APOBEC3B Regulates cMyc Through Protein-Protein Interactions

APOBEC3 enzymes are known for their roles as deoxycytidine deaminases but have been shown to have deaminase independent functions mediated through protein-protein interactions. APOBEC3B (A3B) engages in these protein-protein interactions to dysregulate cMyc, an oncogene involved in tumor growth. Mass spectrometry showed that A3B interacts with two proteins, prefoldin 5 (PFD5) and HUWE1, both known cMyc regulators. Using a western blot, we were able to analyze the outcome on cMyc when either PFD5 or HUWE1 interacted with A3B. We repeated previous work that demonstrated that A3B inhibits the ability of prefoldin 5 (PFD5) to induce degradation of cMyc. Through further studies we were able to determine that HUWE1 stabilizes cMyc and the A3B-HUWE1 interaction exhibits further stabilization of cMyc. Altogether, the results demonstrate that further work is to be done in cancer cell lines to determine the consistency and relevance to cancer cell biology.