Importin-13 is a protein encoded by the IPO13 gene in humans. Importin-13 is a member of the importin-β family of nuclear transport receptors (NTRs) and was first identified as a transport receptor in 2000. According to PSI-blast based secondary structure PREDiction (PSIPRED), importin-13 contains 38 α-helices. Importin-13 accommodates a range of cargoes due to its flexible superhelical structure and a cargo binding and release system that is distinct from other importin-like transport receptors. IPO13 is broadly expressed in a variety of tissues in the human body, including the heart, cornea, fetal lung, brain, endometrial carcinoma, and testes.
