RCC1 in the Ran pathway.
RCC1 is a chromosomal protein that functions as a GEF of the nuclear G protein Ran, which GTPase activity is enhanced by RNA1 located in the cytoplasm. RCC1 has no preference for GTP or GDP-bound Ran, so that GTP-Ran formation in vivo is regulated by relative concentrations of GTP/GDP and regulatory proteins interacting with RCC1, Ran, and RNA1. Proteins possessing the special Ran-binding motif have been found to be conserved in species ranging from yeasts to mammalians. The finding of RanBP2/NUP358 clearly indicates the involvement of the Ran pathway in the nuclear pore transport function, in agreement with the finding that both rcc1- and rna1- show defects in this process. However, loss of RCC1 induces premature initiation of mitosis, resulting in G1 arrest with the micronuclei possessing mitotic condensed chromosomes. How both the cell cycle and nucleocytoplasmic transport are regulated by the RCC1-Ran pathway is a major question.
Seki
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T
Department of Molecular Biology, Graduate School of Medical Science, Kyushu University, Fukuoka.
Hayashi
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N
Nishimoto
T
T
D000595:Amino Acid Sequence; D000818:Animals; D001693:Biological Transport, Active; D002453:Cell Cycle; D018797:Cell Cycle Proteins; D018076:DNA, Complementary / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004330:Drosophila / Q000235:genetics / Q000378:metabolism; D020558:GTP Phosphohydrolases / Q000378:metabolism; D019204:GTP-Binding Proteins / Q000378:metabolism; D020690:GTPase-Activating Proteins; D020662:Guanine Nucleotide Exchange Factors; D006801:Humans; D008969:Molecular Sequence Data; D009685:Nuclear Envelope / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism*; D011485:Protein Binding; D012091:Repetitive Sequences, Nucleic Acid; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D012568:Schizosaccharomyces / Q000235:genetics / Q000378:metabolism; D029702:Schizosaccharomyces pombe Proteins; D017386:Sequence Homology, Amino Acid; D020931:ran GTP-Binding Protein
D018797:Cell Cycle Proteins; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D020690:GTPase-Activating Proteins; D020662:Guanine Nucleotide Exchange Factors; D009687:Nuclear Proteins; C062521:RCC1 protein, human; C060997:RNA1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D029702:Schizosaccharomyces pombe Proteins; C499298:rna1 protein, S pombe; D020558:GTP Phosphohydrolases; D019204:GTP-Binding Proteins; D020931:ran GTP-Binding Protein