title: ATP acts via P2Y1 receptors to stimulate acetylcholinesterase and acetylcholine receptor expression: transduction and transcription control.
abstract: At the vertebrate neuromuscular junction ATP is known to stabilize acetylcholine in the synaptic vesicles and to be co-released with it. We have shown previously that a nucleotide receptor, the P2Y1 receptor, is localized at the junction, and we propose that this mediates a trophic role for synaptic ATP there. Evidence in support of this and on its mechanism is given here. With the use of chick or mouse myotubes expressing promoter-reporter constructs from genes of acetylcholinesterase (AChE) or of the acetylcholine receptor subunits, P2Y1 receptor agonists were shown to stimulate the transcription of each of those genes. The pathway to activation of the AChE gene was shown to involve protein kinase C and intracellular Ca 2+ release. Application of dominant-negative or constitutively active mutants, or inhibitors of specific kinases, showed that it further proceeds via some of the known intermediates of extracellular signal-regulated kinase phosphorylation. In both chick and mouse myotubes this culminates in activation of the transcription factor Elk-1, confirmed by gel mobility shift assays and by the nuclear accumulation of phosphorylated Elk-1. All of the aforementioned activations by agonist were amplified when the content of P2Y1 receptors was boosted by transfection, and the activations were blocked by a P2Y1-selective antagonist. Two Elk-1 binding site sequences present in the AChE gene promoter were jointly sufficient to drive ATP-induced reporter gene transcription. Thus ATP regulates postsynaptic gene expression via a pathway to a selective transcription factor activation.
authors.affiliation: Department of Biology and Molecular Neuroscience Center, Hong Kong University of Science and Technology, Hong Kong, China.
authors.forename: Roy C Y
authors.initials: RC
authors.lastname: Choi
authors.forename: Nina L
authors.initials: NL
authors.lastname: Siow
authors.forename: Anthony W M
authors.initials: AW
authors.lastname: Cheng
authors.forename: Karen K Y
authors.initials: KK
authors.lastname: Ling
authors.forename: Edmund K K
authors.initials: EK
authors.lastname: Tung
authors.forename: Joseph
authors.initials: J
authors.lastname: Simon
authors.forename: Eric A
authors.initials: EA
authors.lastname: Barnard
authors.forename: Karl W K
authors.initials: KW
authors.lastname: Tsim
mesh_terms: D000110:Acetylcholinesterase / Q000235:genetics / Q000378:metabolism*; D000244:Adenosine Diphosphate / Q000031:analogs & derivatives* / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000494:pharmacology / Q000502:physiology*; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002478:Cells, Cultured; D002642:Chick Embryo; D003600:Cytosol / Q000378:metabolism; D004268:DNA-Binding Proteins; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology*; D017930:Genes, Reporter; D051379:Mice; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D018485:Muscle Fibers, Skeletal / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D032446:Myoblasts / Q000166:cytology / Q000378:metabolism; D009469:Neuromuscular Junction / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D011401:Promoter Regions, Genetic / Q000502:physiology; D011493:Protein Kinase C / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D011950:Receptors, Cholinergic / Q000096:biosynthesis* / Q000235:genetics; D018048:Receptors, Purinergic P2 / Q000235:genetics / Q000378:metabolism*; D058472:Receptors, Purinergic P2Y1; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D013873:Thionucleotides / Q000494:pharmacology; D014157:Transcription Factors; D014158:Transcription, Genetic / Q000502:physiology; D014161:Transduction, Genetic; D050807:ets-Domain Protein Elk-1
chemical_list: D004268:DNA-Binding Proteins; C494113:Elk1 protein, mouse; C546383:P2ry1 protein, mouse; D011518:Proto-Oncogene Proteins; D011950:Receptors, Cholinergic; D018048:Receptors, Purinergic P2; D058472:Receptors, Purinergic P2Y1; D013873:Thionucleotides; D014157:Transcription Factors; D050807:ets-Domain Protein Elk-1; C002480:methylthio-ADP; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D011493:Protein Kinase C; D020928:Mitogen-Activated Protein Kinases; D000110:Acetylcholinesterase; D002118:Calcium