Abstract
The mechanisms regulating nuclear export of proteins are not fully understood. To investigate whether the efficiency of protein nuclear export may depend on ongoing RNA synthesis and/or mRNA nuclear export, we used a microinjection approach with a fluorescent reporter protein containing a nuclear export signal (NES) and scored protein export in human fibroblasts under conditions when the synthesis or export of mRNAs was inhibited. We show that inhibition of transcription significantly attenuated generic NES-dependent nuclear export. Furthermore, digestion of endogenous nuclear RNAs by co-microinjection of RNAse A inhibited NES-dependent nuclear export. Finally, nuclear export of the NES reporter protein was significantly inhibited in cells in which nuclear export of mRNAs had been specifically blocked by microinjection of anti-TAP antibodies or by expression of a dominant negative form of NUP160. These results demonstrate a novel role for ongoing synthesis and export of mRNAs in NES-dependent protein nuclear export.
Publication types
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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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ATP-Binding Cassette Transporters
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Active Transport, Cell Nucleus / drug effects*
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Cell Nucleus / drug effects
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Cell Nucleus / metabolism*
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Cells, Cultured
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Cytoplasm / drug effects
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Cytoplasm / metabolism
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Dose-Response Relationship, Drug
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Exportin 1 Protein
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Fibroblasts / cytology
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Fibroblasts / metabolism
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Fluorescent Dyes
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Glutathione Transferase / metabolism
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Green Fluorescent Proteins
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Histocompatibility Antigens Class I / metabolism
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Humans
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Karyopherins / metabolism
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Luminescent Proteins
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Microinjections
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Models, Biological
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Nuclear Localization Signals / metabolism*
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Nuclear Pore Complex Proteins / metabolism
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Nuclear Proteins / metabolism
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RNA, Messenger / antagonists & inhibitors
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RNA, Messenger / biosynthesis*
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RNA, Messenger / drug effects
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RNA, Messenger / metabolism*
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Receptors, Cytoplasmic and Nuclear*
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Recombinant Proteins / metabolism
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Rhodamines
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Ribonuclease, Pancreatic / pharmacology
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Transcription, Genetic / drug effects
Substances
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ATP-Binding Cassette Transporters
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Fluorescent Dyes
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Histocompatibility Antigens Class I
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Karyopherins
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Luminescent Proteins
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NUP160 protein, human
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Nuclear Localization Signals
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Nuclear Pore Complex Proteins
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Nuclear Proteins
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RNA, Messenger
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Receptors, Cytoplasmic and Nuclear
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Recombinant Proteins
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Rhodamines
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transporter associated with antigen processing (TAP)
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Green Fluorescent Proteins
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Glutathione Transferase
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Ribonuclease, Pancreatic