Importin-13 (IPO13)

Importin-13 (IPO13) is a unique member of the importin-β/Karyopherin superfamily that functions as a nuclear transport receptor, mediating both the import and export of a variety of cargo proteins across the nuclear envelope in a Ran-dependent (and sometimes Ran-independent) manner. IPO13 directs the nucleocytoplasmic trafficking of key regulatory proteins—including transcription factors like glucocorticoid receptor, SP1, KLF4, homeodomain proteins Pax6, ARX, UBC9, and others—integral to anti-inflammatory signaling, stress response, gene expression, and cell fate decisions. Unlike most importins, IPO13 is active even under cellular stress, controlling nuclear import (e.g., of nCLU, which promotes apoptosis) and regulating export (e.g., KU70, involved in DNA repair). IPO13 thereby influences the response to oxidative stress, cell cycle progression, and apoptosis, and its altered function or genetic mutations can contribute to developmental abnormalities and disease. Phosphorylation of IPO13 further modulates its subcellular localization and transport activity, with implications for distribution of transcription partners such as Pax6 in development[1][2][3][4][5].

Other names

Importin-13IPO13KIAA0724RANBP13Imp13Kap13RanBP13IMP13KAP13LGL2late gestation lung 2Karyopherin-13Ran-binding protein 13Ran binding protein 13

Not applicable/none known for drugs, but as a transporter, IPO13 mediates nuclear import of proteins such as UBC9, Pax6, Pax3, CRX, ARX, glucocorticoid receptor, and nuclear export of eIF1A, EIF4G2, HMG20A, KLF4, and SP1