BRCA1-BRCT Mutations Alter the Subcellular Localization of BRCA1 In Vitro

Anticancer Res. 2021 Jun;41(6):2953-2962. doi: 10.21873/anticanres.15077.

Abstract

Background/aim: Numerous missense mutations have been determined in the BRCT domain of the BRCA1 gene, affecting localization and interaction of BRCA1 with other proteins.

Materials and methods: We examined whether the M1775K and V1809F mutations in the BRCT domain affect BRCA1 cellular localization. Cells were transfected with pEGFP-C3-BRCA1 and detected by fluorescence microscopy.

Results: Following induction of DNA damage, cytoplasmic mislocalization was observed for both M1775K and V1809F mutants compared to EGFP-BRCA1wt and the less common variant M1652I. These results indicate that M1775K and V1809F mutations may change the function of the protein by affecting BRCA1 localization.

Conclusion: There is a correlation between subcellular localization of BRCA1 and diminished DNA repair observed in breast cancer cells, which may be explained by structural variations and altered binding properties of phosphopeptides.

Keywords: BRCA1; BRCT; cellular localization; mutants.

MeSH terms

  • BRCA1 Protein / chemistry
  • BRCA1 Protein / metabolism*
  • DNA Damage
  • DNA Repair
  • Genes, BRCA1*
  • Green Fluorescent Proteins / genetics
  • Humans
  • MCF-7 Cells
  • Microscopy, Fluorescence
  • Mutation, Missense*
  • Protein Domains
  • Subcellular Fractions / metabolism*

Substances

  • BRCA1 Protein
  • BRCA1 protein, human
  • enhanced green fluorescent protein
  • Green Fluorescent Proteins