Nuclear localization signal (NLS)

Nuclear localization signal (NLS) refers to a short amino acid sequence (motif) found within proteins that need to be imported into the nucleus of a eukaryotic cell[2][3][4]. The NLS acts as a molecular tag, directing the protein for nuclear import. Proteins with an NLS are recognized by importin proteins and transported through the nuclear pore complex[2][3][4]. NLS motifs are typically enriched in basic residues (lysine, arginine), and are classified as either monopartite (a single stretch of basic amino acids, e.g., PKKKRKV) or bipartite (two clusters of basic amino acids separated by ~10 residues)[2][3]. The NLS is essential for the subcellular localization of numerous regulatory proteins, such as transcription factors, DNA repair enzymes, and cell cycle regulators[1][2][3][4]. Removal or mutation of the NLS impairs nuclear import; fusion of an NLS to cytosolic proteins is sufficient to direct their import into the nucleus[3][1]. Note: The NLS is not itself a molecule, receptor, or protein target, but rather a sequence motif found in many different nuclear-targeted proteins. Therefore, it is not considered a therapeutic target in the usual sense like enzymes, transporters, or receptors. It cannot directly interact with drugs and does not serve as a biomarker or disease role apart from the proteins that possess it. Any therapeutic or diagnostic applications would relate to the protein containing the NLS, not to the NLS motif itself[2][3][4].

Other names

nuclear localization sequenceNLSnuclear import signal