Role of post-translational modifications in regulating c-Myc proteolysis, transcriptional activity and biological...

Area of Science:

• Molecular Biology
• Cell Biology
• Oncology

Background:

• Myc proteins are central regulators of cell proliferation, differentiation, apoptosis, and tumorigenesis.
• The precise molecular mechanisms and interplay of c-Myc functions remain incompletely understood.
• The role of post-translational modifications (PTMs) in regulating c-Myc properties is controversial and requires clarification.

Purpose of the Study:

• To critically evaluate evidence on PTMs, specifically phosphorylation and ubiquitination, of the N-terminal domain of c-Myc.
• To elucidate how these PTMs contribute to the diverse biological functions of c-Myc.
• To propose a model integrating the roles of phosphorylation and ubiquitination in c-Myc-mediated processes.

Main Methods:

• Comprehensive review and critical evaluation of existing scientific literature.
• Focus on studies investigating phosphorylation and ubiquitination of the N-terminal transcriptional regulatory domain of c-Myc.
• Synthesis of evidence to address controversies in c-Myc regulation by PTMs.

Main Results:

• Phosphorylation of c-Myc's N-terminal domain has shown variable effects on apoptosis, tumorigenesis, proteolysis, and cellular transformation.
• Ubiquitination also significantly influences c-Myc's molecular and biological activities.
• An integrated model suggests PTMs are critical for cell cycle, growth, apoptosis, and tumorigenesis.

Conclusions:

• Phosphorylation and ubiquitination of c-Myc are critical regulators of cell cycle progression, cell growth, apoptosis, and tumorigenesis.
• These PTMs mediate their effects through phosphorylation-dependent transcriptional activation of specific gene sets and synchronized proteolysis.
• Understanding these PTMs offers insights into Myc's role in cancer and potential therapeutic strategies.