Abstract
Rab3A small GTP-binding protein and its associated proteins, such as Rabphilin-3A, a putative target protein for Rab3A, MSS4, a stimulatory GDP/GTP exchange protein for Rab3A, and Rab GDI, a translocator for the Rab family members including Rab3A, are implicated in neurotransmitter release. We have investigated here the phosphorylation of these proteins by cyclic AMP-dependent protein kinase (protein kinase A). Neither Rab3A, MSS4, nor Rab GDI was phosphorylated, but Rabphilin-3A was phosphorylated Rab GDI was phosphorylated, but Rabphilin-3A was phosphorylated at its N-terminal region. About 0.8 mol of phosphate was maximally incorporated into one mol of Rabphilin-3A. These results suggest that Rabphilin-3A is one of the targets for protein kinase A which modulates neurotransmitter release.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Adaptor Proteins, Signal Transducing
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Animals
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Cell Line
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Cell Membrane / metabolism
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Cyclic AMP-Dependent Protein Kinases / metabolism*
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GTP-Binding Proteins / isolation & purification
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GTP-Binding Proteins / metabolism*
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Kinetics
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Nerve Tissue Proteins / isolation & purification
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Nerve Tissue Proteins / metabolism*
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Oligopeptides / metabolism
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Phosphorylation
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Rabphilin-3A
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Recombinant Proteins / isolation & purification
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Recombinant Proteins / metabolism
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Spodoptera
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Substrate Specificity
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Transfection
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Vesicular Transport Proteins
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rab GTP-Binding Proteins*
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rab3 GTP-Binding Proteins
Substances
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Adaptor Proteins, Signal Transducing
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Nerve Tissue Proteins
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Oligopeptides
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Recombinant Proteins
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Vesicular Transport Proteins
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kemptide
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Cyclic AMP-Dependent Protein Kinases
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GTP-Binding Proteins
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rab GTP-Binding Proteins
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rab3 GTP-Binding Proteins