Mitotic regulator protein RCC1 is complexed with a nuclear ras-related polypeptide.
We previously reported the purification of a complex of two proteins from human chromatin, consisting of a 47-kDa component called RCC1, which is a negative regulator of mitosis, and a 25-kDa protein. Here we show that the 25-kDa protein has a ras-related sequence. It binds guanine nucleotides, and excess Mg2+ and GDP or GTP dissociate the complex. Immunofluorescence studies and biochemical properties indicate that this polypeptide, in contrast to most members of the Ras family, is present in the nucleoplasm as a soluble monomer, in 25-fold excess over the complexed form. We designate this polypeptide Ran, for ras-related nuclear protein.
Bischoff
F R
FR
Project Molecular Biology of Mitosis, Deutsches Krebsforschungszentrum, Heidelberg, Federal Republic of Germany.
Ponstingl
H
H
D000595:Amino Acid Sequence; D001483:Base Sequence; D015153:Blotting, Western; D018797:Cell Cycle Proteins; D002850:Chromatography, Gel; D004273:DNA, Neoplasm / Q000032:analysis; D004268:DNA-Binding Proteins / Q000032:analysis / Q000302:isolation & purification / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D005455:Fluorescent Antibody Technique; D019204:GTP-Binding Proteins / Q000378:metabolism*; D020662:Guanine Nucleotide Exchange Factors; D006153:Guanosine Diphosphate / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D007700:Kinetics; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009687:Nuclear Proteins / Q000032:analysis / Q000302:isolation & purification / Q000378:metabolism*; D011485:Protein Binding; D012689:Sequence Homology, Nucleic Acid; D020931:ran GTP-Binding Protein
D018797:Cell Cycle Proteins; D004273:DNA, Neoplasm; D004268:DNA-Binding Proteins; D020662:Guanine Nucleotide Exchange Factors; D046911:Macromolecular Substances; D009687:Nuclear Proteins; C062521:RCC1 protein, human; D006153:Guanosine Diphosphate; D006160:Guanosine Triphosphate; D019204:GTP-Binding Proteins; D020931:ran GTP-Binding Protein