RNF144A, an E3 ubiquitin ligase for DNA-PKcs, promotes apoptosis during DNA damage

Proc Natl Acad Sci U S A. 2014 Jul 1;111(26):E2646-55. doi: 10.1073/pnas.1323107111. Epub 2014 Jun 16.


Several ring between ring fingers (RBR) -domain proteins, such as Parkin and Parc, have been shown to be E3 ligases involved in important biological processes. Here, we identify a poorly characterized RBR protein, Ring Finger protein 144A (RNF144A), as the first, to our knowledge, mammalian E3 ubiquitin ligase for DNA-PKcs. We show that DNA damage induces RNF144A expression in a p53-dependent manner. RNF144A is mainly localized in the cytoplasmic vesicles and plasma membrane and interacts with cytoplasmic DNA-dependent protein kinase, catalytic subunit (DNA-PKcs). DNA-PKcs plays a critical role in the nonhomologous end-joining DNA repair pathway and provides prosurvival signaling during DNA damage. We show that RNF144A induces ubiquitination of DNA-PKcs in vitro and in vivo and promotes its degradation. Depletion of RNF144A leads to an increased level of DNA-PKcs and resistance to DNA damaging agents, which is reversed by a DNA-PK inhibitor. Taken together, our data suggest that RNF144A may be involved in p53-mediated apoptosis through down-regulation of DNA-PKcs when cells suffer from persistent or severe DNA damage insults.

Keywords: DDR; endosome; transmembrane domain.

Publication types

  • Research Support, American Recovery and Reinvestment Act
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Apoptosis / physiology*
  • Blotting, Western
  • Carrier Proteins / metabolism
  • Carrier Proteins / physiology*
  • Catalytic Domain / physiology*
  • Colony-Forming Units Assay
  • DNA Damage / physiology*
  • DNA Primers / genetics
  • DNA-Activated Protein Kinase / metabolism
  • DNA-Activated Protein Kinase / physiology*
  • Fluorescent Antibody Technique
  • Gene Expression Regulation, Enzymologic / physiology*
  • HEK293 Cells
  • Humans
  • Immunoprecipitation
  • Real-Time Polymerase Chain Reaction
  • Reverse Transcriptase Polymerase Chain Reaction
  • Ubiquitin-Protein Ligases / metabolism
  • Ubiquitin-Protein Ligases / physiology*


  • Carrier Proteins
  • DNA Primers
  • RNF144A protein, human
  • Ubiquitin-Protein Ligases
  • DNA-Activated Protein Kinase