Role of the nuclear transport factor p10 in nuclear import.
The nuclear import factor p10 was cloned from Saccharomyces cerevisiae and found to be essential. The protein p10 can bind directly to several peptide repeat-containing nucleoporins. It also binds to the guanosine triphosphatase (GTPase) Ran in its guanosine diphosphate (GDP)-bound form and to karyopherin beta. Assembly of the karyopherin heterodimer on immobilized nucleoporin yielded cooperative binding of p10 and Ran-GDP. Addition of GTP to this pentameric complex led to dissociation of karyopherin (chi, presumably via in situ formation of Ran-GTP from Ran-GDP. Thus, p10 appears to coordinate the Ran-dependent association and dissociation reactions underlying nuclear import.
Nehrbass
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Laboratory of Cell Biology, Howard Hughes Medical Institute, Rockefeller University, New York 10021, USA.
Blobel
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D001693:Biological Transport, Active; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism*; D003001:Cloning, Molecular; D019204:GTP-Binding Proteins / Q000378:metabolism; D006153:Guanosine Diphosphate / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000378:metabolism; D008969:Molecular Sequence Data; D009685:Nuclear Envelope / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism*; D029543:Nucleocytoplasmic Transport Proteins; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D028901:alpha Karyopherins; D028961:beta Karyopherins; D020931:ran GTP-Binding Protein
D002352:Carrier Proteins; C499531:NTF2 protein, S cerevisiae; D009687:Nuclear Proteins; D029543:Nucleocytoplasmic Transport Proteins; D029701:Saccharomyces cerevisiae Proteins; D028901:alpha Karyopherins; D028961:beta Karyopherins; D006153:Guanosine Diphosphate; D006160:Guanosine Triphosphate; D019204:GTP-Binding Proteins; D020931:ran GTP-Binding Protein