Final answer:
True. Some proteins are kept out of the nucleus until needed by inactivating their nuclear localization signals (NLS) through phosphorylation.
Step-by-step explanation:
True
Some proteins are kept out of the nucleus until needed by inactivating their nuclear localization signals (NLS) through phosphorylation. Nuclear localization signals are sequences of amino acids that target proteins to the nucleus.
hosphorylation, a process in which phosphate groups are added to proteins, can modify the structure and function of proteins, including their ability to enter the nucleus.