IPO9
Description
The IPO9 (importin 9) is a protein-coding gene located on chromosome 1.
Importin-9 is a protein that in humans is encoded by the IPO9 gene.
Importin-9 (IPO9) is a nuclear transport receptor responsible for moving proteins into the nucleus, including histones, proteasomes, and actin. It recognizes and binds to nuclear localization signals (NLS) on its cargo, facilitating their entry into the nucleus. IPO9 interacts with nucleoporins, components of the nuclear pore complex (NPC), to dock the cargo and initiate its transport. This process is energy-dependent and involves the GTPase Ran. After translocation, Ran binds to IPO9, causing cargo release and the recycling of IPO9 back to the cytoplasm. IPO9 is crucial for the import of pre-assembled proteasomes, interacting with AKIRIN2 as a bridge to the complex. It specifically imports histones H2A, H2B, H4, and H4, acting as a chaperone to prevent inappropriate interactions. IPO9 also mediates the import of actin.
IPO9 is also known as Imp9.
