RanBP1 is a Ran/TC4 binding protein that can promote the interaction between Ran and beta-importin /beta-karyopherin, a component of the docking complex for nuclear protein cargo. This interaction occurs through a Ran binding domain (RBD). Here we show that RanBP1 is primarily cytoplasmic, but the isolated RBD accumulates in the nucleus. A region COOH-terminal to the RBD is responsible for this cytoplasmic localization. This domain acts heterologously, localizing a nuclear cyclin B1 mutant to the cytoplasm. The domain contains a nuclear export signal that is necessary but not sufficient for the nuclear export of a functional RBD In transiently transfected cells, epitope-tagged RanBP1 promotes dexamethasone-dependent nuclear accumulation of a glucocorticoid receptor-green fluorescent protein fusion, but the isolated RBD potently inhibits this accumulation. The cytosolic location of RanBP1 may therefore be important for nuclear protein import. RanBP1 may provide a key link between the nuclear import and export pathways.
Article|
September 01 1996
A nuclear export signal is essential for the cytosolic localization of the Ran binding protein, RanBP1.
S A Richards,
S A Richards
Department of Pathology, University of Vermont, Burlington 05405-0068, USA. srichard@moose.uvm.edu
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K M Lounsbury,
K M Lounsbury
Department of Pathology, University of Vermont, Burlington 05405-0068, USA. srichard@moose.uvm.edu
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K L Carey,
K L Carey
Department of Pathology, University of Vermont, Burlington 05405-0068, USA. srichard@moose.uvm.edu
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I G Macara
I G Macara
Department of Pathology, University of Vermont, Burlington 05405-0068, USA. srichard@moose.uvm.edu
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S A Richards
Department of Pathology, University of Vermont, Burlington 05405-0068, USA. srichard@moose.uvm.edu
K M Lounsbury
Department of Pathology, University of Vermont, Burlington 05405-0068, USA. srichard@moose.uvm.edu
K L Carey
Department of Pathology, University of Vermont, Burlington 05405-0068, USA. srichard@moose.uvm.edu
I G Macara
Department of Pathology, University of Vermont, Burlington 05405-0068, USA. srichard@moose.uvm.edu
Online ISSN: 1540-8140
Print ISSN: 0021-9525
J Cell Biol (1996) 134 (5): 1157–1168.
Citation
S A Richards, K M Lounsbury, K L Carey, I G Macara; A nuclear export signal is essential for the cytosolic localization of the Ran binding protein, RanBP1.. J Cell Biol 1 September 1996; 134 (5): 1157–1168. doi: https://doi.org/10.1083/jcb.134.5.1157
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