Creating A Cell-Free Assay To Assess The Binding Affinity Of Patient Variants In The BRCA1-PALB2 Interface

Abstract

BRCA1 and PALB2 are two important proteins necessary for DNA repair of double-stranded breaks via homologous recombination. Defects in this repair mechanism can lead to genomic instability and a higher rate of mutation acquisition, leading to an increased risk of breast and ovarian cancer. Patient variants of unknown significance (VUS) located in the BRCA1-PALB2 binding interface are currently being studied using in vivo biochemistry methods in order to measure a loss of function or using segregation analysis. Along with gaining structural insights into this binding interface using nuclear magnetic resonance (NMR), we have developed an in vitro, cell-free assay to study the BRCA1-PALB2 binding interface using isothermal titration calorimetry (ITC). This assay will be used in future Stewart Lab research to assess changes in binding affinity of patient variants.