EGCG binds intrinsically disordered N-terminal domain of p53 and disrupts p53-MDM2 interaction

Jing Zhao,Stewart N Loh,Yingkai Zhang,Sozanne R Solmaz,David Ban,Weihua Jin,Xiaorong Liu,Ashley J Canning,Lufeng Yan,Xinyue Liu,Jianhan Chen,Alan Blayney,Lauren Gandy,Chao Yang,Yuanyuan Xiao,Chunyu Wang,Michael S Cosgrove,Jeung-Hoi Ha,Michael Connelly

doi:10.1038/s41467-021-21258-5

Abstract

Epigallocatechin gallate (EGCG) from green tea can induce apoptosis in cancerous cells, but the underlying molecular mechanisms remain poorly understood. Using SPR and NMR, here we report a direct, μM interaction between EGCG and the tumor suppressor p53 (KD = 1.6 ± 1.4 μM), with the disordered N-terminal domain (NTD) identified as the major binding site (KD = 4 ± 2 μM). Large scale atomistic simulations (>100 μs), SAXS and AUC demonstrate that EGCG-NTD interaction is dynamic and EGCG causes the emergence of a subpopulation of compact bound conformations. The EGCG-p53 interaction disrupts p53 interaction with its regulatory E3 ligase MDM2 and inhibits ubiquitination of p53 by MDM2 in an in vitro ubiquitination assay, likely stabilizing p53 for anti-tumor activity. Our work provides insights into the mechanisms for EGCG’s anticancer activity and identifies p53 NTD as a target for cancer drug discovery through dynamic interactions with small molecules.

Highlights

Epigallocatechin gallate (EGCG) from green tea can induce apoptosis in cancerous cells, but the underlying molecular mechanisms remain poorly understood
EGCG–p53 interaction was studied using a sensor chip immobilized with full-length p53 or p53 N-terminal domain (NTD)
The two dissociation constants are within measurement error, indicating that NTD is the major mediator of the p53–EGCG interaction

Summary

Introduction

Epigallocatechin gallate (EGCG) from green tea can induce apoptosis in cancerous cells, but the underlying molecular mechanisms remain poorly understood. Using SPR and NMR, here we report a direct, μM interaction between EGCG and the tumor suppressor p53 (KD = 1.6 ± 1.4 μM), with the disordered N-terminal domain (NTD) identified as the major binding site (KD = 4 ± 2 μM). The anti-cancer effect of EGCG has been demonstrated in epidemiological, cell culture, and animal studies, and in clinical trials[5]. Independent of ubiquitylation, MDM2 inhibits transcription by preventing general transcription factors from binding to NTD27. The apoptosis effect of EGCG on human cancer cells was associated with its interference of MDM2-mediated p53 ubiquitylation[28]. The molecular mechanism of how EGCG disrupts MDM2–p53 interaction is not yet understood

Methods

Results

Conclusion