Importin α
Class of adaptor proteins / From Wikipedia, the free encyclopedia
Importin alpha, or karyopherin alpha refers to a class of adaptor proteins that are involved in the import of proteins into the cell nucleus. They are a sub-family of karyopherin proteins.[1]
Importin α is known to bind to the nuclear localization signal (NLS) sequence of nucleus targeted proteins.[2] After this recognition, importin α links the protein to importin β, which transports the NLS-containing protein across the nuclear envelope to its destination.[3] Because of their complementary functional relationship, importin α and importin β are often referred to as the importin α/β heterodimer, but they are functionally separate, and do not normally exist in conjugation with each other, but only associate for cellular import processes, thus importin α proteins constitute an independent class of adaptor protein.