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A 41 amino acid motif in importin-alpha confers binding to importin-beta and hence transit into the nucleus.
Görlich D, Henklein P, Laskey RA, Hartmann E.
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The complex of importin-alpha and -beta is essential for nuclear protein import. It binds the import substrate in the cytosol, and the resulting trimeric complex moves through the nuclear pores, probably as a single entity. Importin-alpha provides the nuclear localization signal binding site, importin-beta the site of initial docking to the pore. Here we show that the conserved, basic N-terminus of importin-alpha is sufficient for importin-beta binding and essential for protein import. The fusion product of this 41 amino acid domain to a heterologous protein if transported into the nucleus in the same way as full-length importin-alpha itself. Transport is dependent on importin-beta but competed by importin-alpha. As no additional part of importin-alpha is needed for translocation, the movement which drives the import substrate complex into the nucleus appears to be generated between importin-beta and structures of the nuclear pore. The domain that binds to importin-beta appears to confer import only, but not re-export out of the nucleus, suggesting that the return of importin-alpha into the cytoplasm is not a simple reversal of its entry.
Adam,
Identification of cytosolic factors required for nuclear location sequence-mediated binding to the nuclear envelope.
1994, Pubmed
Adam,
Identification of cytosolic factors required for nuclear location sequence-mediated binding to the nuclear envelope.
1994,
Pubmed Adam,
Nuclear protein import in permeabilized mammalian cells requires soluble cytoplasmic factors.
1990,
Pubmed
,
Xenbase Adam,
Cytosolic proteins that specifically bind nuclear location signals are receptors for nuclear import.
1991,
Pubmed Andrade,
HEAT repeats in the Huntington's disease protein.
1995,
Pubmed Chi,
Sequence and characterization of cytoplasmic nuclear protein import factor p97.
1995,
Pubmed Cortes,
RAG-1 interacts with the repeated amino acid motif of the human homologue of the yeast protein SRP1.
1994,
Pubmed Cuomo,
Rch1, a protein that specifically interacts with the RAG-1 recombination-activating protein.
1994,
Pubmed Dingwall,
A polypeptide domain that specifies migration of nucleoplasmin into the nucleus.
1982,
Pubmed
,
Xenbase Feldherr,
Movement of a karyophilic protein through the nuclear pores of oocytes.
1984,
Pubmed
,
Xenbase Görlich,
Isolation of a protein that is essential for the first step of nuclear protein import.
1994,
Pubmed
,
Xenbase Görlich,
Two different subunits of importin cooperate to recognize nuclear localization signals and bind them to the nuclear envelope.
1995,
Pubmed
,
Xenbase Görlich,
Distinct functions for the two importin subunits in nuclear protein import.
1995,
Pubmed
,
Xenbase Hall,
Targeting of E. coli beta-galactosidase to the nucleus in yeast.
1984,
Pubmed Imamoto,
In vivo evidence for involvement of a 58 kDa component of nuclear pore-targeting complex in nuclear protein import.
1995,
Pubmed
,
Xenbase Imamoto,
A karyophilic protein forms a stable complex with cytoplasmic components prior to nuclear pore binding.
1995,
Pubmed Imamoto,
The nuclear pore-targeting complex binds to nuclear pores after association with a karyophile.
1995,
Pubmed Kalderon,
A short amino acid sequence able to specify nuclear location.
1984,
Pubmed Lanford,
Construction and characterization of an SV40 mutant defective in nuclear transport of T antigen.
1984,
Pubmed Melchior,
Inhibition of nuclear protein import by nonhydrolyzable analogues of GTP and identification of the small GTPase Ran/TC4 as an essential transport factor.
1993,
Pubmed Mills,
An acidic protein which assembles nucleosomes in vitro is the most abundant protein in Xenopus oocyte nuclei.
1980,
Pubmed
,
Xenbase Moore,
The GTP-binding protein Ran/TC4 is required for protein import into the nucleus.
1993,
Pubmed
,
Xenbase Moore,
The two steps of nuclear import, targeting to the nuclear envelope and translocation through the nuclear pore, require different cytosolic factors.
1992,
Pubmed
,
Xenbase Moore,
Purification of a Ran-interacting protein that is required for protein import into the nucleus.
1994,
Pubmed
,
Xenbase Moroianu,
Previously identified protein of uncertain function is karyopherin alpha and together with karyopherin beta docks import substrate at nuclear pore complexes.
1995,
Pubmed Moroianu,
Mammalian karyopherin alpha 1 beta and alpha 2 beta heterodimers: alpha 1 or alpha 2 subunit binds nuclear localization signal and beta subunit interacts with peptide repeat-containing nucleoporins.
1995,
Pubmed Newmeyer,
Nuclear import can be separated into distinct steps in vitro: nuclear pore binding and translocation.
1988,
Pubmed
,
Xenbase Paschal,
Identification of NTF2, a cytosolic factor for nuclear import that interacts with nuclear pore complex protein p62.
1995,
Pubmed Peifer,
A repeating amino acid motif shared by proteins with diverse cellular roles.
1994,
Pubmed Radu,
Identification of a protein complex that is required for nuclear protein import and mediates docking of import substrate to distinct nucleoporins.
1995,
Pubmed
,
Xenbase Richardson,
Nuclear protein migration involves two steps: rapid binding at the nuclear envelope followed by slower translocation through nuclear pores.
1988,
Pubmed
,
Xenbase Török,
The overgrown hematopoietic organs-31 tumor suppressor gene of Drosophila encodes an Importin-like protein accumulating in the nucleus at the onset of mitosis.
1995,
Pubmed
,
Xenbase Weis,
Identification of hSRP1 alpha as a functional receptor for nuclear localization sequences.
1995,
Pubmed Yano,
Cloning and characterization of SRP1, a suppressor of temperature-sensitive RNA polymerase I mutations, in Saccharomyces cerevisiae.
1992,
Pubmed
