KPNB1 Human

KPNB1 contains an importin N-terminal domain and 19 HEAT repeats, which are structural motifs involved in protein-protein interactions . The primary function of KPNB1 is to mediate the transport of proteins with a nuclear localization signal (NLS) from the cytoplasm into the nucleus. This process is essential for various cellular functions, including gene expression, DNA replication, and cell cycle regulation.

The transport mechanism involves the recognition of cargo proteins by KPNB1 in the cytoplasm. KPNB1 forms a complex with importin alpha, which directly binds to the NLS of the cargo protein. This complex is then transported through the nuclear pore complex (NPC) into the nucleus. Once inside the nucleus, the complex dissociates, releasing the cargo protein to perform its nuclear functions .

The Karyopherin-β family, to which KPNB1 belongs, has ancient origins and has continued to specialize throughout eukaryotic evolution. The family is highly conserved across different eukaryotic species, indicating its fundamental role in cellular processes. Studies have shown that at least fifteen Karyopherin-β subfamilies were established early in eukaryote evolution, highlighting the importance of nucleocytoplasmic transport mechanisms .

Recombinant human KPNB1 is produced using recombinant DNA technology, which involves inserting the gene encoding KPNB1 into a suitable expression system, such as bacteria or yeast. This allows for the large-scale production of KPNB1 for research and therapeutic purposes. Recombinant KPNB1 is typically supplied in a solution containing Tris-HCl buffer, DTT, glycerol, and NaCl to maintain its stability and activity .

Recombinant KPNB1 is widely used in research to study nucleocytoplasmic transport mechanisms, protein-protein interactions, and the regulation of nuclear import. It is also used in drug discovery and development to identify potential therapeutic targets for diseases related to nuclear transport dysfunction.