Assembles a suppression complex (suppresome) by tethering SIRT1 and MDM2 to regulate composite modifications of p53/TP53. Confers both deacetylation-mediated functional inactivation, by SIRT1, and ubiquitination-dependent degradation, by MDM2, of p53/TP53, promoting a proliferative and cell survival behaviors (PubMed:29681526). May play a role in the regulation of spermatogenesis (By similarity). . This is the function of MORN3 (MORN repeat containing 3, Ensembl gene identifier ENSG00000139714).