What is the fine-grained topic of the following text: The DNA-binding activity is cryptic but can be modulated through the C-terminal region of the p53 protein by several different stimuli, including phosphorylation by casein kinase II (CKII), protein kinase C (PKC) or binding of the C-terminal monoclonal antibody PAb421. Only return the topic.
Modulation of DNA-binding activity through the C-terminal region of the p53 protein.