The activity of pro apoptotic proteins is tightly regulated at multiple levels, including transcriptional, post-transcriptional, and post-translational modifications. For instance, the tumor suppressor protein p53 can transcriptionally upregulate the expression of several pro apoptotic genes such as Bax and Puma in response to cellular stress or DNA damage. Additionally, pro apoptotic proteins can undergo phosphorylation, ubiquitination, and cleavage, which modulate their stability and activity.
