Understanding the interaction of 14-3-3 proteins with hDMX and hDM2: a structural and biophysical study

Abstract

p53 plays a critical role in regulating diverse biological processes: DNA repair, cell cycle arrest, apoptosis, and senescence. The p53 pathway has therefore served as the focus for drug-discovery efforts. p53 is negatively regulated by hDMX and hDM2; prior studies have identified 14-3-3 proteins as hDMX and hDM2 client proteins. 14-3-3 proteins are adaptor proteins that modulate localisation, degradation and interactions of their targets in response to phosphorylation. Thus 14-3-3 proteins may indirectly modulate the interaction between hDMX or hDM2 and p53 and represent potential targets for modulation of the p53 pathway. In this manuscript we report on the biophysical and structural characterization of peptide/protein interactions that are representative of the interaction between 14-3-3 and hDMX or hDM2. The data establish that proximal phosphosites spaced ~20-25 residues apart in both hDMX and hDM2 co-operate to facilitate high-affinity 14-3-3 binding and provide structural insight that can be utilized in future stabilizer/inhibitor discovery efforts.

The MDM2 oncoprotein antagonizes Poly(ADP-ribosyl)ation

“…The N-terminal domain forms a hydrophobic pocket (AA25-100) that allows binding to p53 (Kussie et al, 1996). Even though multiple structures of MDM2 regions in complex with other proteins and compounds have been published in the past, the full-length structure has not yet been solved, and the N-terminal is the best characterized of all the domains (Grasberger et al, 2005;Kallen et al, 2009;Skalniak et al, 2019;Srdanovic et al, 2022).…”