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Mol Cell Biol
1999 Nov 01;1911:7782-91. doi: 10.1128/MCB.19.11.7782.
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Evidence for distinct substrate specificities of importin alpha family members in nuclear protein import.
Köhler M
,
Speck C
,
Christiansen M
,
Bischoff FR
,
Prehn S
,
Haller H
,
Görlich D
,
Hartmann E
.
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Importin alpha plays a pivotal role in the classical nuclear protein import pathway. Importin alpha shuttles between nucleus and cytoplasm, binds nuclear localization signal-bearing proteins, and functions as an adapter to access the importin beta-dependent import pathway. In contrast to what is found for importin beta, several isoforms of importin alpha, which can be grouped into three subfamilies, exist in higher eucaryotes. We describe here a novel member of the human family, importin alpha7. To analyze specific functions of the distinct importin alpha proteins, we recombinantly expressed and purified five human importin alpha's along with importin alpha from Xenopus and Saccharomyces cerevisiae. Binding affinity studies showed that all importin alpha proteins from humans or Xenopus bind their import receptor (importin beta) and their export receptor (CAS) with only marginal differences. Using an in vitro import assay based on permeabilized HeLa cells, we compared the import substrate specificities of the various importin alpha proteins. When the substrates were tested singly, only the import of RCC1 showed a strong preference for one family member, importin alpha3, whereas most of the other substrates were imported by all importin alpha proteins with similar efficiencies. However, strikingly different substrate preferences of the various importin alpha proteins were revealed when two substrates were offered simultaneously.
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
Bischoff,
Catalysis of guanine nucleotide exchange on Ran by the mitotic regulator RCC1.
1991,
Pubmed
,
Xenbase
Chi,
Sequence and characterization of cytoplasmic nuclear protein import factor p97.
1995,
Pubmed
Conti,
Crystallographic analysis of the recognition of a nuclear localization signal by the nuclear import factor karyopherin alpha.
1998,
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
Dingwall,
Nuclear targeting sequences--a consensus?
1991,
Pubmed
Edelhoch,
Spectroscopic determination of tryptophan and tyrosine in proteins.
1967,
Pubmed
Fischer,
Epstein-Barr virus nuclear antigen 1 forms a complex with the nuclear transporter karyopherin alpha2.
1997,
Pubmed
Görlich,
Isolation of a protein that is essential for the first step of nuclear protein import.
1994,
Pubmed
,
Xenbase
Görlich,
Distinct functions for the two importin subunits in nuclear protein import.
1995,
Pubmed
,
Xenbase
Görlich,
A 41 amino acid motif in importin-alpha confers binding to importin-beta and hence transit into the nucleus.
1996,
Pubmed
,
Xenbase
Görlich,
Identification of different roles for RanGDP and RanGTP in nuclear protein import.
1996,
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,
Transport into and out of the cell nucleus.
1998,
Pubmed
Herold,
Determination of the functional domain organization of the importin alpha nuclear import factor.
1998,
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,
The nuclear pore-targeting complex binds to nuclear pores after association with a karyophile.
1995,
Pubmed
Jäkel,
Importin beta, transportin, RanBP5 and RanBP7 mediate nuclear import of ribosomal proteins in mammalian cells.
1998,
Pubmed
Johnsson,
Immobilization of proteins to a carboxymethyldextran-modified gold surface for biospecific interaction analysis in surface plasmon resonance sensors.
1991,
Pubmed
Köhler,
Cloning of two novel human importin-alpha subunits and analysis of the expression pattern of the importin-alpha protein family.
1997,
Pubmed
Kutay,
Export of importin alpha from the nucleus is mediated by a specific nuclear transport factor.
1997,
Pubmed
,
Xenbase
Kutay,
Dominant-negative mutants of importin-beta block multiple pathways of import and export through the nuclear pore complex.
1997,
Pubmed
,
Xenbase
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
Michael,
The K nuclear shuttling domain: a novel signal for nuclear import and nuclear export in the hnRNP K protein.
1997,
Pubmed
,
Xenbase
Miyamoto,
Differential modes of nuclear localization signal (NLS) recognition by three distinct classes of NLS receptors.
1997,
Pubmed
Moore,
Purification of a Ran-interacting protein that is required for protein import into the nucleus.
1994,
Pubmed
,
Xenbase
Moore,
Ran and nuclear transport.
1998,
Pubmed
Moore,
The GTP-binding protein Ran/TC4 is required for protein import into the nucleus.
1993,
Pubmed
,
Xenbase
Nachury,
Cloning and characterization of hSRP1 gamma, a tissue-specific nuclear transport factor.
1998,
Pubmed
Nadler,
Differential expression and sequence-specific interaction of karyopherin alpha with nuclear localization sequences.
1997,
Pubmed
Ohno,
Nucleocytoplasmic transport: the last 200 nanometers.
1998,
Pubmed
Ohtsubo,
The RCC1 protein, a regulator for the onset of chromosome condensation locates in the nucleus and binds to DNA.
1989,
Pubmed
Paschal,
Identification of NTF2, a cytosolic factor for nuclear import that interacts with nuclear pore complex protein p62.
1995,
Pubmed
Prieve,
Differential importin-alpha recognition and nuclear transport by nuclear localization signals within the high-mobility-group DNA binding domains of lymphoid enhancer factor 1 and T-cell factor 1.
1998,
Pubmed
Prieve,
The nuclear localization signal of lymphoid enhancer factor-1 is recognized by two differentially expressed Srp1-nuclear localization sequence receptor proteins.
1996,
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
Reid,
E1A directly binds and regulates the P/CAF acetyltransferase.
1998,
Pubmed
Ribbeck,
NTF2 mediates nuclear import of Ran.
1998,
Pubmed
Seki,
Cloning of a cDNA encoding a novel importin-alpha homologue, Qip1: discrimination of Qip1 and Rch1 from hSrp1 by their ability to interact with DNA helicase Q1/RecQL.
1997,
Pubmed
Sekimoto,
Extracellular signal-dependent nuclear import of Stat1 is mediated by nuclear pore-targeting complex formation with NPI-1, but not Rch1.
1997,
Pubmed
Tsuji,
Identification of novel homologues of mouse importin alpha, the alpha subunit of the nuclear pore-targeting complex, and their tissue-specific expression.
1997,
Pubmed
Weis,
The conserved amino-terminal domain of hSRP1 alpha is essential for nuclear protein import.
1996,
Pubmed
Weis,
Identification of hSRP1 alpha as a functional receptor for nuclear localization sequences.
1995,
Pubmed
