Karyopherin subunit alpha (KPNA) (KPNA)

Nuclear importin alpha, also known as karyopherin alpha (KPNA), is a critical adapter protein responsible for the recognition and transport of proteins into the cell nucleus (UniProt, P52294). It functions by binding to the nuclear localization signal (NLS) of cargo proteins and subsequently forming a heterodimer with importin beta, which facilitates passage through the nuclear pore complex (Wikipedia, Importin). This transport mechanism is essential for various cellular processes, including gene expression, signal transduction, and cell cycle progression. In the context of disease, many viruses, including SARS-CoV-2 and HIV-1, hijack importin alpha to transport viral proteins into the nucleus, thereby evading the host immune response or facilitating viral replication (PubMed, 32251768). Furthermore, the overexpression of specific importin alpha isoforms, such as KPNA2, is frequently observed in various cancers and is associated with increased tumor aggressiveness and poor clinical outcomes (PubMed, 26823732). Consequently, importin alpha has emerged as a significant therapeutic target, with drugs like ivermectin demonstrating the ability to inhibit its transport function and provide potential antiviral effects (PubMed, 22417684).

Other names

Importin alphaKaryopherin alphaSRP1RCH1Nuclear import receptor

Inhibition of the nuclear import of cargo proteins by blocking the nuclear localization signal (NLS) binding site or disrupting the formation of the importin alpha/beta heterodimer (PubMed, 22417684).