Nuclear Receptor PXR Confers Irradiation Resistance by Promoting DNA Damage Response Through Stabilization of ATF3.

ABSTRACT: Low response rate to radiotherapy remains a problem for liver and colorectal cancer patients due to inappropriate DNA damage response in tumors. Here, we report that pregnane X receptor (PXR) contributes to irradiation (IR) resistance by promoting activating transcription factor 3 (ATF3)-mediated ataxia-telangiectasia-mutated protein (ATM) activation. PXR stabilized ATF3 protein by blocking its ubiquitination. PXR-ATF3 interaction is required for regulating ATF3, as one mutant of lysine (K) 42R of ATF3 lost binding with PXR and abolished PXR-reduced ubiquitination of ATF3. On the other hand, threonine (T) 432A of PXR lost binding with ATF3 and further compromised ATM activation. Moreover, the PXR-ATF3 interaction increases ATF3 stabilization through disrupting ATF3-murine double minute 2 (

SUBMITTER: Niu X 

PROVIDER: S-EPMC8965888 | biostudies-literature | 2022

REPOSITORIES: biostudies-literature