Biophysical Characterization of Interactions Involving Importin-α during Nuclear Import

dc.contributorUniversidade Estadual Paulista (UNESP)
dc.creatorCatimel, Bruno
dc.creatorTeh, Trazel
dc.creatorFontes, Marcos R. M.
dc.creatorJennings, Ian G.
dc.creatorJans, David A.
dc.creatorHowlett, Geoffrey J.
dc.creatorNice, Edouard C.
dc.creatorKobe, Bostjan
dc.date2014-05-27T11:20:18Z
dc.date2016-10-25T18:17:10Z
dc.date2014-05-27T11:20:18Z
dc.date2016-10-25T18:17:10Z
dc.date2001-09-07
dc.date.accessioned2017-04-06T01:00:03Z
dc.date.available2017-04-06T01:00:03Z
dc.identifierJournal of Biological Chemistry, v. 276, n. 36, p. 34189-34198, 2001.
dc.identifier0021-9258
dc.identifierhttp://hdl.handle.net/11449/66582
dc.identifierhttp://acervodigital.unesp.br/handle/11449/66582
dc.identifier10.1074/jbc.M103531200
dc.identifier2-s2.0-0035823482
dc.identifierhttp://dx.doi.org/10.1074/jbc.M103531200
dc.identifier.urihttp://repositorioslatinoamericanos.uchile.cl/handle/2250/888126
dc.descriptionProteins containing the classical nuclear localization sequences (NLSs) are imported into the nucleus by the importin-α/β heterodimer. Importin-α contains the NLS binding site, whereas importin-β mediates the translocation through the nuclear pore. We characterized the interactions involving importin-α during nuclear import using a combination of biophysical techniques (biosensor, crystallography, sedimentation equilibrium, electrophoresis, and circular dichroism). Importin-α is shown to exist in a monomeric autoinhibited state (association with NLSs undetectable by biosensor). Association with importin-β (stoichiometry, 1:1; K D = 1.1 × 10 -8 M) increases the affinity for NLSs; the importin-α/β complex binds representative monopartite NLS (simian virus 40 large T-antigen) and bipartite NLS (nucleoplasmin) with affinities (K D = 3.5 × 10 -8 M and 4.8 × 10 -8 M, respectively) comparable with those of a truncated importin-α lacking the autoinhibitory domain (T-antigen NLS, K D = 1.7 × 10 -8 M; nucleoplasmin NLS, K D = 1.4 × 10 -8 M). The autoinhibitory domain (as a separate peptide) binds the truncated importin-α, and the crystal structure of the complex resembles the structure of full-length importin-α. Our results support the model of regulation of nuclear import mediated by the intrasteric autoregulatory sequence of importin-α and provide a quantitative description of the binding and regulatory steps during nuclear import.
dc.languageeng
dc.relationJournal of Biological Chemistry
dc.rightsinfo:eu-repo/semantics/closedAccess
dc.subjectisoprotein
dc.subjectkaryopherin
dc.subjectligand
dc.subjectnuclear protein
dc.subjectnucleoplasmin
dc.subjectphosphoprotein
dc.subjectkaryopherin alpha
dc.subjectvirus large T antigen
dc.subjectactive transport
dc.subjectanimal
dc.subjectbiological model
dc.subjectcell nucleus
dc.subjectchemical structure
dc.subjectchemistry
dc.subjectcircular dichroism
dc.subjectdimerization
dc.subjectEscherichia coli
dc.subjectgenetic procedures
dc.subjectkinetics
dc.subjectmetabolism
dc.subjectmouse
dc.subjectpeptide synthesis
dc.subjectphysiology
dc.subjectprotein binding
dc.subjectprotein tertiary structure
dc.subjecttime
dc.subjectultracentrifugation
dc.subjectX ray crystallography
dc.subjectanimal cell
dc.subjectbiosensor
dc.subjectcell interaction
dc.subjectcomplex formation
dc.subjectconformational transition
dc.subjectcrystallography
dc.subjectmolecular interaction
dc.subjectnonhuman
dc.subjectnuclear import
dc.subjectnucleocytoplasmic transport
dc.subjectpriority journal
dc.subjectprotein domain
dc.subjectprotein localization
dc.subjectreceptor affinity
dc.subjectstoichiometry
dc.subjectActive Transport, Cell Nucleus
dc.subjectAnimals
dc.subjectBiosensing Techniques
dc.subjectCell Nucleus
dc.subjectCircular Dichroism
dc.subjectCrystallography, X-Ray
dc.subjectDimerization
dc.subjectKaryopherins
dc.subjectKinetics
dc.subjectLigands
dc.subjectMice
dc.subjectModels, Biological
dc.subjectModels, Molecular
dc.subjectNuclear Proteins
dc.subjectPeptide Biosynthesis
dc.subjectPhosphoproteins
dc.subjectProtein Binding
dc.subjectProtein Isoforms
dc.subjectProtein Structure, Tertiary
dc.subjectTime Factors
dc.subjectUltracentrifugation
dc.subjectSimiae
dc.subjectSimian virus
dc.subjectSimian virus 40
dc.subjectAnimalia
dc.subjectComplexation
dc.subjectDimers
dc.subjectElectrophoresis
dc.subjectMonomers
dc.subjectProteins
dc.subjectNuclear localization sequences (NLS)
dc.subjectBiochemistry
dc.titleBiophysical Characterization of Interactions Involving Importin-α during Nuclear Import
dc.typeOtro


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