Nucleotides make up ribonucleic acids (RNAs) and contain the crucial "blueprint" of genetic information that is used by cells to make proteins. With this award, the Chemistry of Life Processes Program in the Division of Chemistry is funding Dr. Jia Sheng, from the State University of New York at Albany, to develop tools to incorporate modified nucleotides into RNA with high precision. These modifications change the RNA structure and function. These changes help us understand the role of RNA in numerous biological processes. The research focuses on the determining the three-dimensional structure of RNAs containing the modified nucleotides, understanding how these changes affect the reactivity of the RNA and then studying the study of the nucleotides' role in gene expression. The Dr. Sheng makes the new natural nucleotides and their 3D structures available to a wide range of researchers. The strategies developed under this project may be applicable to other enzymes targeting different RNA modifications, leading to a new general approach for RNA editing and thus, this research is considered to be within the Understanding the Rules of Life initiative. The research methodologies and outcomes of the study are integrated into a new course "Nucleic Acid Chemistry". Dr. Sheng is a leader in the "World of Chemistry" program which helps freshmen chemistry majors transition to college successfully. Dr. Sheng also organizes the annual "RNA Day" in his lab for local K-12 students offering experimental demonstrations and presentations to awaken their inner scientist. Finally, the research group recruits students and teachers to participate in summer research through the "University in the High School" program.
The research studies made possible by this award focus on the relatively new epigenetic significance of chemically-modified cytosines in RNA. Synthetic 5-methylcytosine (5mC) and its oxidized variants (5xrC) are systematically incorporated into RNAs to determine their impact on the stability and local and global conformations of the RNAs. In addition, studies with 5xrC-modified RNAs reveal their effects on enzyme recognition and the mechanism of enzymatic oxidation of 5mC by the ten-eleven translocation (TET) family of oxygenases. Finally, the sequence targeting the clustered regularly interspaced short palindromic repeats (CRISPR) enzyme is fused with a TET oxygenase to create a tool that site-selectively oxidizes 5mC in natural RNAs. This tool is used to determine how 5xrC nucleotides affect the efficiency of translating cellular mRNAs into proteins. The knowledge gained and new general approaches developed by Dr. Sheng may benefit other scientists who study epitranscriptomic modifications of messenger RNA and posttranscriptional regulation of gene expression in eukaryotes.
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.
