The Structure of Telomerase RNA Attending Catalysis

University Of North Carolina At Chapel Hill, Chapel Hill NC

Investigators

Abstract

By replenishing the DNA at the 3' end of each chromosome, the enzyme telomerase is one key to cellular immortality. Functionally, telomerase is a remarkable nucleic acid polymerase that uses its integral RNA subunit as the template for the synthesis of the DNA located at the 3' end of eukaryotic chromosomes. The product of telomerase, telomeric DNA, is a single strand of highly repetitive G-rich DNA that is part of the specialized nucleoprotein complex called the telomere. Telomere maintenance is essential because the telomere guards the chromosome ends from mistaken recognition by the DNA repair machinery and consequent nucleolytic degradation. Several features of the catalytic mechanism of telomerase remain mysterious, and the research conducted in this project should illuminate the structural basis for telomerase function. Specifically, using Tetrahymena thermophila telomerase RNA (tTR) as a model, the investigator will elucidate the role of telomerase RNA through the use of a variety of high resolution biochemical techniques. In the first specific aim the structure of tTR will be studied both in solution and in the catalytically active complex using selective 2'-hydroxyl acylation analyzed by primer extension (SHAPE). In the second aim important functional groups throughout tTR will be identified using nucleotide analog interference mapping, a high throughput approach that allows simultaneous interrogation of functional groups of each nucleotide of an RNA. In the final aim, site-specific mutants of tTR, designed based on data from aims 1 and 2, will be used to corroborate those findings. This research will be conducted by students, including members of groups underrepresented in science. Furthermore, students who participate in a minority summer research program are expected to also participate in this project. Funding for the project will provide students with supplies and research stipends. Furthermore, telomerase is an important enzyme that affects many biological phenomena, including that of aging, and thus its understanding can benefit society in many ways.