George-Lucian Moldovan, PhD

Dr. George-Lucian Moldovan’s major research goal is to elucidate the molecular mechanism of replication of DNA lesions in human cells, using an integrative approach that includes:

• identification of the factors involved in detection and processing of stalled forks;
• biochemical reconstitution of discrete steps of the fork restart process; and
• genetic analyses to assess the role of these processes in genomic stability, cellular transformation, and cancer prevention and therapy.

For all organisms, the information necessary for living and propagation is encoded in their genomes. Maintaining and transferring stable genomes to the progeny is thus essential. In humans, failure to preserve the correct DNA sequence can result in cellular transformation and cancer, as well as degeneration and accelerated aging. To avoid genomic instability, cells employ numerous mechanisms that detect, signal and repair DNA lesions. These mechanisms also stabilize and protect complex macromolecular structures such as replication forks (which form during DNA duplication) and ensure the correct and timely replication and segregation of chromosomes. They are subjected to complex cellular regulation and are frequently inactivated in cancer.

In particular, DNA replication is a complex process that requires tight regulation to ensure genomic stability. Replication of damaged DNA poses a great risk, since DNA lesions cannot be processed by regular replicative polymerases and thus result in stalling of the replication machinery. Understanding how the replication machinery deals with roadblocks is fundamental, since prolonged replication stalling can result in strand breaks, translocations, and genomic instability. What ultimately dictates the fate of stalled forks is not understood and in fact remains one of the biggest unsolved mysteries in cell biology.

To resolve this conundrum, the missing components of this regulatory circuit must be identified and characterized.