CAREER: Functional Dissection of Ubiquitination Signaling by Quantitative Chemical Proteomics

With this award, the Chemistry of Life Processes Program in the Chemistry Division is funding Dr. Yue Chen from the University of Minnesota to investigate a specific cellular signaling pathway using an innovative new methodology called, quanititative chemical proteomics. Ubiquitination is a modification of proteins with a number of biological functions including signaling. For example, when DNA is damaged, ubiquitination plays a critical role in activating specific response pathways to initiate DNA damage repair. A newly developed quantitative chemical proteomics approach is applied to reveal just how this takes place. Experimental studies are expected to identify novel ubiquitination-dependent regulatory mechanisms and find previously unknown enzymatic activities in DNA damage response. During the project, undergraduate biochemistry students train with interdisciplinary techniques in chemical synthesis and quantitative proteomics through a fully integrated chemical proteomic training program. Additional outreach programs promote biochemistry education for high school students through specifically designed field learning activities.

The research projects integrate the new isotope-encoded stoichiometry analysis method and chemical proteomics strategies to functionally dissect ubiquitination signaling pathways. Compared to the traditional relative quantification, this approach enables site-specific absolute quantification of ubiquitination prevalence and, therefore, allows the identification of ubiquitination targets that are stoichiometrically activated in specific biological processes. This strategy is applied to determine the dynamic activation of ubiquitination signaling during DNA double-strand break. Temporal dynamics analysis and functional validation reveal key regulatory ubiquitination targets that are critical for the activation of specific response pathways. In vitro and in vivo quantitative analysis determine the substrate dynamics and specificities of important ubiquitination E3 ligases in double-strand break and repair. Overall, these studies provide mechanistic insights into the ubiquitination-mediated signaling and regulatory pathways in DNA damage and response.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.