p73 is regulated by tyrosine kinase c-Abl in the apoptotic response to DNA damage

Nature. 1999 Jun 24;399(6738):814-7. doi: 10.1038/21704.


The protein p73 is a structural and functional homologue of the p53 tumour-suppressor protein but, unlike p53, it is not induced in response to DNA damage. The tyrosine kinase c-Abl is activated by certain DNA-damaging agents and contributes to the induction of programmed cell death (apoptosis) by p53-dependent and p53-independent mechanisms. Here we show that c-Abl binds to p73 in cells, interacting through its SH3 domain with the carboxy-terminal homo-oligomerization domain of p73. c-Abl phosphorylates p73 on a tyrosine residue at position 99 both in vitro and in cells that have been exposed to ionizing radiation. Our results show that c-Abl stimulates p73-mediated transactivation and apoptosis. This regulation of p73 by c-Abl in response to DNA damage is also demonstrated by a failure of ionizing-radiation-induced apoptosis after disruption of the c-Abl-p73 interaction. These findings show that p73 is regulated by a c-Abl-dependent mechanism and that p73 participates in the apoptotic response to DNA damage.

MeSH terms

  • Animals
  • Apoptosis*
  • Binding Sites
  • COS Cells
  • Cell Line
  • DNA Damage*
  • DNA-Binding Proteins / metabolism*
  • Genes, Tumor Suppressor
  • Mice
  • Nuclear Proteins / metabolism*
  • Phosphorylation
  • Protein Binding
  • Proto-Oncogene Proteins c-abl / metabolism*
  • Recombinant Proteins / metabolism
  • Tumor Protein p73
  • Tumor Suppressor Proteins
  • src Homology Domains


  • DNA-Binding Proteins
  • Nuclear Proteins
  • Recombinant Proteins
  • Trp73 protein, mouse
  • Tumor Protein p73
  • Tumor Suppressor Proteins
  • Proto-Oncogene Proteins c-abl