Impact of pathogenic missense mutations on the ARID domain of ARID1a

Clemson University, Clemson SC

Investigators

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Abstract

SUMMARY The AT-rich interacting domain-containing protein 1a (ARID1a), also named BAF250a, p270, or hOSA1, is a vital component of the Switch/Sucrose Non-Fermentable (SWI/SNF) chromatin remodeling complex. ARID1a, as part of the SWI/SNF complex, is responsible for crucial nuclear activities, including regulating transcription, DNA synthesis, DNA damage repair, and cell proliferation. Consequently, ARID1a is classified as a tumor suppressor gene and it is frequently mutated in solid tumor malignancies cancers, amounting to ~6% of every cancer and ~45% of all ovarian cancers. Loss of function mutations in ARID1a due to frameshift, stop-gain, or missense mutations leads to dysregulation of many gene pathways, including the prevention of tumor suppressor activities. Although the loss of function is evident in stop-gain and frameshift mutations, the impact of pathogenic missense mutations is subtler and more difficult to understand or predict. We hypothesize that pathogenic missense mutations impact the protein stability, DNA binding affinity, and structural dynamics, perturbing its function. Specifically, we seek to understand the effects of pathogenic missense mutations in the ARID domain of ARID1a, which is responsible for its direct interaction with DNA. Therefore, the broad goal of this research program is to understand the effects of pathogenic missense mutations in the ARID domain of ARID1a. The long-term implications of this program are the development of a unique framework that will pave the way for directly probing identified pathogenic missense mutations for future guided patient-specific screening therapeutic approaches. Our proposed study integrates biophysical studies, computational approaches, and single-molecule spectroscopy to characterize the stability, DNA binding, and structural dynamics of the ARID domain. Our studies will give insights into the correlation between missense pathogenic mutations and the structure-dynamics- function relationship. The PI and our research team are uniquely positioned to pursue the following specific aims: (1) to determine the impact of pathogenic missense mutations on the stability of the ARID domain; (2) to determine the impact of pathogenic missense mutations in the binding affinity of ARID domain to DNA; and (3) to determine the changes in the structure and dynamics of ARID domain as perturbed by pathogenic missense mutations. This interdisciplinary project will engage undergraduates in research to foster their interest and career development in both physical sciences and cancer research. The expected outcome will be a structural model of ARID1a’s ARID domain interaction with DNA, a library of pathogenic mutations ranked by the impact on stability and affinity, a system to improve pathogenic predictors, and the foundation for developing novel therapeutics and personalized medicine in the fight against cancer.