Human Importin Subunit Beta-1 (KPNB1) Protein

Background

KPNB1, also known as importin-β1, is a central nuclear transport receptor that mediates the translocation of proteins and RNA through the nuclear pore complex (NPC). It functions by binding cargo proteins either directly or through adaptor proteins such as karyopherin-α subunits. KPNB1 facilitates both nuclear import and export, utilizing Ran GTPase gradients to regulate transport directionality. It plays a key role in cellular processes such as gene regulation, mitosis, and stress responses. KPNB1 is widely expressed and is essential for embryonic development, cell cycle progression, and nucleocytoplasmic shuttling. Dysregulation of KPNB1 has been linked to cancer progression, where it enhances nuclear import of oncogenic transcription factors and survival regulators. It is also involved in viral replication, mediating the nuclear entry of viral proteins. Knockdown studies reveal its indispensability for cell viability, nuclear organization, and maintaining proper cellular function.