Akt-mediated RALY phosphorylation functions as a molecular switch governing c-Myc stability.

Source: PubMed, NCBI / U.S. National Library of Medicine

The oncoprotein c-Myc is frequently dysregulated in human cancers, yet the underlying mechanisms remain elusive. Here, we identify the RNA-binding protein RALY as a critical post-translational stabilizer of c-Myc. RALY homodimerizes and acts as a scaffold to bridge the deubiquitinating enzyme USP22 to c-Myc, thereby preventing c-Myc ubiquitination and proteasomal degradation. Under physiological growth factor stimulation, RALY is phosphorylated by Akt at S106 and T160. This phosphorylation event enables ternary complex formation with USP22 and c-Myc, promoting c-Myc stabilization and driving RALY's oncogenic activity. Furthermore, a synthetic peptide derived from RALY, termed RAMi, disrupts the RALY-USP22-c-Myc complex, destabilizes c-Myc, and exhibits potent anti-tumor effects. Together, these findings reveal Akt-mediated RALY phosphorylation as a molecular switch governing c-Myc stability and underscore the therapeutic potential of targeting the RALY-USP22-c-Myc axis in cancer.