hMad4, c-Myc endogenous inhibitor, induces a replicative senescence-like state when overexpressed in human fibroblasts.

Mad family proteins have an antagonistic action on Myc-dependent cell proliferation and transformation. We isolated a human cDNA clone, human Mad4 (hMad4), encoding a polypeptide of 209 amino acid residues, exhibiting 90% identity with mouse Mad4. Northern blot analysis shows that hMad4 probe hybridizes to a 3.