TY - JOUR
T1 - Cloning and characterization of human karyopherin β3
AU - Yaseen, Nabeel R.
AU - Blobel, Günter
PY - 1997/4/29
Y1 - 1997/4/29
N2 - Nuclear import of classical nuclear localization sequence-bearing proteins is mediated by karyopherin α/β1 heterodimers. A second nuclear import pathway, mediated by karyopherin β2 (transportin), recently was described for mRNA-binding proteins. Here we report the cloning and characterization of human karyopherin β3, which may be involved in a third pathway for nuclear import. Karyopherin β3 was localized mainly to the cytosol and the nucleus, particularly the nuclear rim. It bound to several of the repeat-containing nucleoporins (Nup358, Nup214, Nup153, Nup98, and p62) in overlay and solution-binding assays and was competed away by karyopherin β1. For Nup98, we localized this binding to the peptide repeat-containing region. Karyopherin β3 contains two putative Ran-binding homology regions and bound to RAN-GTP in a solution-binding assay with much higher affinity than to Ran-GDP. Furthermore, it interacted with two ribosomal proteins in an overlay assay. We suggest that karyopherin β3 is a nuclear transport factor that may mediate the import of some ribosomal proteins into the nucleus.
AB - Nuclear import of classical nuclear localization sequence-bearing proteins is mediated by karyopherin α/β1 heterodimers. A second nuclear import pathway, mediated by karyopherin β2 (transportin), recently was described for mRNA-binding proteins. Here we report the cloning and characterization of human karyopherin β3, which may be involved in a third pathway for nuclear import. Karyopherin β3 was localized mainly to the cytosol and the nucleus, particularly the nuclear rim. It bound to several of the repeat-containing nucleoporins (Nup358, Nup214, Nup153, Nup98, and p62) in overlay and solution-binding assays and was competed away by karyopherin β1. For Nup98, we localized this binding to the peptide repeat-containing region. Karyopherin β3 contains two putative Ran-binding homology regions and bound to RAN-GTP in a solution-binding assay with much higher affinity than to Ran-GDP. Furthermore, it interacted with two ribosomal proteins in an overlay assay. We suggest that karyopherin β3 is a nuclear transport factor that may mediate the import of some ribosomal proteins into the nucleus.
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U2 - 10.1073/pnas.94.9.4451
DO - 10.1073/pnas.94.9.4451
M3 - Article
C2 - 9114010
AN - SCOPUS:0030984329
VL - 94
SP - 4451
EP - 4456
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
SN - 0027-8424
IS - 9
ER -