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From Proteopedia
Human karyopherin RanBP5 (isoform-1)
Structural highlights
FunctionIPO5_HUMAN Functions in nuclear protein import as nuclear transport receptor. Serves as receptor for nuclear localization signals (NLS) in cargo substrates. Is thought to mediate docking of the importin/substrate complex to the nuclear pore complex (NPC) through binding to nucleoporin and the complex is subsequently translocated through the pore by an energy requiring, Ran-dependent mechanism. At the nucleoplasmic side of the NPC, Ran binds to the importin, the importin/substrate complex dissociates and importin is re-exported from the nucleus to the cytoplasm where GTP hydrolysis releases Ran. The directionality of nuclear import is thought to be conferred by an asymmetric distribution of the GTP- and GDP-bound forms of Ran between the cytoplasm and nucleus (By similarity). Mediates the nuclear import of ribosomal proteins RPL23A, RPS7 and RPL5. Binds to a beta-like import receptor binding (BIB) domain of RPL23A. In vitro, mediates nuclear import of H2A, H2B, H3 and H4 histones. Binds to CPEB3 and mediates its nuclear import following neuronal stimulation (By similarity). In case of HIV-1 infection, binds and mediates the nuclear import of HIV-1 Rev.[UniProtKB:Q8BKC5][1] Publication Abstract from PubMedHere, we describe the crystal structures of two distinct isoforms of ligand-free human karyopherin RanBP5 and investigate its global propensity to interact with influenza A virus polymerase. Our results confirm the general architecture and mechanism of the IMB3 karyopherin-beta subfamily whilst also highlighting differences with the yeast orthologue Kap121p. Moreover, our results provide insight into the structural flexibility of beta-importins in the unbound state. Based on docking of a nuclear localisation sequence, point mutations were designed, which suppress influenza PA-PB1 subcomplex binding to RanBP5 in a binary protein complementation assay. X-ray Structure of the Human Karyopherin RanBP5, an Essential Factor for Influenza Polymerase Nuclear Trafficking.,Swale C, Da Costa B, Sedano L, Garzoni F, McCarthy AA, Berger I, Bieniossek C, Ruigrok RWH, Delmas B, Crepin T J Mol Biol. 2020 Mar 25. pii: S0022-2836(20)30254-0. doi:, 10.1016/j.jmb.2020.03.021. PMID:32222384[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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