REU Summer Research

Research Project: The CST Complex Contributes to DNA Damage Repair

Presenter: Sophie Carrison

Faculty Mentor: Lata Balakrishnan

Project Description:

In life, aging is inevitable. The main factor that contributes to aging is that of telomere degradation on our chromosomes. Telomeres are portions of the chromosome that act as a protective structure, protecting the important coding parts of our DNA; the parts that make us who we are! In my research, I focused on the telomeric structure and studied the CST protein binding complex present on the telomere.

The CST complex is part of the Shelterin protein complex, containing the proteins CTC1, STN1, and TEN1, all directly interacting with the DNA strand. Sometimes, telomeric protein binding complexes may inhibit DNA damage repair pathways or DNA replication, making genetic mutations more prevalent and increasingly problematic. This does not seem to be the case for the CST complex as it is seen to stimulate the Base Excision Repair (BER) pathway. To study the relationship between CST and the BER pathway, the bulk of my experiments are using protein denaturing assays to see how the components of the CST complex affect BER pathway enzymes, such as APE1, DNA LIG1, and FEN1. The results indicate that the CST complex is able to stimulate those BER pathway enzymes, allowing the chromosome to maintain the stability of its protective telomere.