DSS1 and ssDNA regulate oligomerization of BRCA2

Hang Phuong Le, Xiaoyan Ma, Jorge Vaquero, Megan Brinkmeyer, Fei Guo, Wolf-Dietrich Heyer, Jie Liu

Research output: Contribution to journalArticle

Abstract

The tumor suppressor BRCA2 plays a key role in initiating homologous recombination by facilitating RAD51 filament formation on single-stranded DNA. The small acidic protein DSS1 is a crucial partner to BRCA2 in this process. In vitro and in cells (1,2), BRCA2 associates into oligomeric complexes besides also existing as monomers. A dimeric structure was further characterized by electron microscopic analysis (3), but the functional significance of the different BRCA2 assemblies remains to be determined. Here, we used biochemistry and electron microscopic imaging to demonstrate that the multimerization of BRCA2 is counteracted by DSS1 and ssDNA. When validating the findings, we identified three self-interacting regions and two types of self-association, the N-to-C terminal and the N-to-N terminal interactions. The N-to-C terminal self-interaction of BRCA2 is sensitive to DSS1 and ssDNA. The N-to-N terminal self-interaction is modulated by ssDNA. Our results define a novel role of DSS1 to regulate BRCA2 in an RPA-independent fashion. Since DSS1 is required for BRCA2 function in recombination, we speculate that the monomeric and oligomeric forms of BRCA2 might be active for different cellular events in recombinational DNA repair and replication fork stabilization.

Original languageEnglish (US)
Pages (from-to)7818-7833
Number of pages16
JournalNucleic acids research
Volume48
Issue number14
DOIs
StatePublished - Aug 20 2020

ASJC Scopus subject areas

  • Genetics

Fingerprint Dive into the research topics of 'DSS1 and ssDNA regulate oligomerization of BRCA2'. Together they form a unique fingerprint.

  • Cite this

    Le, H. P., Ma, X., Vaquero, J., Brinkmeyer, M., Guo, F., Heyer, W-D., & Liu, J. (2020). DSS1 and ssDNA regulate oligomerization of BRCA2. Nucleic acids research, 48(14), 7818-7833. https://doi.org/10.1093/nar/gkaa555