RGD Reference Report - Gradient of increasing affinity of importin beta for nucleoporins along the pathway of nuclear import. - Rat Genome Database

Send us a Message



Submit Data |  Help |  Video Tutorials |  News |  Publications |  Download |  REST API |  Citing RGD |  Contact   

Gradient of increasing affinity of importin beta for nucleoporins along the pathway of nuclear import.

Authors: Ben-Efraim, I  Gerace, L 
Citation: Ben-Efraim I and Gerace L, J Cell Biol. 2001 Jan 22;152(2):411-7.
RGD ID: 9831195
Pubmed: PMID:11266456   (View Abstract at PubMed)
PMCID: PMC2199621   (View Article at PubMed Central)

Nuclear import and export signals on macromolecules mediate directional, receptor-driven transport through the nuclear pore complex (NPC) by a process that is suggested to involve the sequential binding of transport complexes to different nucleoporins. The directionality of transport appears to be partly determined by the nucleocytoplasmic compartmentalization of components of the Ran GTPase system. We have analyzed whether the asymmetric localization of discrete nucleoporins can also contribute to transport directionality. To this end, we have used quantitative solid phase binding analysis to determine the affinity of an importin beta cargo complex for Nup358, the Nup62 complex, and Nup153, which are in the cytoplasmic, central, and nucleoplasmic regions of the NPC, respectively. These nucleoporins are proposed to provide progressively more distal binding sites for importin beta during import. Our results indicate that the importin beta transport complex binds to nucleoporins with progressively increasing affinity as the complex moves from Nup358 to the Nup62 complex and to Nup153. Antibody inhibition studies support the possibility that importin beta moves from Nup358 to Nup153 via the Nup62 complex during import. These results indicate that nucleoporins themselves, as well as the nucleocytoplasmic compartmentalization of the Ran system, are likely to play an important role in conferring directionality to nuclear protein import.



Gene Ontology Annotations    Click to see Annotation Detail View

Biological Process

  
Object SymbolSpeciesTermQualifierEvidenceWithNotesSourceOriginal Reference(s)
Nup62Ratprotein import into nucleus  IMP  RGD 

Molecular Function

  
Object SymbolSpeciesTermQualifierEvidenceWithNotesSourceOriginal Reference(s)
Nup153Ratprotein binding  IPIKpnb1 (Rattus norvegicus) RGD 
Nup54Ratprotein binding  IPIKPNB1 (Homo sapiens) RGD 
Nup58Ratprotein binding  IPIKPNB1 (Homo sapiens) RGD 
Nup62Ratprotein binding  IPIKPNB1 (Homo sapiens) RGD 

Objects Annotated

Genes (Rattus norvegicus)
Nup153  (nucleoporin 153)
Nup54  (nucleoporin 54)
Nup58  (nucleoporin 58)
Nup62  (nucleoporin 62)


Additional Information