1. Academic Validation
  2. Identification of the polypyrimidine tract binding protein-associated splicing factor.p54(nrb) complex as a candidate DNA double-strand break rejoining factor

Identification of the polypyrimidine tract binding protein-associated splicing factor.p54(nrb) complex as a candidate DNA double-strand break rejoining factor

  • J Biol Chem. 2005 Feb 18;280(7):5205-10. doi: 10.1074/jbc.M412758200.
Catherine L Bladen 1 Durga Udayakumar Yoshihiko Takeda William S Dynan
Affiliations

Affiliation

  • 1 Program in Gene Regulation and Cancer Biology, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA 30912, USA.
Abstract

The biological effects of ionizing radiation are attributable, in large part, to induction of DNA double-strand breaks. We report here the identification of a new protein factor that reconstitutes efficient double-strand break rejoining when it is added to a reaction containing the five other polypeptides known to participate in the human nonhomologous end-joining pathway. The factor is a stable heteromeric complex of polypyrimidine tract-binding protein-associated splicing factor (PSF) and a 54-kDa nuclear RNA-binding protein (p54(nrb)). These polypeptides, to which a variety of functions have previously been attributed, share extensive homology, including tandem RNA recognition motif domains. The PSF.p54(nrb) complex cooperates with Ku protein to form a functional preligation complex with substrate DNA. Based on structural comparison with related proteins, we propose a model where the four RNA recognition motif domains in the heteromeric PSF.p54(nrb) complex cooperate to align separate DNA molecules.

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