SURF

Curtis Beck

Investigating the Functional Crosstalk Between the Crucial Epigenetic Silencers PRC1 and PRC2

In mammals, the Polycomb Repressive Complexes 1 and 2 (PRC1, PRC2) play crucial roles in maintaining gene expression patterns that enforce cell differentiation during embryonic development. Both complexes silence genes by post-translationally modifying the histone tails of nucleosomes, the smallest structural unit of chromatin. PRC1 plays a role in chromatin compaction by histone ubiquitination, whereas PRC2 reduces expression at the transcriptional level by histone methylation. The importance of these two complexes is emphasized by the fact that mutations in either complex results in embryonic lethality. While PRC1 and PRC2 are essential in maintaining cell identity, the molecular mechanism of PRC1-mediated chromatin compaction and the spreading of silencing marks by PRC2 remains poorly understood. Using cryo-electron microscopy and a novel technique to prevent the denaturation of sensitive protein complexes, we will directly image PRC2-nucleosome interactions to investigate the mechanisms underlying the recognition of specific histone ubiquitination by PRC2 and how it affects PRC2s methyltransferase activity. Our goal is to provide atomic-resolution structures of PRC1 and PRC2, providing insight into the crosstalk between two crucial gene-silencing enzymes.

Message to Sponsor

Thank you so much to the Rose Hills Foundation for providing me with this opportunity! SURF has been an incredible experience for me. Just over the course of a single summer, I gained much more confidence in my work than I had over the entire school year. Working full-time in my lab gave me the experience I needed in order to better exert my independence as a researcher, and this past summer has reaffirmed my plans to work in research as a career. Thank you!
  • Major: Molecular and Cell Biology
  • Sponsor: Rose Hills Experience
  • Mentor: Vignesh Kasinath