DNA replication is a complex and perilous undertaking for cells because the risk of damage is greatest when the double helix is unwound for copying. Adding to this complexity is the fact that some DNA sequences tend to be more difficult to replicate accurately than others. Notable among these natural barriers to faithful replication are sequence motifs that adopt non-canonical structures such as G-quadruplex (G4) DNA. Failure to maintain evolutionarily conserved G4 motifs leads to genetic and epigenetic instability that is associated with chromosomal damage, cellular dysfunction, neurological diseases, and cancer. While it is known that special processing is required to maintain G4 integrity, the precise molecular mechanisms and cellular responses involved remain important areas of research. This project will investigate the role of a polymerase called Rev1 in copying and repairing G4 DNA. Successful completion of the project will provide new knowledge on the bypass of such replication barriers, a fundamental requirement for all living systems. The project will also support graduate student training at the University of Arkansas for Medical Sciences (UAMS), undergraduate trainees at Hendrix College, and mentoring of high-school students in Arkansas through outreach programs housed at UAMS.
The major goal of the project is to test the hypothesis that Rev1, an enzyme with an unusual mechanism of action, functions to disrupt G4 structures, recruit other enzymes to sites of G4-induced replication stress, and maintain genetic/epigenetic integrity during replication of G4 motifs. The research will employ biophysical and biochemical approaches, including transient kinetics and proteomics, as well as cell-based assays to study key aspects of Rev1 activity that likely facilitate G4 replication and maintenance of the surrounding chromatin landscape. The outcomes will improve models of DNA replication and provide mechanistic insights into DNA processing pathways that have evolved to maintain important structural features of eukaryotic genomes.
This project is jointly funded by the Molecular and Cellular Biosciences Division and the Established Program to Stimulate Competitive Research (EPSCoR).
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.
