importin alpha-7 subunit (karyopherin alpha-6 subunit, KPNA6, IPOA7)

Function

• nuclear protein import as an adapter protein for nuclear receptor KPNB1
• binds specifically & directly to substrates containing either a simple or bipartite NLS motif
• docking of the importin/substrate complex to the nuclear pore complex (NPC) is mediated by KPNB1 through binding to nucleoporin FxFG repeats
• the complex is subsequently translocated through the pore by an energy requiring, Ran- dependent mechanism
• at the nucleoplasmic side of the nuclear pore complex, Ran binds to importin-beta & the 3 components separate
• importin-alpha & importin-beta are re-exported from the nucleus to the cytoplasm where GTP hydrolysis releases Ran from importin
• directionality of nuclear import is thought to be conferred by an asymmetric distribution of the GTP- & GDP-bound forms of Ran between the cytoplasm & nucleus
• forms a complex with importin subunit beta-1

Structure

• belongs to the importin alpha family
• contains 10 ARM repeats
• contains 1 IBB domain

Expression

widely expressed

More general terms

• importin alpha subunit
• phosphoprotein

Additional terms

• importin complex (NLS-binding protein)

Database

• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:2363
• UniProt: http://www.uniprot.org/uniprot/O60684.html