Karyopherin subunit alpha 1 (Importin subunit alpha-5) (KPNA1)

Karyopherin subunit alpha 1 (KPNA1, Importin subunit alpha-5) is a key adaptor protein in the classical nuclear import pathway, recognizing and binding nuclear localization signals (NLS) on cargo proteins, and bridging them to importin-beta (KPNB1) for energy-dependent translocation through the nuclear pore complex. KPNA1 is essential for the nuclear import of regulatory proteins involved in cell proliferation, apoptosis, and immune response, including phosphorylated STAT1 and p27. It also mediates the nuclear import of certain viral proteins and is antagonized by viral proteins to evade host immunity. KPNA1's function is critical in muscle satellite cell activation/quiescence and gene expression regulation, with its loss or dysfunction linked to diseases such as viral encephalitis, impaired immune response, and possibly cancer. Its role as a nuclear transporter makes it both a potential therapeutic target and a point of vulnerability for viral pathogens

Other names

Importin subunit alpha-5NPI-1RCH2SRP1IPOA5SRP1-betaKaryopherin alpha 1Importin-alpha-S1Nucleoprotein interactor 1RAG cohort protein 2

Competitive inhibition of cargo binding (e.g., viral antagonists such as Ebola VP24 compete with STAT1 for KPNA1 binding); Disruption of importin alpha/beta-dependent nuclear transport pathways; Targeting nuclear localization signal (NLS) binding on cargo proteins