Several genes have been implicated in the pathogenesis of early-onset familial Alzheimer's di... more Several genes have been implicated in the pathogenesis of early-onset familial Alzheimer's disease. A majority of the au- tosomal dominant cases are linked to recently identified muta- tions in the presenilin-1 gene on chromosome 14. The native presenilin-1 protein in primates has not been well character- ized, and its precise localization is unknown. We have studied the native presenilin-1 protein

Proceedings of the National Academy of Sciences, 1995

Cytotechnology, 2002

Chemical genomics is a new research paradigm with importantapplications in drug discovery. It lin... more Chemical genomics is a new research paradigm with importantapplications in drug discovery. It links genomic targets withsmall-molecule chemistries thereby allowing for efficient targetvalidation and lead compound identification. ACADIA'schemical-genomics platform consists of a large and diverse small-moleculelibrary (800,000), a reference drug library (2,000), druggablegenomic targets (>300) and a cell-based functional assaytechnology (R-SAT(TM); Receptor Selection and AmplificationTechnology) that allows for ultra-high throughput screening(>500,000 data points/week) as well as high throughputpharmacology and profiling over a wide range of targets. Twoexamples are presented that illustrate the success of ourchemical-genomics approach: (i) The validation of inverse agonismat serotonin 5-HT(2A) receptors as an antipsychotic mechanismand the subsequent discovery of potent and selectively acting 5-HT(2A) inverse agonists, currently in preclinical development,and (ii) the disco...

Pediatric Radiology, 1991

The association of colonic diverticulitis with chronic renal failure is well known. In those pati... more The association of colonic diverticulitis with chronic renal failure is well known. In those patients with "adult" autosomal dominant polycystic kidney disease, colonic diverticulitis is an especially common complication. We present two young patients (one teenager and one mid-twenties) who developed intra-abdominal abscess several years after renal transplantation. Neither patient had autosomal dominant polycystic disease nor a known history of gastrointestinal problems but both proved to have underlying, previously unsuspected colonic diverticular disease with abscess formation.

The Journal of pharmacology and experimental therapeutics, 2008

We report the first small-molecule protease-activated receptor (PAR) 2 agonists, AC-55541 [N-[[1-... more We report the first small-molecule protease-activated receptor (PAR) 2 agonists, AC-55541 [N-[[1-(3-bromo-phenyl)-eth-(E)-ylidene-hydrazinocarbonyl]-(4-oxo-3,4-dihydro-phthalazin-1-yl)-methyl]-benzamide] and AC-264613 [2-oxo-4-phenylpyrrolidine-3-carboxylic acid [1-(3-bromo-phenyl)-(E/Z)-ethylidene]-hydrazide], each representing a distinct chemical series. AC-55541 and AC-264613 each activated PAR2 signaling in cellular proliferation assays, phosphatidylinositol hydrolysis assays, and Ca(2+) mobilization assays, with potencies ranging from 200 to 1000 nM for AC-55541 and 30 to 100 nM for AC-264613. In comparison, the PAR2-activating peptide 2-furoyl-LIGRLO-NH(2) had similar potency, whereas SLIGRL-NH(2) was 30 to 300 times less potent. Neither AC-55541 nor AC-264613 had activity at any of the other PAR receptor subtypes, nor did they have any significant affinity for over 30 other molecular targets involved in nociception. Visualization of EYFP-tagged PAR2 receptors showed that each...

Neuron, 1994

The cellular and subcellular distributions of the glutamate transporter subtypes EAAC1, GLT-1, an... more The cellular and subcellular distributions of the glutamate transporter subtypes EAAC1, GLT-1, and GLAST in the rat CNS were demonstrated using anti-peptide antibodies that recognize the C-terminal domains of each transporter. On immunoblots, the antibodies specifically ...