Figure 6.

Proposed model for the coordinated regulation of differentiation and apoptosis by MyoD and p53. MyoD is well known as a pioneer transcription factor responsible for the differentiation of skeletal myoblasts. MyoD drives transcription necessary for differentiation through both direct (A) and indirect (B) binding to DNA. p53 is well known for its role in tumor suppression as a pivotal transcription factor responsible for interpreting the extent of DNA damage into either cell cycle arrest or apoptosis (C). Shown are two examples where both p53 and MyoD sites have been confirmed. We propose that post-translational modification(s) or distinct binding partners, portrayed herein as shape changes, could explain the mutually exclusive, dual, biological roles in differentiation or apoptosis for both of these key transcription factors.