PML3 Orchestrates the Nuclear Dynamics and Function of TIP60

J Biol Chem. 2009 Mar 27;284(13):8747-59. doi: 10.1074/jbc.M807590200. Epub 2009 Jan 16.

Abstract

The promyelocytic leukemia (PML) protein is a major component to govern the PML nuclear body (NB) assembly and function. Although it is well defined that PML NB is a site recruiting sumoylated proteins, the mechanism by which PML protein regulates the process remains unclear. Here we show that PML3, a specific PML isoform, interacts with and recruits TIP60 to PML NBs. Our biochemical characterization demonstrates that PML3 physically interacts with TIP60 via its N-terminal 364 amino acids. Importantly, this portion of TIP60 is sufficient to target to the PML NBs, suggesting that PML3-TIP60 interaction is sufficient for targeting TIP60 to the NBs. The PML3-TIP60 interaction is specific, since the region of TIP60 binding is not conserved in other PML isoforms. The physical interaction between PML3 and TIP60 protects TIP60 from Mdm2-mediated degradation, suggesting that PML3 competes with MDM2 for binding to TIP60. Fluorescence recovery after photobleaching analysis indicates that the PML3-TIP60 interaction modulates the nuclear body distribution and mobility of TIP60. Conversely, the distribution and mobility of TIP60 are perturbed in PML3-deficient cells, accompanied by aberrations in DNA damage-repairing response. Thus, PML3 orchestrates the distribution, dynamics, and function of TIP60. Our findings suggest a novel regulatory mechanism by which the PML3 and TIP60 tumor suppressors cooperate to ensure genomic stability.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Nucleus / genetics
  • Cell Nucleus / metabolism*
  • Genomic Instability / physiology
  • HeLa Cells
  • Histone Acetyltransferases / genetics
  • Histone Acetyltransferases / metabolism*
  • Humans
  • Lysine Acetyltransferase 5
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*
  • Promyelocytic Leukemia Protein
  • Protein Binding / physiology
  • Protein Isoforms / genetics
  • Protein Isoforms / metabolism
  • Protein Structure, Tertiary / physiology
  • Proto-Oncogene Proteins c-mdm2 / genetics
  • Proto-Oncogene Proteins c-mdm2 / metabolism*
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*
  • Tumor Suppressor Proteins / genetics
  • Tumor Suppressor Proteins / metabolism*

Substances

  • Nuclear Proteins
  • Promyelocytic Leukemia Protein
  • Protein Isoforms
  • Transcription Factors
  • Tumor Suppressor Proteins
  • PML protein, human
  • Histone Acetyltransferases
  • KAT5 protein, human
  • Lysine Acetyltransferase 5
  • MDM2 protein, human
  • Proto-Oncogene Proteins c-mdm2