KPNB3 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. 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. In case of HIV-1 infection, binds and mediates the nuclear import of HIV-1 Rev. Belongs to the importin beta family. Importin beta-3 subfamily. 3 alternatively spliced human isoforms have been reported. Note: This description may include information from UniProtKB.
Protein type: Karyopherin; Nuclear import; Nucleolus
Chromosomal Location of human Ortholog: 13q32.2
Cellular Component:  cytoplasm; nuclear pore; nucleolus; nucleus
Molecular Function:  GTPase inhibitor activity; nuclear import signal receptor activity; nuclear localization sequence binding; protein binding; small GTPase binding
Biological Process:  cellular response to amino acid stimulus; negative regulation of cyclin-dependent protein serine/threonine kinase activity; NLS-bearing protein import into nucleus; positive regulation of protein import into nucleus; protein import into nucleus; ribosomal protein import into nucleus
Reference #:  O00410 (UniProtKB)
Alt. Names/Synonyms: DKFZp686O1576; FLJ43041; IMB3; Imp5; importin 5; importin beta-3 subunit; Importin subunit beta-3; Importin-5; IPO5; karyopherin (importin) beta 3; Karyopherin beta-3; KPNB3; MGC2068; Pse1; RAN binding protein 5; Ran-binding protein 5; Ran_GTP binding protein 5; RANBP5
Gene Symbols: IPO5
Molecular weight: 123,630 Da
Basal Isoelectric point: 4.83  Predict pI for various phosphorylation states
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Protein Structure Not Found.

Cross-references to other databases:  AlphaFold  |  STRING  |  cBioPortal  |  Wikipedia  |  neXtProt  |  Protein Atlas  |  BioGPS  |  Pfam  |  RCSB PDB  |  Phospho.ELM  |  NetworKIN  |  GeneCards  |  UniProtKB  |  Entrez-Gene  |  GenPept  |  Ensembl Gene