MDMX acidic domain inhibits p53 DNA binding in vivo and regulates tumorigenesis

Qingling Huang, Lihong Chen, Leixiang Yang, Xiaoling Xie, Lin Gan, John L. Cleveland, Jiandong Chen

Research output: Contribution to journalArticlepeer-review

13 Scopus citations


The MDM2 homolog MDMX oncoprotein is indispensable for inhibition of p53 during normal embryonic development and malignant transformation, yet how MDMX harnesses p53 functions is unclear. In addition to a canonical N-terminal p53-binding domain, recent work suggests the central acidic domain of MDMX regulates p53 interaction through intramolecular mimicry and engages in second-site interaction with the p53 core domain in vitro. To test the physiological relevance of these interactions, we generated an MDMX knockin mouse having substitutions in a conserved WW motif necessary for these functions (W201S/W202G). Notably, MDMXSG cells have normal p53 level but increased p53 DNA binding and target gene expression, and rapidly senesce. In vivo, MDMXSG inhibits early-phase disease in Eμ-Myc transgenic mice but accelerates the onset of lethal lymphoma and shortens overall survival. Therefore, MDMX is an important regulator of p53 DNA binding, which complements the role of MDM2 in regulating p53 level. Furthermore, the results suggest that the WW motif has dual functions that regulate p53 and inhibit Myc-driven lymphomas independent of p53.

Original languageEnglish (US)
Pages (from-to)E3368-E3377
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number15
StatePublished - 2018
Externally publishedYes


  • CK1α
  • DNA binding
  • MDMX
  • Myc
  • P53

ASJC Scopus subject areas

  • General


Dive into the research topics of 'MDMX acidic domain inhibits p53 DNA binding in vivo and regulates tumorigenesis'. Together they form a unique fingerprint.

Cite this