Nucleolar protein, Myb-binding protein 1A, specifically binds to nonacetylated p53 and efficiently promotes transcriptional activation

Biochem Biophys Res Commun. 2013 May 10;434(3):659-63. doi: 10.1016/j.bbrc.2013.04.006. Epub 2013 Apr 11.


Nucleolar dynamics are important for cellular stress response. We previously demonstrated that nucleolar stress induces nucleolar protein Myb-binding protein 1A (MYBBP1A) translocation from the nucleolus to the nucleoplasm and enhances p53 activity. However, the underlying molecular mechanism is understood to a lesser extent. Here we demonstrate that MYBBP1A interacts with lysine residues in the C-terminal regulatory domain region of p53. MYBBP1A specifically interacts with nonacetylated p53 and induces p53 acetylation. We propose that MYBBP1A dissociates from acetylated p53 because MYBBP1A did not interact with acetylated p53 and because MYBBP1A was not recruited to the p53 target promoter. Therefore, once p53 is acetylated, MYBBP1A dissociates from p53 and interacts with nonacetylated p53, which enables another cycle of p53 activation. Based on our observations, this MYBBP1A-p53 binding property can account for efficient p53-activation by MYBBP1A under nucleolar stress. Our results support the idea that MYBBP1A plays catalytic roles in p53 acetylation and activation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylation
  • Amino Acid Sequence
  • Base Sequence
  • Cell Line, Tumor
  • Chromatin Immunoprecipitation
  • DNA Primers
  • DNA-Binding Proteins
  • Humans
  • Molecular Sequence Data
  • Nuclear Proteins / metabolism*
  • Nucleocytoplasmic Transport Proteins / metabolism*
  • Promoter Regions, Genetic
  • RNA-Binding Proteins
  • Transcription Factors
  • Transcriptional Activation*
  • Tumor Suppressor Protein p53 / chemistry
  • Tumor Suppressor Protein p53 / metabolism*


  • DNA Primers
  • DNA-Binding Proteins
  • MYBBP1A protein, human
  • Nuclear Proteins
  • Nucleocytoplasmic Transport Proteins
  • RNA-Binding Proteins
  • Transcription Factors
  • Tumor Suppressor Protein p53