title: Importin alpha: a multipurpose nuclear-transport receptor.
abstract: The importin alpha/beta heterodimer targets hundreds of proteins to the nuclear-pore complex (NPC) and facilitates their translocation across the nuclear envelope. Importin alpha binds to classical nuclear localization signal (cNLS)-containing proteins and links them to importin beta, the karyopherin that ferries the ternary complex through the NPC. A second karyopherin, the exportin CAS, recycles importin alpha back to the cytoplasm. In this article, we discuss control mechanisms that importin alpha exerts over the assembly and disassembly of the ternary complex and we describe how new groups of importin alpha genes arose during the evolution of metazoan animals to function in development and differentiation. We also describe activities of importin alpha that seem to be distinct from its housekeeping functions in nuclear transport.
authors.affiliation: Department of Biology, University of Rochester, Rochester, NY 14627, USA. dasg@mail.rochester.edu
authors.forename: David S
authors.initials: DS
authors.lastname: Goldfarb
authors.forename: Anita H
authors.initials: AH
authors.lastname: Corbett
authors.forename: D Adam
authors.initials: DA
authors.lastname: Mason
authors.forename: Michelle T
authors.initials: MT
authors.lastname: Harreman
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Adam
mesh_terms: D021581:Active Transport, Cell Nucleus; D000818:Animals; D017173:Caenorhabditis elegans; D002454:Cell Differentiation; D002467:Cell Nucleus / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism; D019281:Dimerization; D004330:Drosophila; D006801:Humans; D028884:Karyopherins / Q000737:chemistry; D008958:Models, Molecular; D010802:Phylogeny; D011487:Protein Conformation; D028901:alpha Karyopherins / Q000378:metabolism*; D028961:beta Karyopherins / Q000737:chemistry* / Q000378:metabolism
chemical_list: D028884:Karyopherins; D028901:alpha Karyopherins; D028961:beta Karyopherins