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The NMJ as a model synapse: New perspectives on formation, synaptic transmission and maintenance: Acetylcholinesterase at the neuromuscular junction. Neurosci Lett 2020; 735:135157. [PMID: 32540360 DOI: 10.1016/j.neulet.2020.135157] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 06/10/2020] [Accepted: 06/11/2020] [Indexed: 12/28/2022]
Abstract
Acetylcholinesterase (AChE) is an essential enzymatic component of the neuromuscular junction where it is responsible for terminating neurotransmission by the cholinergic motor neurons. The enzyme at the neuromuscular junction (NMJ) is contributed primarily by the skeletal muscle where it is produced at higher levels in the post-synaptic region of the fibers. The major form of AChE at the NMJ is a large asymmetric form consisting of three tetramers covalently attached to a three-stranded collagen-like tail which is responsible for anchoring it to the synaptic basal lamina. Its location and expression is regulated to a large extent by the motor neurons and occurs at the transcriptional, translational and post-translational levels. While its expression can be quite rapid in tissue cultured cells, its half-life in vivo appears to be quite long, about three weeks, although more rapidly turning over pools have been described. Finally the essential nature of this enzyme is underscored by the fact that no naturally occurring null mutations of the catalytic subunit have been described in higher organisms and the few dozen humans carrying mutations in the collagen tail responsible for anchoring the enzyme at the NMJ are severely affected.
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Nikitashina AD, Petrov KA, Zobov VV, Reznik VS, Nikol'skii EE. Specific inhibitory effects of the alkylammonium derivative 6-methyluracil on acetylcholinesterase of smooth and striated muscles in rats. DOKLADY BIOLOGICAL SCIENCES : PROCEEDINGS OF THE ACADEMY OF SCIENCES OF THE USSR, BIOLOGICAL SCIENCES SECTIONS 2013; 449:82-84. [PMID: 23652433 DOI: 10.1134/s0012496613020099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Indexed: 06/02/2023]
Affiliation(s)
- A D Nikitashina
- Kazan Institute of Biochemistry and Biophysics, Kazan Scientific Center, Russian Academy of Sciences, Kazan, Russia
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3
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Orso F, Jäger R, Calogero RA, Schorle H, Sismondi P, De Bortoli M, Taverna D. AP-2alpha regulates migration of GN-11 neurons via a specific genetic programme involving the Axl receptor tyrosine kinase. BMC Biol 2009; 7:25. [PMID: 19463168 PMCID: PMC2700071 DOI: 10.1186/1741-7007-7-25] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2008] [Accepted: 05/22/2009] [Indexed: 12/27/2022] Open
Abstract
Background Neuronal migration is a crucial process that allows neurons to reach their correct target location to allow the nervous system to function properly. AP-2α is a transcription factor essential for neural crest cell migration and its mutation results in apoptosis within this cell population, as demonstrated by genetic models. Results We down-modulated AP-2α expression in GN-11 neurons by RNA interference and observe reduced neuron migration following the activation of a specific genetic programme including the Adhesion Related Kinase (Axl) gene. We prove that Axl is able to coordinate migration per se and by ChIP and promoter analysis we observe that its transcription is directly driven by AP-2α via the binding to one or more functional AP-2α binding sites present in its regulatory region. Analysis of migration in AP-2α null mouse embryo fibroblasts also reveals an essential role for AP-2α in cell movement via the activation of a distinct genetic programme. Conclusion We show that AP-2α plays an essential role in cell movement via the activation of cell-specific genetic programmes. Moreover, we demonstrate that the AP-2α regulated gene Axl is an essential player in GN-11 neuron migration.
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Affiliation(s)
- Francesca Orso
- Molecular Biotechnology Center, University of Torino, via Nizza, 52, 10126, Torino, Italy.
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4
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Zhu H, Gao W, Jiang H, Jin QH, Shi YF, Tsim KWK, Zhang XJ. Regulation of acetylcholinesterase expression by calcium signaling during calcium ionophore A23187- and thapsigargin-induced apoptosis. Int J Biochem Cell Biol 2007; 39:93-108. [PMID: 17000130 DOI: 10.1016/j.biocel.2006.06.012] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2006] [Revised: 06/06/2006] [Accepted: 06/13/2006] [Indexed: 11/23/2022]
Abstract
We have recently reported that acetylcholinesterase expression was induced during apoptosis in various cell types. In the current study we provide evidence to suggest that the induction of acetylcholinesterase expression during apoptosis is regulated by the mobilization of intracellular Ca(2+). During apoptosis, treatment of HeLa and MDA-MB-435s cells with the calcium ionophore A23187 resulted in a significant increase in acetylcholinesterase mRNA and protein levels. Chelation of intracellular Ca(2+) by BAPTA-AM (1,2-bis-(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl ester), an intracellular Ca(2+) chelator, inhibited acetylcholinesterase expression. A23187 also enhanced the stability of acetylcholinesterase mRNA and increased the activity of acetylcholinesterase promoter, effects that were blocked by BAPTA-AM. Perturbations of cellular Ca(2+) homeostasis by thapsigargin resulted in the increase of acetylcholinesterase expression as well as acetylcholinesterase promoter activity during thapsigargin induced apoptosis in HeLa and MDA-MB-435s cells, effects that were also inhibited by BAPTA-AM. We further demonstrated that the transactivation of the human acetylcholinesterase promoter by A23187 and thapsigargin was partially mediated by a CCAAT motif within the -1270 to -1248 fragment of the human acetylcholinesterase promoter. This motif was able to bind to CCAAT binding factor (CBF/NF-Y). These results strongly suggest that cytosolic Ca(2+) plays a key role in acetylcholinesterase regulation during apoptosis induced by A23187 and thapsigargin.
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Affiliation(s)
- Hui Zhu
- Laboratory of Molecular Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Graduate School of the Chinese Academy of Sciences, 320 YueYang Road, Shanghai 200031, China
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5
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Cuellar H, Kim JA, Unguez GA. Evidence of post-transcriptional regulation in the maintenance of a partial muscle phenotype by electrogenic cells of S. macrurus. FASEB J 2006; 20:2540. [PMID: 17077280 DOI: 10.1096/fj.06-6474fje] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Electrocytes, the current-producing cells of electric organs (EOs) in electric fish, are unique in that they derive from striated muscle and they possess biochemical characteristics of both muscle and non-muscle cells. In the freshwater teleost Sternopygus macrurus, electrocytes are multinucleated cells that do not contract yet retain expression of some proteins common to skeletal muscle cells. Given the role that transcriptional regulation plays in the activation of the myogenic program in vertebrates, we examined the expression patterns of several genes associated with multiple functions of skeletal muscle in mature electrocytes of S. macrurus. Our expression analyses detected transcripts for alpha-actin, alpha-acetylcholine (ACh) receptor (alpha-AChR), desmin, muscle creatine kinase (MCK), myosin heavy chain (MHC) isoforms, titin, tropomyosin, and troponin-T genes in the EO. However, immunolabeling studies revealed that electrocytes do not contain MCK, MHCs, or tropomyosin or troponin-T proteins. These results underscore the contribution of gene regulatory mechanisms in the maintenance of the muscle-like phenotype of EO that may be transcriptional-independent. We also report the classification and frequency of distinct transcripts from a random selection of 420 clones from an EO cDNA library. This is the first characterization of expressed genes in an EO, and it is an important step toward identifying mechanisms that affect different muscle protein systems for the evolution of highly specialized noncontractile tissues. Evidence of post-transcriptional regulation in the maintenance of a partial muscle phenotype by electrogenic cells of S. macrurus.
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Affiliation(s)
- Heriberto Cuellar
- Department of Biology, Foster Hall, New Mexico State University, Las Cruces, NM 88003, USA
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6
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Coelho DJ, Sims DJ, Ruegg PJ, Minn I, Muench AR, Mitchell PJ. Cell type-specific and sexually dimorphic expression of transcription factor AP-2 in the adult mouse brain. Neuroscience 2005; 134:907-19. [PMID: 16009501 DOI: 10.1016/j.neuroscience.2005.04.060] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2004] [Revised: 04/20/2005] [Accepted: 04/27/2005] [Indexed: 11/19/2022]
Abstract
Expression of transcription factor AP-2 family genes in adult mouse brain regions was examined at RNA and protein levels and in tissue sections. AP-2 family RNA transcripts, nuclear AP-2 DNA binding activity, and AP-2 immunoreactivity were greatest in hindbrain and midbrain regions. Cells expressing AP-2 were predominantly differentiated neurons and were abundant in the solitary tract nucleus, hypoglossal nucleus, locus coeruleus, cerebellar molecular layer, superior colliculus, mitral cell layers of the main and accessory olfactory bulbs, and in some divisions of the bed nucleus of the stria terminalis. Sexually dimorphic expression of AP-2 was seen in the bed nucleus of the stria terminalis, a forebrain region required for regulation of gender-specific reproductive and social behaviors. In males, AP-2 expressing neurons were present in supracapsular, lateral ventral, and medial ventral divisions of the bed nucleus of the stria terminalis. In contrast, females had AP-2 expressing neurons in the lateral ventral division, but not the supracapsular division, and AP-2 expression in medial ventral division neurons oscillated during the estrus cycle. With the exception of the bed nucleus of the stria terminalis, forebrain regions generally lacked cells with high levels of AP-2. However, a small population of cells co-expressing low levels of AP-2 and Notch1 was sparsely distributed in the cerebral cortex and hippocampal dentate gyrus subgranular zone. Based on their variable levels of NeuN, a marker for differentiated neurons, these cells may include nascent neurons. A subset of cerebellar Purkinje cells also co-expressed low levels of AP-2 and Notch1. Together, the adult brain regions with AP-2 expressing neurons are notable for their importance in pathways that integrate sensory and neuroendocrine information for regulation of reproductive, social, and feeding behaviors. Our data suggest that AP-2 transcription factors contribute at multiple levels to adult brain function including regulation of gender-specific behavior.
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Affiliation(s)
- D J Coelho
- Department of Biochemistry and Molecular Biology, 201 Life Sciences Building, Pennsylvania State University, University Park, PA 16802, USA
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7
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Jiang JXS, Choi RCY, Siow NL, Lee HHC, Wan DCC, Tsim KWK. Muscle induces neuronal expression of acetylcholinesterase in neuron-muscle co-culture: transcriptional regulation mediated by cAMP-dependent signaling. J Biol Chem 2003; 278:45435-44. [PMID: 12963741 DOI: 10.1074/jbc.m306320200] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Presynaptic motor neuron synthesizes and secretes acetylcholinesterase (AChE) at vertebrate neuromuscular junctions. In order to determine the retrograde role of muscle in regulating the expression of AChE in motor neuron, a chimeric co-culture of NG108-15 cell, a cholinergic cell line that resembles motor neuron, with chick myotube was established to mimic the neuromuscular contact in vitro. A DNA construct of human AChE promoter tagged with luciferase (pAChE-Luc) was stably transfected into NG108-15 cells. The co-culture with myotubes robustly stimulated the promoter activity as well as the endogenous expression of AChE in pAChE-Luc stably transfected NG108-15 cells. Muscle extract derived from chick embryos when applied onto pAChE-Luc-expressing NG108-15 cells induced expressions of AChE promoter and endogenous AChE. The cAMP-responsive element mutation on human AChE promoter blocked the muscle-induced AChE transcriptional activity in cultured NG108-15 cells either in co-culturing with myotube or in applying muscle extract. The accumulation of intracellular cAMP and the phosphorylation of cAMP-responsive element-binding protein in cultured NG108-15 cells were stimulated by applied muscle extract. Part of the muscle-induced signaling was mimicked by application of calcitonin gene-related peptide in cultured NG108-15 cells. These results suggest the muscle-induced neuronal AChE expression in the co-culture is mediated by a cAMP-dependent signaling.
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Affiliation(s)
- Joy X S Jiang
- Department of Biology and Molecular Neuroscience Center, The Hong Kong University of Science and Technology, Clear Water Bay Road, Kowloon, Hong Kong, China
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8
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Clark JH, Haridasse V, Glazer RI. Modulation of the human protein kinase C alpha gene promoter by activator protein-2. Biochemistry 2002; 41:11847-56. [PMID: 12269829 DOI: 10.1021/bi025600k] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Protein kinase Calpha (PKCalpha) is a phospholipid-dependent protein-serine/threonine kinase that plays a major role in intracellular signaling pathways associated with transformation and tumor progression. Glioblastoma multiforme (GBM) and GBM cell lines exhibit increased levels of PKCalpha compared to normal brain tissue that relates to their proliferative and invasive potential. To investigate the transcriptional regulation of PKCalpha, the 5'-flanking sequence of the human PKCalpha gene was cloned and its promoter activity assessed in U-87 GBM cells. This sequence contained a TATA-less promoter region and a single transcription start site within an initiator sequence. Basal promoter activity was restricted to a region spanning -227 to +77 relative to the transcription start site. DNase I footprinting revealed multiple activator protein-2 (AP-2) binding sites and one Sp1 binding site within this region, and point mutations of two AP-2 elements resulted in a loss of DNA binding and transcriptional activation. Overexpression of Sp1 in either U-87 or insect cells increased transcription from the -227/+77 promoter region, whereas overexpression of AP-2 increased transcription only in insect cells. Cis activation of the promoter in U-87 cells was increased by phorbol esters but not by cyclic AMP or phosphatidylinositol 3-kinase inhibitors. These results provide evidence that cis activation of the basal promoter of the human PKCalpha gene occurs through an AP-2-dependent, phorbol ester-responsive pathway, which suggests an autoregulatory manner of transcription in GBM.
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Affiliation(s)
- Joannah Hackenbruck Clark
- Department of Pharmacology, Lombardi Cancer Center, Georgetown University School of Medicine, 3970 Reservoir Road NW, Washington, D.C. 20007, USA
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9
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Siow NL, Choi RCY, Cheng AWM, Jiang JXS, Wan DCC, Zhu SQ, Tsim KWK. A cyclic AMP-dependent pathway regulates the expression of acetylcholinesterase during myogenic differentiation of C2C12 cells. J Biol Chem 2002; 277:36129-36. [PMID: 12140295 DOI: 10.1074/jbc.m206498200] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The expression of acetylcholinesterase (AChE) is markedly increased during myogenic differentiation of C2C12 myoblasts to myotubes; the expression is mediated by intrinsic factor(s) during muscle differentiation. In order to analyze the molecular mechanisms regulating AChE expression during myogenic differentiation, a approximately 2.2-kb human AChE promoter tagged with a luciferase reporter gene, namely pAChE-Luc, was stably transfected into C2C12 cells. The profile of promoter-driven luciferase activity during myogenic differentiation of C2C12 myotubes was found to be similar to that of endogenous expression of AChE catalytic subunit. The increase of AChE expression was reciprocally regulated by a cAMP-dependent signaling pathway. The level of intracellular cAMP, the activity of cAMP-dependent protein kinase, the phosphorylation of cAMP-responsive element binding protein and the activity of cAMP- responsive element (CRE) were down-regulated during the myotube formation. Mutating the CRE site of human AChE promoter altered the original myogenic profile of the promoter activity and its suppressive response to cAMP. In addition, the suppressive effect of the CRE site is dependent on its location on the promoter. Therefore, our results suggest that a cAMP-dependent signaling pathway serves as a suppressive element in regulating the expression of AChE during early myogenesis.
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Affiliation(s)
- Nina L Siow
- Department of Biology and Molecular Neuroscience Center, The Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong, China
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10
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Choi RC, Siow NL, Zhu SQ, Wan DC, Wong YH, Tsim KW. The cyclic AMP-mediated expression of acetylcholinesterase in myotubes shows contrasting activation and repression between avian and mammalian enzymes. Mol Cell Neurosci 2001; 17:732-45. [PMID: 11312608 DOI: 10.1006/mcne.2001.0968] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Cyclic adenosine 3',5'-monophosphate (cAMP)-dependent signalling pathway has been proposed to regulate acetylcholinesterase (AChE) expression in chick muscle; however, its role in mammalian enzyme is not known. We provide several lines of evidence to suggest that the cAMP-mediated AChE expression in myotube is oppositely regulated between avian and mammalian enzymes. Human AChE promoter was tagged with luciferase, namely Hp-Luc, which was transfected into cultured chick myotubes. Application of cAMP and forskolin induced the expression of chick AChE but reduced human AChE promoter-driven luciferase activity. Transfection of cDNAs encoding active mutants of G proteins altered the intracellular cAMP level in myotubes as well as the expression of chick and human AChE. When the constitutively active forms of Activating Transcription Factor-1 (EWS/ATF-1 oncogene) were over expressed in Hp-Luc transfected myotubes, the expression of chick AChE transcript and protein increased from approximately 1.8- to approximately 2.5-fold, but the luciferase activity was decreased by over 60%. Overexpression of cAMP-responsive element binding protein (CREB) in Hp-Luc transfected myotubes markedly enhanced the cAMP-mediated AChE expression in up- and downregulated chick and human enzymes, respectively. In addition, CREB bound the CRE sequence of human AChE promoter. Mutation on the CRE site markedly enhanced the expression of the promoter-driven luciferase; however, its response to cAMP inhibition in cultured myotubes was still retained. These findings suggest that a cAMP-dependent pathway is contrasting activation and repression of AChE expression in chick and human muscles.
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Affiliation(s)
- R C Choi
- Department of Biology, Department of Biochemistry, Molecular Neuroscience Center, The Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong, China
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11
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Kim HS, Hong SJ, LeDoux MS, Kim KS. Regulation of the tyrosine hydroxylase and dopamine beta-hydroxylase genes by the transcription factor AP-2. J Neurochem 2001; 76:280-94. [PMID: 11146001 DOI: 10.1046/j.1471-4159.2001.00044.x] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The retinoic acid-inducible and developmentally regulated transcription factor AP-2 plays an important role during development. In adult mammals, AP-2 is expressed in both neural and non-neural tissues. However, the function of AP-2 in different neuronal phenotypes is poorly understood. In this study, transcriptional regulation of tyrosine hydroxylase (TH) and dopamine beta-hydroxylase (DBH) genes by AP-2 was investigated. AP-2 binding sites were identified in the upstream regions of both genes. Electrophoretic mobility shift assays (EMSA) and DNase I footprinting analyses indicate that the AP-2 interaction with these motifs is more prominent in catecholaminergic SK-N-BE(2)C and CATH.a than in non-catecholaminergic HeLa and HepG2 cell lines. Exogenous expression of AP-2 robustly transactivated TH and DBH promoter activities in non-catecholaminergic cell lines. While AP-2 regulates the DBH promoter activity via a single site, transactivation of the TH promoter by AP-2 appears to require multiple sites. In support of this, mutation of multiple AP-2 binding sites but not that of single site diminished the basal promoter activity of the TH gene in cell lines that express TH and abolished transactivation by exogenous AP-2 expression in cell lines that do not express TH. In contrast, mutation of a single AP-2 binding site of the DBH gene completely abolished transactivation by AP-2. Double-label immunohistochemistry showed that AP-2 is coexpressed with TH in noradrenergic and adrenergic neurons in both the central and peripheral nervous systems of adult rodents. Numerous non-catecholaminergic cell groups within the spinal cord, medulla, cerebellum, and pons also express AP-2. The concentration of AP-2 in dorsomedial locations along the neuraxis suggests a regionally specific role for this transcription factor in the regulation of neuronal function. Based on these findings we propose that AP-2 may coregulate TH and DBH gene expression and thus participate in expression/maintenance of neurotransmitter phenotypes in (nor)adrenergic neurons and neuroendocrine cells.
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Affiliation(s)
- H S Kim
- Department of Neurology, University of Tennessee, College of Medicine, Memphis, Tennessee, USA
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12
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Wan DC, Choi RC, Siow NL, Tsim KW. The promoter of human acetylcholinesterase is activated by a cyclic adenosine 3',5'-monophosphate-dependent pathway in cultured NG108-15 neuroblastoma cells. Neurosci Lett 2000; 288:81-5. [PMID: 10869820 DOI: 10.1016/s0304-3940(00)01200-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Different transcription elements have been proposed to play a role in the regulation of acetylcholinesterase (AChE) in muscle and neuron, and cyclic adenosine 3',5'-monophosphate (cAMP)-dependent pathway is one of them. In order to test the possible role of cAMP in regulating the expression of human AChE, an approximately 2.2 kb DNA fragment of human AChE promoter was linked up stream to a luciferase reporter. The chimeric DNA was transfected into cultured NG108-15 neuroblastoma cells. Application of Bt(2)-cAMP and forskolin increased the promoter driven luciferase activity over 2-fold in the transfected NG108-15 cells; the increase was parallel to the activation of endogenous AChE protein and enzymatic activity. The intracellular cAMP level was increased in the Galpha(sQL) (constitutively active mutant of Galpha(s)) cDNA transfected NG108-15 cells. The Galpha(sQL) cDNA transfected cells showed an increase of over 10-fold in the luciferase activity. In addition, a constitutively active mutant of activating transcription factor-1 (ATF-1) was able to turn on human AChE promoter by approximately 4-fold when they were co-expressed in the neuroblastoma cells. These results support the involvement of a cAMP-dependent pathway in regulating the expression of human AChE.
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Affiliation(s)
- D C Wan
- Department of Biochemistry, The Chinese University of Hong Kong, Shatin, China
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Culetto E, Combes D, Fedon Y, Roig A, Toutant JP, Arpagaus M. Structure and promoter activity of the 5' flanking region of ace-1, the gene encoding acetylcholinesterase of class A in Caenorhabditis elegans. J Mol Biol 1999; 290:951-66. [PMID: 10438595 DOI: 10.1006/jmbi.1999.2937] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We report the structure and the functional activity of the promoter region of ace-1, the gene encoding acetylcholinesterase of class A in the nematode Caenorhabditis elegans. We found that ace-1 was trans -spliced to the SL1 spliced leader and that transcription was initiated at a cluster of multiple starts. There was neither a TATA nor a CAAT box at consensus distances from these starts. Interspecies sequence comparison of the 5' regions of ace-1 in C. elegans and in the related nematode Caenorhabditis briggsae identified four blocks of conserved sequences located within a sequence of 2.4 kilobases upstream from the initiator ATG. In vitro expression of CAT reporter genes in mammalian cells allowed the determination of a minimal promoter in the first 288 nucleotides. In phenotype rescue experiments in vivo, the ace-1 gene containing 2.4 kilobases of 5' flanking region of either C. elegans or C. briggsae was found to restore a coordinated mobility to the uncoordinated double mutants ace-1(-);ace-2(-)of C. elegans. This showed that the ace-1 promoter was contained in 2.4 kilobases of the 5' region, and indicated that cis -regulatory elements as well as coding sequences of ace-1 were functionally conserved between the two nematode species. The pattern of ace-1 expression was established through microinjection of Green Fluorescent Protein reporter gene constructs and showed a major mesodermal expression. Deletion analysis showed that two of the four blocks of conserved sequences act as tissue-specific activators. The distal block is a mesodermal enhancer responsible for the expression in body wall muscle cells, anal sphincter and vulval muscle cells. Another block of conserved sequence directs expression in pharyngeal muscle cells pm5 and three pairs of cephalic sensory neurons.
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Affiliation(s)
- E Culetto
- Différenciation Cellulaire et Croissance, INRA, 2 place Viala, Montpellier, 34060, France
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Atanasova E, Chiappa S, Wieben E, Brimijoin S. Novel messenger RNA and alternative promoter for murine acetylcholinesterase. J Biol Chem 1999; 274:21078-84. [PMID: 10409660 DOI: 10.1074/jbc.274.30.21078] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A portion of the 5'-flanking region of murine acetylcholinesterase was cloned from genomic DNA by 5'-rapid amplification of genomic ends, identified in a mouse genomic library, and sequenced. Multiple potential binding sites for universal and tissue-specific transcription factors were suggestive of a promoter region within this DNA sequence. Potential promoter activity was confirmed by coupling the new sequence to the open reading frame of a luciferase reporter gene in transient expression experiments with nerve and muscle cells. 5'-Rapid amplification of cDNA ends with templates from multiple sources revealed a novel transcription start site (at position -626, relative to translation start), located 32 bases downstream from a TATAA sequence. This start site appeared to mark a novel exon (1a) comprising 291 base pairs between positions -335 and -626, relative to the translation start. Supporting this conclusion, polymerase chain reactions with cDNA from mouse brain, heart, and other tissues, consistently amplified a transcript containing the exon 1a sequence fused to the invariant sequence beginning at position -22 in exon 2, but lacking exon 1. Northern blot analyses confirmed the in vivo expression of exon 1a-containing transcripts, especially in heart, brain, liver, and kidney. These results indicate that the murine acetylcholinesterase gene has a functioning alternative promoter that may influence expression of acetylcholinesterase in certain tissues.
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Affiliation(s)
- E Atanasova
- Department of Pharmacology, Mayo Clinic, Rochester, Minnesota 55905, USA
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15
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Chan RY, Boudreau-Larivière C, Angus LM, Mankal FA, Jasmin BJ. An intronic enhancer containing an N-box motif is required for synapse- and tissue-specific expression of the acetylcholinesterase gene in skeletal muscle fibers. Proc Natl Acad Sci U S A 1999; 96:4627-32. [PMID: 10200313 PMCID: PMC16383 DOI: 10.1073/pnas.96.8.4627] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
mRNAs encoding acetylcholinesterase (AChE; EC 3.1.1.7) are highly concentrated within the postsynaptic sarcoplasm of adult skeletal muscle fibers, where their expression is markedly influenced by nerve-evoked electrical activity and trophic factors. To determine whether transcriptional regulatory mechanisms account for the synaptic accumulation of AChE transcripts at the mammalian neuromuscular synapse, we cloned a 5.3-kb DNA fragment that contained the 5' regulatory region of the rat AChE gene and generated several constructs in which AChE promoter fragments were placed upstream of the reporter gene lacZ and a nuclear localization signal (nls). Using a recently described transient expression assay system in intact skeletal muscle, we show that this AChE promoter fragment directs the synapse-specific expression of the reporter gene. Deletion analysis revealed that a 499-bp fragment located in the first intron of the AChE gene is essential for expression in muscle fibers. Further analysis showed that sequences contained within this intronic fragment were (i) functionally independent of position and orientation and (ii) inactive in hematopoietic cells. Disruption of an N-box motif located within this DNA fragment reduced by more than 80% the expression of the reporter gene in muscle fibers. In contrast, mutation of an adjacent CArG element had no effect on nlsLacZ expression. Taken together, these results indicate that a muscle-specific enhancer is present within the first intron of the AChE gene and that an intronic N-box is essential for the regulation of AChE along skeletal muscle fibers.
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MESH Headings
- Acetylcholinesterase/biosynthesis
- Acetylcholinesterase/genetics
- Animals
- Base Sequence
- Enhancer Elements, Genetic
- Gene Expression Regulation, Enzymologic
- Genes, Reporter
- Genomic Library
- Humans
- Introns
- Kidney/enzymology
- Leukemia, Erythroblastic, Acute
- Mice
- Molecular Sequence Data
- Muscle Fibers, Skeletal/enzymology
- Muscle, Skeletal/enzymology
- Organ Specificity
- Promoter Regions, Genetic
- Rats
- Recombinant Fusion Proteins/biosynthesis
- Regulatory Sequences, Nucleic Acid
- Sequence Alignment
- Sequence Homology, Nucleic Acid
- Synapses/metabolism
- Transfection
- Tumor Cells, Cultured
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Affiliation(s)
- R Y Chan
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, 451 Smyth Road, Ottawa, ON K1H 8M5, Canada
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16
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Lukiw WJ, Pelaez RP, Martinez J, Bazan NG. Budesonide epimer R or dexamethasone selectively inhibit platelet-activating factor-induced or interleukin 1beta-induced DNA binding activity of cis-acting transcription factors and cyclooxygenase-2 gene expression in human epidermal keratinocytes. Proc Natl Acad Sci U S A 1998; 95:3914-9. [PMID: 9520467 PMCID: PMC19937 DOI: 10.1073/pnas.95.7.3914] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
To further understand the molecular mechanism of glucocorticoid action on gene expression, DNA-binding activities of the cis-acting transcription factors activator protein 1 (AP1), AP2, Egr1 (zif268), NF-kappaB, the signal transducers and activators of transcription proteins gamma interferon activation site (GAS), Sis-inducible element, and the TATA binding protein transcription factor II D (TFIID) were examined in human epidermal keratinocytes. The cytokine interleukin 1beta (IL-1beta) and platelet-activating factor (PAF), both potent mediators of inflammation, were used as triggers for gene expression. Budesonide epimer R (BUDeR) and dexamethasone (DEX) were studied as potential antagonists. BUDeR or DEX before IL-1beta- or PAF-mediated gene induction elicited strong inhibition of AP1-, GAS-, and in particular NF-kappaB-DNA binding (P < 0.001, ANOVA). Only small effects were noted on AP2, Egr1 (zif268), and Sis-inducible element-DNA binding (P > 0.05). No significant effect was noted on the basal transcription factor TFIID recognition of TATA-containing core promoter sequences (P > 0.68). To test the hypothesis that changing cis-acting transcription factor binding activity may be involved in inflammatory-response related gene transcription, RNA message abundance for human cyclooxygenase (COX)-1 and -2 (E.C.1.14.99.1) was assessed in parallel by using reverse transcription-PCR. Although the COX-1 gene was found to be expressed at constitutively low levels, the TATA-containing COX-2 gene, which contains AP1-like, GAS, and NF-kappaB DNA-binding sites in its immediate promoter, was found to be strongly induced by IL-1beta or PAF (P < 0.001). BUDeR and DEX both suppressed COX-2 RNA message generation; however, no correlation was associated with TFIID-DNA binding. These results suggest that on stimulation by mediators of inflammation, although the basal transcription machinery remains intact, modulation of cis-activating transcription factor AP1, GAS, and NF-kappaB-DNA binding by the glucocorticoids BUDeR and DEX play important regulatory roles in the extent of specific promoter activation and hence the expression of key genes involved in the inflammatory response.
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Affiliation(s)
- W J Lukiw
- Louisiana State University Medical Center, School of Medicine, Neuroscience Center of Excellence and Department of Ophthalmology, 2020 Gravier Street, Suite D, New Orleans, LA 70112-2272, USA
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17
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Abstract
Apolipoprotein E (apoE), one of the major plasma lipoproteins, also is expressed in a variety of cell types, including the glial cells of the nervous system. apoE is involved in processes of degeneration and regeneration after nerve lesions as well as in the pathogenesis of Alzheimer's disease (AD). Glial synthesis of apoE is activated in response to injury both in the peripheral and central nervous system. We now report that the activity of the proximal apoE promoter in astrocytes is upregulated by cAMP and retinoic acid, which act synergistically. Sequence analysis of the apoE promoter indicated the presence of several AP-2 consensus sequences that could mediate the stimulatory effect of cAMP and retinoic acid. The possible functional role of AP-2 was examined by cotransfection of AP-2-deficient HepG2 cells with an apoE promoter construct and a human AP-2 expression construct. Cotransfection with AP-2 significantly elevated apoE promoter activity. DNase I footprinting technique revealed the existence of two binding sites for recombinant AP-2 in regions from -48 to -74 and from -107 to -135 of the apoE promoter. Mutations in these regions markedly impaired the trans-stimulatory effect of AP-2. These results indicate the existence of functional AP-2 sites in the promoter region of apoE that could contribute to the complex regulation of this gene in developmental, degenerative, and regenerative processess of the nervous system.
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18
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Friedman A, Kaufer D, Shemer J, Hendler I, Soreq H, Tur-Kaspa I. Pyridostigmine brain penetration under stress enhances neuronal excitability and induces early immediate transcriptional response. Nat Med 1996; 2:1382-5. [PMID: 8946841 DOI: 10.1038/nm1296-1382] [Citation(s) in RCA: 262] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Pyridostigmine, a carbamate acetylcholinesterase (AChE) inhibitor, is routinely employed in the treatment of the autoimmune disease myasthenia gravis. Pyridostigmine is also recommended by most Western armies for use as pretreatment under threat of chemical warfare, because of its protective effect against organophosphate poisoning. Because of this drug's quaternary ammonium group, which prevents its penetration through the blood-brain barrier, the symptoms associated with its routine use primarily reflect perturbations in peripheral nervous system functions. Unexpectedly, under a similar regimen, pyridostigmine administration during the Persian Gulf War resulted in a greater than threefold increase in the frequency of reported central nervous system symptoms. This increase was not due to enhanced absorption (or decreased elimination) of the drug, because the inhibition efficacy of serum butyryl-cholinesterase was not modified. Because previous animal studies have shown stress-induced disruption of the blood-brain barrier, an alternative possibility was that the stress situation associated with war allowed pyridostigmine penetration into the brain. Here we report that after mice were subjected to a forced swim protocol (shown previously to simulate stress), an increase in blood-brain barrier permeability reduced the pyridostigmine dose required to inhibit mouse brain AChE activity by 50% to less than 1/100th of the usual dose. Under these conditions, peripherally administered pyridostigmine increased the brain levels of c-fos oncogene and AChE mRNAs. Moreover, in vitro exposure to pyridostigmine increased both electrical excitability and c-fos mRNA levels in brain slices, demonstrating that the observed changes could be directly induced by pyridostigmine. These findings suggest that peripherally acting drugs administered under stress may reach the brain and affect centrally controlled functions.
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Affiliation(s)
- A Friedman
- Department of Biological Chemistry, Life Sciences Institute, Hebrew University, Jerusalem, Israel
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19
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Dupree JL, Bigbee JW. Acetylcholinesterase inhibitor treatment delays recovery from axotomy in cultured dorsal root ganglion neurons. JOURNAL OF NEUROCYTOLOGY 1996; 25:439-54. [PMID: 8899566 DOI: 10.1007/bf02284814] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We have previously reported that dorsal root ganglion neurons cultured in the presence of the highly specific, reversible acetylcholinesterase inhibitor 1,5-bis-(4-allyldimethylammoniumphenyl) pentan-3-one dibromide (BW284c51), showed significantly reduced neurite outgrowth and contained massive perikaryal inclusions of neurofilaments. In the present report we have more closely examined these changes in a time course study over a 21-day culture period using a combined morphological, immunocytochemical and enzymatic approach and additionally, describe, the effects of acetylcholinesterase inhibitor treatment on the state of neurofilament phosphorylation. Finally, we have examined the effects of co-administration of N6,2'-0-dibutyryladenosine 3':5'-cyclic monophosphate (dbcAMP) with BW284c51. At 1 day in culture, both control and treated cells displayed eccentrically located nuclei, numerous polysomes and perikaryal accumulations of neurofilaments which were immunoreactive with both phosphorylation- and nonphosphorylation-dependent neurofilament antibodies. These cytological changes, which are common features of the chromatolytic reaction following axotomy in vivo, rapidly resolved in the control neurons, where by 7 days in culture, the neurofilament accumulations had completely disappeared and neurite outgrowth was robust. In contrast, inhibitor-treated neurons retained the post-axotomy features up to 21 days and had significantly reduced neurite outgrowth. In addition, we have investigated a possible role of cyclic adenosine monophosphate (cAMP) in the recovery process since it has been shown to enhance neuritic outgrowth in cultured neurons. Our results demonstrate that the addition of dbcAMP, a membrane permeable analog of cAMP, significantly enhanced neuritic outgrowth and accelerated the recovery of BW284c51-treated dorsal root ganglion cells, as gauged by the disappearance of the axotomy-related cytological changes. Treatment with dbcAMP also increased acetylcholinesterase activity which has been positively correlated with neurite outgrowth both in vivo and in vitro. Together, these observations suggest that acetylcholinesterase has a non-cholinolytic, neurotrophic role in neuronal regeneration and development.
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MESH Headings
- Acetylcholinesterase/metabolism
- Animals
- Axons/physiology
- Benzenaminium, 4,4'-(3-oxo-1,5-pentanediyl)bis(N,N-dimethyl-N-2-propenyl-), Dibromide/pharmacology
- Bucladesine
- Cell Nucleus/drug effects
- Cell Nucleus/physiology
- Cell Nucleus/ultrastructure
- Cells, Cultured
- Cholinesterase Inhibitors/pharmacology
- Embryo, Mammalian
- Fluorescent Antibody Technique
- Ganglia, Spinal/cytology
- Ganglia, Spinal/physiology
- Immunohistochemistry
- Kinetics
- Microscopy, Electron
- Neurites/drug effects
- Neurites/physiology
- Neurites/ultrastructure
- Neurofilament Proteins/analysis
- Neurofilament Proteins/metabolism
- Neurons/drug effects
- Neurons/physiology
- Neurons/ultrastructure
- Rats
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Affiliation(s)
- J L Dupree
- Department of Anatomy, Virginia Commonwealth University, Richmond 23298-0709, USA
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20
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Getman DK, Mutero A, Inoue K, Taylor P. Transcription factor repression and activation of the human acetylcholinesterase gene. J Biol Chem 1995; 270:23511-9. [PMID: 7559515 DOI: 10.1074/jbc.270.40.23511] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Acetylcholinesterase in man is encoded by a single gene, ACHE, located on chromosome 7q22. In this study, the transcription start sites and major DNA promoter elements controlling the expression of this gene have been characterized by structural and functional studies. Immediately upstream of the first untranslated exon of the gene are GC-rich sequences containing consensus binding sites for several transcription factors, including Sp1, EGR-1 and AP2. In vitro transcription studies and RNase protection analyses of mRNA isolated from human NT2/D1 teratocarcinoma cells reveal that two closely spaced transcription cap sites are located at a consensus initiator (Inr) element similar to that found in the terminal transferase gene. Transient transfection of mutant genes shows that removal of three bases of this initiator sequence reduces promoter activity by 98% in NT2/D1 cells. In vitro transcription studies and transient transfection of a series of 5' deletion mutants of the ACHE promoter linked to a luciferase reporter show an Sp1 site at -71 to be essential for promoter activity. Purified Sp1 protein protects this site from DNase cleavage during in vitro footprinting experiments. A conserved AP2 consensus binding site, located between the GC box elements and the Inr, is protected by recombinant AP2 protein in DNase footprinting experiments, induces a mobility shift with AP2 protein and AP2-containing cell extracts, and fosters inhibition of transcription by AP2 as measured by transient transfection in mouse and human cell lines and in in vitro transcription reactions. These results indicate that AP2 functions as a repressor of human ACHE and mouse Ache transcription.
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Affiliation(s)
- D K Getman
- Department of Pharmacology, University of California, San Diego, La Jolla 92093-0636, USA
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21
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Jbilo O, Bartels CF, Chatonnet A, Toutant JP, Lockridge O. Tissue distribution of human acetylcholinesterase and butyrylcholinesterase messenger RNA. Toxicon 1994; 32:1445-57. [PMID: 7886701 DOI: 10.1016/0041-0101(94)90416-2] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Cholinesterase inhibitors occur naturally in the calabar bean (eserine), green potatoes (solanine), insect-resistant crab apples, the coca plant (cocaine) and snake venom (fasciculin). There are also synthetic cholinesterase inhibitors, for example man-made insecticides. These inhibitors inactivate acetylcholinesterase and butyrylcholinesterase as well as other targets. From a study of the tissue distribution of acetylcholinesterase and butyrylcholinesterase mRNA by Northern blot analysis, we have found the highest levels of butyrylcholinesterase mRNA in the liver and lungs, tissues known as the principal detoxication sites of the human body. These results indicate that butyrylcholinesterase may be a first line of defense against poisons that are eaten or inhaled.
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Affiliation(s)
- O Jbilo
- Institut National de la Recherche Agronomique, Montpellier, France
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22
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Jbilo O, L'Hermite Y, Talesa V, Toutant JP, Chatonnet A. Acetylcholinesterase and butyrylcholinesterase expression in adult rabbit tissues and during development. EUROPEAN JOURNAL OF BIOCHEMISTRY 1994; 225:115-24. [PMID: 7925428 DOI: 10.1111/j.1432-1033.1994.00115.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A large cDNA fragment covering the complete sequence of the mature catalytic subunit of rabbit acetylcholinesterase (AChE) has been cloned and sequenced. This sequence was compared to that of rabbit butyrylcholinesterase [BChE; Jbilo, O. & Chatonnet, A. (1990) Nucleic Acids Res. 18, 3990]. Amino acid sequences of AChE and BChE have 51% identity. They both possessed a choline-binding site W84, a catalytic triad S200-H440-E327 and six cysteine residues (positions 67-94, 254-265, 402-521) in conserved sequence positions to those that form three intrachain disulfide bonds in all cholinesterases (by convention, numbering of amino acids is that used for Torpedo AChE). Rabbit AChE had a larger number of aromatic residues lining the active-site gorge than rabbit BChE (14 compared to 8, respectively) and a smaller number of potential N-glycosylation sites (3 compared to 8, respectively). Both catalytic subunits have a hydrophilic C-terminus (catalytic subunits of type T). Expression of acetylcholinesterase and butyrylcholinesterase genes (ACHE and BCHE) was studied in rabbit tissues and during development by a correlation of Northern-blot analysis and enzymic activities. This correlation was rendered difficult by the presence of an eserine-resistant esterase active on butyrylthiocholine in serum, liver and lung. When the contribution of this carboxylesterase was taken into account, brain was found as the richest source of BChE followed by lung and heart. Rabbit liver had a very low content of BChE that correlated with the low BChE activity in plasma. During development, BCHE transcripts were detected as early as day 10 post coitum, whereas ACHE transcripts appeared only on day 12.
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Affiliation(s)
- O Jbilo
- Laboratorire de Différenciation cellulaire et Croissance, INRA, Montpellier, France
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23
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Jbilo O, Toutant J, Vatsis K, Chatonnet A, Lockridge O. Promoter and transcription start site of human and rabbit butyrylcholinesterase genes. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)31897-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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24
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Layer PG, Willbold E. Cholinesterases in avian neurogenesis. INTERNATIONAL REVIEW OF CYTOLOGY 1994; 151:139-81. [PMID: 8014021 DOI: 10.1016/s0074-7696(08)62632-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- P G Layer
- Technical University of Darmstadt, Institute for Zoology, Germany
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25
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Massoulié J, Pezzementi L, Bon S, Krejci E, Vallette FM. Molecular and cellular biology of cholinesterases. Prog Neurobiol 1993; 41:31-91. [PMID: 8321908 DOI: 10.1016/0301-0082(93)90040-y] [Citation(s) in RCA: 836] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- J Massoulié
- Laboratoire de Neurobiologie, CNRS URA 295, Ecole Normale Supérieure, Paris, France
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