Abstract
Transport of RNAs within nuclei and through nuclear pore complexes (NPCs) are essential, but poorly understood, steps in gene expression. In experiments with mammalian cells, RCC1, the abundant nuclear guanine nucleotide exchange factor for the guanosine triphosphatase Ran/TC4, was shown to be required for nucleocytoplasmic transport of precursors of spliceosomal small nuclear RNAs (snRNAs), intranuclear transport of U3 snRNA, and processing of ribosomal RNAs, but not for export of transfer RNAs. It is proposed that guanosine triphosphate (GTP)-bound Ran/TC4 associates with ribonucleoprotein particles (RNPs) during intranuclear movement, and that GTP hydrolysis promotes deposition of RNPs at targeted sites such as NPCs or nucleoli.
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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Biological Transport / physiology
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Cell Cycle Proteins*
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Cell Line
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Cell Nucleus / metabolism*
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DNA-Binding Proteins / physiology*
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Guanine Nucleotide Exchange Factors*
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Guanosine Triphosphate / metabolism
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Methylation
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Nuclear Proteins / metabolism
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Nuclear Proteins / physiology*
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RNA / metabolism*
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RNA Precursors / metabolism
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RNA, Ribosomal / metabolism
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RNA, Small Nuclear / metabolism
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RNA, Transfer / metabolism
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Spliceosomes / metabolism
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ran GTP-Binding Protein
Substances
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Cell Cycle Proteins
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DNA-Binding Proteins
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Guanine Nucleotide Exchange Factors
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Nuclear Proteins
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RNA Precursors
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RNA, Ribosomal
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RNA, Small Nuclear
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RNA
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Guanosine Triphosphate
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RNA, Transfer
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ran GTP-Binding Protein