Final answer:
The tetracycline transactivator localizes to the nucleus through the use of a nuclear localization signal (NLS). The NLS is a short sequence of amino acids that acts as a molecular tag, allowing the protein to be recognized and transported into the nucleus.
Step-by-step explanation:
In order for the tetracycline transactivator to localize to the nucleus, it requires a nuclear localization signal (NLS). The NLS is a short sequence of amino acids that acts as a molecular tag, allowing the protein to be recognized and transported into the nucleus. The NLS of the tetracycline transactivator contains positively charged amino acids, such as lysine and proline, which enable binding to a nuclear transport receptor protein in the cytosol.