Abstract
We show that neurotransmitter release at Caenorhabditis elegans neuromuscular junctions is facilitated by a presynaptic pathway composed of a Gqalpha (EGL-30), EGL-8 phospholipase Cbeta (PLCbeta), and the diacylglycerol- (DAG-) binding protein UNC-13. Activation of this pathway increased release of acetylcholine at neuromuscular junctions, whereas inactivation decreased release. Phorbol esters stimulated acetylcholine release, and this effect was blocked by a mutation that eliminates phorbol ester binding to UNC-13. Expression of a constitutively membrane-bound form of UNC-13 restored acetylcholine release to mutants lacking the egl-8 PLCbeta. Activation of this pathway with muscarinic agonists caused UNC-13 to accumulate in punctate structures in the ventral nerve cord. These results suggest that presynaptic DAG facilitates synaptic transmission and that part of this effect is mediated by UNC-13.
Publication types
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Comment
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Acetylcholine / metabolism
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Amino Acid Sequence / genetics
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Animals
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Caenorhabditis elegans
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Caenorhabditis elegans Proteins*
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Carrier Proteins
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Diglycerides / metabolism
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GTP-Binding Proteins / physiology*
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Helminth Proteins / metabolism
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Isoenzymes / physiology*
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Molecular Sequence Data
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Motor Neurons / physiology
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Muscarinic Agonists / pharmacology
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Neuromuscular Junction / metabolism
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Phospholipase C beta
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Synaptic Transmission / physiology*
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Tetradecanoylphorbol Acetate / pharmacology
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Tissue Distribution / physiology
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Type C Phospholipases / physiology*
Substances
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Caenorhabditis elegans Proteins
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Carrier Proteins
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Diglycerides
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Helminth Proteins
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Isoenzymes
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Muscarinic Agonists
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phorbol ester binding protein
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Type C Phospholipases
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Phospholipase C beta
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GTP-Binding Proteins
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Acetylcholine
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Tetradecanoylphorbol Acetate