Influenza A virus nonstructural protein 1 (NS1A) is a multifunctional protein that exists as a dimer and is involved in the inhibition of host cell antiviral pre-mRNA processing and counteracts host cell antiviral responses. Unlike most other RNA viruses, influenza viruses replicate in the nucleus of the host cells. NS1A protein carries two nuclear localization signal (NLS) elements and these sequence elements are recognized by importin-alpha/beta. In the cytoplasm NS1A binds to importin-alpha/beta and these protein complexes are then translocated into the nucleus through the nuclear pore complex (NPC).
Note:Reactions directly involving interactions of human host proteins with foreign ones are highlighted in red.