Abstract
Translocation of signaling molecules, MAPK in particular, from the cytosol to nucleus represents a universal key element in initiating the gene program that determines memory consolidation. Translocation mechanisms and their behavioral impact, however, remain to be determined. Here, we report that a highly conserved nuclear transporter, Drosophila importin-7 (DIM-7), regulates import of training-activated MAPK for consolidation of long-term memory (LTM). We show that silencing DIM-7 functions results in impaired LTM, whereas overexpression of DIM-7 enhances LTM. This DIM-7-dependent regulation of LTM is confined to a consolidation time window and in mushroom body neurons. Image data show that bidirectional alteration in DIM-7 expression results in proportional changes in the intensity of training-activated MAPK accumulated within the nuclei of mushroom body neurons during LTM consolidation. Such DIM-7-regulated nuclear accumulation of activated MAPK is observed only in the training specified for LTM induction and determines the amplitude, but not the time course, of memory consolidation.
Keywords:
Drosophila; MAPK; consolidation; importin; long-term memory.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Active Transport, Cell Nucleus / physiology
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Animals
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Avoidance Learning / drug effects
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Avoidance Learning / physiology*
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Butadienes / pharmacology
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Cell Nucleus / metabolism*
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Cycloheximide / pharmacology
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Drosophila Proteins / biosynthesis
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Drosophila Proteins / deficiency
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Drosophila Proteins / genetics
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Drosophila Proteins / physiology*
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Drosophila melanogaster / drug effects
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Drosophila melanogaster / physiology*
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Enzyme Activation
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Gene Expression Regulation / drug effects
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Genes, Reporter
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Hot Temperature
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Karyopherins / biosynthesis
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Karyopherins / deficiency
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Karyopherins / genetics
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Karyopherins / physiology*
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MAP Kinase Signaling System*
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Memory Consolidation / drug effects
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Memory Consolidation / physiology*
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Memory, Long-Term / drug effects
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Memory, Long-Term / physiology*
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Memory, Short-Term / physiology
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Mifepristone / pharmacology
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Mitogen-Activated Protein Kinases / metabolism
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Mushroom Bodies / cytology
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Mushroom Bodies / physiology*
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Neurons / drug effects
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Neurons / metabolism
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Nitriles / pharmacology
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Recombinant Fusion Proteins / metabolism
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Smell / physiology
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Time Factors
Substances
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Butadienes
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Drosophila Proteins
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Karyopherins
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Msk protein, Drosophila
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Nitriles
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Recombinant Fusion Proteins
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U 0126
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Mifepristone
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Cycloheximide
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Mitogen-Activated Protein Kinases