Abstract
A leucine-rich nuclear export signal (NES) allows rapid export of proteins from cell nuclei. Microinjection studies revealed a role for the guanosine triphosphatase (GTPase) Ran in NES-mediated export. Nuclear injection of a Ran mutant (Thr24 --> Asn) blocked protein export but not import, whereas depletion of the Ran nucleotide exchange factor RCC1 blocked protein import but not export. However, injection of Ran GTPase-activating protein (RanGAP) into RCC1-depleted cell nuclei inhibited export. Coinjection with Ran mutants insensitive to RanGAP prevented this inhibition. Therefore, NES-mediated protein export appears to require a Ran-GTP complex but does not require Ran-dependent GTP hydrolysis.
Publication types
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Animals
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Biological Transport
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Carrier Proteins / metabolism
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Cell Cycle Proteins*
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Cell Line
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Cell Nucleus / metabolism*
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Cricetinae
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Cytoplasm
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DNA-Binding Proteins / metabolism
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GTP Phosphohydrolases / metabolism*
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GTP-Binding Proteins / metabolism
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GTPase-Activating Proteins*
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Glutathione Transferase / metabolism
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Green Fluorescent Proteins
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Guanine Nucleotide Exchange Factors*
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Guanosine Triphosphate / metabolism*
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Luminescent Proteins / metabolism
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Mutation
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Nuclear Envelope / metabolism
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Nuclear Localization Signals
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Nuclear Proteins / genetics
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Nuclear Proteins / metabolism*
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Receptors, Glucocorticoid / metabolism
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Recombinant Fusion Proteins / metabolism
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Temperature
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ran GTP-Binding Protein
Substances
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Carrier Proteins
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Cell Cycle Proteins
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DNA-Binding Proteins
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GTPase-Activating Proteins
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Guanine Nucleotide Exchange Factors
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Luminescent Proteins
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Nuclear Localization Signals
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Nuclear Proteins
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Receptors, Glucocorticoid
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Recombinant Fusion Proteins
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ran-binding protein 1
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Green Fluorescent Proteins
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Guanosine Triphosphate
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Glutathione Transferase
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GTP Phosphohydrolases
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GTP-Binding Proteins
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ran GTP-Binding Protein