Comprehensive analysis of missense variations in the BRCT domain of BRCA1 by structural and functional assays.

Abstract

Genetic screening of the breast and ovarian cancer susceptibility gene BRCA1 has uncovered a large number of variants of uncertain clinical significance. Here, we use biochemical and cell-based transcriptional assays to assess the structural and functional defects associated with a large set of 117 distinct BRCA1 missense variants within the essential BRCT domain of the BRCA1 protein that have been documented in individuals with a family history of breast or ovarian cancer. In the first method, we used limited proteolysis to assess the protein folding stability of each of the mutants compared with the wild-type. In the second method, we used a phosphopeptide pull-down assay to assess the ability of each of the variants to specifically interact with a peptide containing a pSer-X-X-Phe motif, a known functional target of the BRCA1 BRCT domain. Finally, we used transcriptional assays to assess the ability of each BRCT variant to act as a transcriptional activation domain in human cells. Through a correlation of the assay results with available family history and clinical data, we define limits to predict the disease risk associated with each variant. Forty-two of the variants show little effect on function and are likely to represent variants with little or no clinical significance; 50 display a clear functional effect and are likely to represent pathogenic variants; and the remaining 25 variants display intermediate activities. The excellent agreement between the structure/function effects of these mutations and available clinical data supports the notion that functional and structure information can be useful in the development of models to assess cancer risk.

• Authors: Megan S Lee, Ruth Green, Sylvia M Marsillac, Nicolas Coquelle, R Scott Williams, Telford Yeung, Desmond Foo, D Duong Hau, Ben Hui, Alvaro N A Monteiro, J N Mark Glover
• Journal: Cancer research (Cancer Res) Vol. 70 Issue 12 Pg. 4880-90 (Jun 15 2010) ISSN: 1538-7445 [Electronic] United States
• PMID: 20516115 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• BRCA1 Protein
• Phosphopeptides

Topics

• BRCA1 Protein (chemistry, genetics, metabolism)
• Breast Neoplasms (genetics, metabolism, pathology)
• Female
• Genetic Variation (genetics)
• Humans
• Mutation, Missense (genetics)
• Phosphopeptides (metabolism)
• Protein Folding
• Protein Structure, Tertiary
• Transcription, Genetic
• Transcriptional Activation