Final answer:
A nuclear localization signal (NLS) is a sequence of amino acids in a protein that directs the protein to be transported into the nucleus of a cell. The NLS becomes attached to a protein during synthesis and is recognized by cellular factors. Once the protein reaches the nucleus, the NLS is usually clipped off.
Step-by-step explanation:
A nuclear localization signal (NLS) is a sequence of amino acids in a protein that directs the protein to be transported into the nucleus of a cell. It is typically rich in positively charged amino acids such as lysine and arginine.
The NLS becomes attached to a protein during synthesis. The signal sequence is recognized by specific cellular factors, which help transport the protein from the cytoplasm to the nucleus. Once the protein reaches the nucleus, the NLS is usually clipped off.