p15(PAF), a novel PCNA associated factor with increased expression in tumor tissues

Oncogene. 2001 Jan 25;20(4):484-9. doi: 10.1038/sj.onc.1204113.


Proliferating cell nuclear antigen (PCNA) is an essential protein in both DNA replication and DNA damage repair. A novel 15 kD protein, p15(PAF), was identified as a PCNA-associated factor in a yeast two-hybrid screen using PCNA as the bait. p15(PAF) is localized primarily in the nucleus. p15(PAF) shares the conserved PCNA binding motif with several other PCNA binding proteins including CDK inhibitor p21. Overexpression of p15(PAF) competes with p21-PCNA binding. Mutation of this motif in p15(PAF) abolished its PCNA-binding activity. Notably, p15(PAF) expression in several types of tumor tissues was significantly increased, especially in esophageal tumors. Like PCNA, p15(PAF) may possess prognostic significance in a broad array of human cancers.

MeSH terms

  • Amino Acid Sequence
  • Binding, Competitive
  • Carrier Proteins / isolation & purification
  • Carrier Proteins / metabolism*
  • Cyclin-Dependent Kinase Inhibitor p21
  • Cyclins / metabolism
  • DNA-Binding Proteins
  • Female
  • Humans
  • Molecular Sequence Data
  • Proliferating Cell Nuclear Antigen / metabolism*
  • Protein Binding
  • RNA, Messenger / isolation & purification
  • RNA, Neoplasm / isolation & purification
  • Tissue Distribution
  • Two-Hybrid System Techniques


  • CDKN1A protein, human
  • Carrier Proteins
  • Cyclin-Dependent Kinase Inhibitor p21
  • Cyclins
  • DNA-Binding Proteins
  • PCLAF protein, human
  • Proliferating Cell Nuclear Antigen
  • RNA, Messenger
  • RNA, Neoplasm