Abstract
The Ran guanosine triphosphatase (GTPase) controls nucleocytoplasmic transport, mitotic spindle formation, and nuclear envelope assembly. These functions rely on the association of the Ran-specific exchange factor, RCC1 (regulator of chromosome condensation 1), with chromatin. We find that RCC1 binds directly to mononucleosomes and to histones H2A and H2B. RCC1 utilizes these histones to bind Xenopus sperm chromatin, and the binding of RCC1 to nucleosomes or histones stimulates the catalytic activity of RCC1. We propose that the docking of RCC1 to H2A/H2B establishes the polarity of the Ran-GTP gradient that drives nuclear envelope assembly, nuclear transport, and other nuclear events.
Publication types
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Active Transport, Cell Nucleus
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Animals
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Catalysis
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Cell Cycle Proteins*
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Cell Nucleus / metabolism
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Chickens
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Chromatin / metabolism*
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DNA / metabolism
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DNA-Binding Proteins / metabolism*
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Dimerization
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Guanine Nucleotide Exchange Factors*
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Guanosine Diphosphate / metabolism
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Guanosine Triphosphate / metabolism
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HeLa Cells
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Histones / metabolism*
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Humans
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Male
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Nuclear Envelope / metabolism
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Nuclear Proteins*
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Nucleosomes / metabolism*
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Recombinant Fusion Proteins / metabolism
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Spermatozoa
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Xenopus Proteins
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Xenopus laevis
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ran GTP-Binding Protein / metabolism
Substances
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Cell Cycle Proteins
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Chromatin
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DNA-Binding Proteins
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Guanine Nucleotide Exchange Factors
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Histones
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Nuclear Proteins
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Nucleosomes
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RCC1 protein, Xenopus
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RCC1 protein, human
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Recombinant Fusion Proteins
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Xenopus Proteins
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Guanosine Diphosphate
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Guanosine Triphosphate
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DNA
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ran GTP-Binding Protein