[Nuclear pore-targeting complex/importin family]

Abstract

Transport of proteins into the nucleus is essential for many cellular functions to proceed. Nuclear import of proteins is directed by short amino acid sequence termed nuclear localization signals (NLS). The process of nuclear import is highly selective, requires energy, and is mediated by several soluble/cytoplasmic factors. At the entry to the import pathway, nuclear proteins form a stable complex, termed nuclear pore-targeting complex (PTAC). The complex consists of a nuclear protein and two cytosolic factors termed PTAC58 (importin alpha) and PTAC97 (importin beta). This report describes the function of PTAC/importin as well as their recently identified family proteins.