Molecular analysis of the function of BRCA1-TONSL complexes

Summary

Principal Investigator: SARAH JAMES HILL
Abstract: DESCRIPTION (provided by applicant): BRCA1 (B1) is a breast and ovarian tumor suppressor. Its best known function is in the repair of double strand breaks (DSB) by homologous recombination (HR). It can also function in other types of DNA damage repair (cf below), as well as in DNA damage checkpoints. However, there is limited in depth knowledge about any of the purported functions for B1or how it acts as a tumor suppressor. To address this problem, we purified B1-containing protein complexes from a human cell line and analyzed the complexes by mass spectrometry (MS). Our hope was that by better defining the B1 protein partner repertoire we might be able to better understand known B1 functions or potentially hypothesize new B1 functions based on the known functions of identified interactors. In this analysis, we repeatedly identified a protein called TONSL (aka NFKBIL2) as a B1 interactor. This protein has been suggested to function in the repair of collapsed replication forks. Recently, our group has shown that B1 functions in the repair of stalled replication forks. Given the similar suggested function for both proteins, and based on our preliminary analysis of the B1-TONSL interaction, we hypothesize that B1 recruits TONSL to collapsed replication forks to aid in the repair of DSB breaks arising at these sites. The four specific aims of this proposal wil focus on this hypothesis. The goal of specific aim 1 will be to perform a structure function analysis on the B1-TONSL interaction as a means of assessing, genetically, the hypothesis that B1 recruits TONSL to collapsed forks and that the B1- TONSL complex is involved in repair of these structures. The goal of aim 2 will be to understand an observation from our preliminary data. We find that after UV damage, B1 localizes at UV damage sites in virtually all S/G2 cells. However, TONSL co-localizes with B1 at these sites in only some of these cells. The goal of aim 2 is to determine why this is the case, which could shed light on how B1-TONSL complexes function. The goal of aim 3 is to search for and, if feasible, identify other members of the B1-TONSL subcomplex, by affinity purification and MS. By doing this we hope to identify subunits with known biochemical functions and then assess the contributions of these properties to B1-TONSL function and vice versa. This approach could further illuminate aspects of the function of this complex at collapsed forks and/or suggest new hypotheses for the function of this complex. The goal of aim 4 is to determine, with help from collaborators, whether TONSL and/or any other member of the B1-TONSL complex is a product of a breast cancer suppressor gene by searching for relevant mutations in whole genome sequence libraries of breast tumors. This work will be supervised by the candidate's sponsor in a program composed of laboratory-based research training leavened by attendance at relevant scientific meetings. Ideally, success in this effort will contribute to a better understanding of B1 function and how loss of B1 function leads to breast and/or ovarian cancer.
Funding Period: 2012-04-01 - 2016-03-31
more information: NIH RePORT

Research Grants

  1. Mechanisms of Esophageal Carcinogenesis
    Anil K Rustgi; Fiscal Year: 2013
  2. Wisconsin Center of Excellence in Genomics Science
    Michael Olivier; Fiscal Year: 2013
  3. The Virtual Physiological Rat Project
    Daniel A Beard; Fiscal Year: 2013
  4. Seattle Cancer Consortium Breast SPORE
    Peggy L Porter; Fiscal Year: 2013
  5. University of Maryland Greenebaum Cancer Center Support Grant
    Kevin J Cullen; Fiscal Year: 2013
  6. SPORE IN GASTROINTESTINAL CANCER
    Scott E Kern; Fiscal Year: 2013
  7. The Role of 53BP1 Interacting Proteins in Regulation of DNA Repair Choice
    JINESH SHAILESH GHEEYA; Fiscal Year: 2013
  8. Novel triplex-engineered, BRCA1-mutated cell lines for research
    Peter M Glazer; Fiscal Year: 2013
  9. DEGENERATIVE AND DEMENTING DISEASES OF AGING
    Stanley B Prusiner; Fiscal Year: 2013
  10. Center for Neuroplasticity at the University of Puerto Rico
    Steven N Treistman; Fiscal Year: 2013

Detail Information

Research Grants30

  1. Mechanisms of Esophageal Carcinogenesis
    Anil K Rustgi; Fiscal Year: 2013
    ..abstract_text> ..
  2. Wisconsin Center of Excellence in Genomics Science
    Michael Olivier; Fiscal Year: 2013
    ..Data, technology, and software will be widely disseminated by multiple mechanisms including licensing and commercialization activities. ..
  3. The Virtual Physiological Rat Project
    Daniel A Beard; Fiscal Year: 2013
    ..This proposal targets the grand challenge of understanding complex multi-faceted disease phenotypes through experiments and simulations that capture the complex genotype-environment-phenotype relationship. ..
  4. Seattle Cancer Consortium Breast SPORE
    Peggy L Porter; Fiscal Year: 2013
    ..abstract_text> ..
  5. University of Maryland Greenebaum Cancer Center Support Grant
    Kevin J Cullen; Fiscal Year: 2013
    ..Reflecting our remarkable and continued growth, UMGCC seeks to renew its CCSG to enhance and expand its efforts in high-quality and clinically relevant cancer research. ..
  6. SPORE IN GASTROINTESTINAL CANCER
    Scott E Kern; Fiscal Year: 2013
    ..Alison Klein. The Career Development Program (Dr. Scott Kern) aids the emergence of new investigators and the Research Developmental Program (Dr. Bert Vogelstein) provides rapid funding of innovative directions. ..
  7. The Role of 53BP1 Interacting Proteins in Regulation of DNA Repair Choice
    JINESH SHAILESH GHEEYA; Fiscal Year: 2013
    ..This will lead to new understanding of how DNA repair pathways are regulated as well as innovative approaches to target chemo resistance in human cancers. ..
  8. Novel triplex-engineered, BRCA1-mutated cell lines for research
    Peter M Glazer; Fiscal Year: 2013
    ..We will characterize these cells for key aspects of BRCA1 function, including regulation of transcription and of DNA damage responses and DNA repair. ..
  9. DEGENERATIVE AND DEMENTING DISEASES OF AGING
    Stanley B Prusiner; Fiscal Year: 2013
    ..The ultimate goal of all the proposed studies is to define the molecular events that feature in the formation of human prions in order to develop therapeutics that cure the human prion diseases. ..
  10. Center for Neuroplasticity at the University of Puerto Rico
    Steven N Treistman; Fiscal Year: 2013
    ..This UPR COBRE Center should define pathways and benchmarks for basic and translational research across the UPR system for the next decades. ..
  11. ANALYSIS OF BRCA1 RECOMBINATION FUNCTIONS
    Ralph Scully; Fiscal Year: 2013
    ..In this proposal, we will conduct experiments to find out whether BRCA1's tumor suppressor function is linked to its ability to repair broken DNA by sister chromatid recombination. ..
  12. MECHANISMS OF BREAST DEVELOPMENT AND CARCINOGENESIS
    Robert A Weinberg; Fiscal Year: 2013
    ..abstract_text> ..
  13. Spatial and Temporal Regulation of Angiogenesis
    HAROLD FISHER DVORAK; Fiscal Year: 2013
    ..abstract_text> ..
  14. UNMC EPPLEY CANCER CENTER SUPPORT GRANT
    Kenneth H Cowan; Fiscal Year: 2013
    ....
  15. Cellular and Molecular Tumorsuppressor Processes Uncovered by DNA Fork Protection
    Katharina Schlacher; Fiscal Year: 2013
    ..Dr. Schlacher and her mentors thus view this project as a critical enabling opportunity for her to meet the challenges of her research goals and aspirations. ..
  16. SPORE in Soft Tissue Sarcoma
    Samuel Singer; Fiscal Year: 2013
    ..abstract_text> ..