SPOP promotes transcriptional expression of DNA repair and replication factors to prevent replication stress and genomic instability

Nucleic Acids Res. 2018 Oct 12;46(18):9484-9495. doi: 10.1093/nar/gky719.

Abstract

Mutations in SPOP, the gene most frequently point-mutated in primary prostate cancer, are associated with a high degree of genomic instability and deficiency in homologous recombination repair of DNA but the underlying mechanisms behind this defect are currently unknown. Here we demonstrate that SPOP knockdown leads to spontaneous replication stress and impaired recovery from replication fork stalling. We show that this is associated with reduced expression of several key DNA repair and replication factors including BRCA2, ATR, CHK1 and RAD51. Consequently, SPOP knockdown impairs RAD51 foci formation and activation of CHK1 in response to replication stress and compromises recovery from replication fork stalling. An SPOP interactome analysis shows that wild type (WT) SPOP but not mutant SPOP associates with multiple proteins involved in transcription, mRNA splicing and export. Consistent with the association of SPOP with transcription, splicing and RNA export complexes, the decreased expression of BRCA2, ATR, CHK1 and RAD51 occurs at the level of transcription.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Ataxia Telangiectasia Mutated Proteins / genetics
  • BRCA2 Protein / genetics
  • Cell Line, Tumor
  • Checkpoint Kinase 1 / genetics
  • DNA Breaks, Double-Stranded
  • DNA Damage / genetics
  • DNA Repair / genetics
  • DNA Replication / genetics*
  • Gene Expression Regulation / genetics
  • Gene Knockdown Techniques
  • Genomic Instability / genetics*
  • Humans
  • Male
  • Mutation
  • Nuclear Proteins / genetics*
  • Prostatic Neoplasms / genetics*
  • Prostatic Neoplasms / pathology
  • RNA Splicing / genetics
  • RNA, Messenger / genetics
  • Rad51 Recombinase / genetics
  • Repressor Proteins / genetics*

Substances

  • BRCA2 Protein
  • BRCA2 protein, human
  • Nuclear Proteins
  • RNA, Messenger
  • Repressor Proteins
  • SPOP protein, human
  • ATR protein, human
  • Ataxia Telangiectasia Mutated Proteins
  • CHEK1 protein, human
  • Checkpoint Kinase 1
  • Rad51 Recombinase