We are interested in understanding how cells maintain genomic stability. One of the mechanisms that regulates this critical process is defective in Fanconi anemia (FA), a genetic model for human susceptibility to cancer. The FA pathway is at the crossroads of DNA replication, the DNA damage response, and the repair of damage resulting from DNA crosslinkers commonly used in effective anti-cancer therapies. Because the majority of the FA proteins are novel, unraveling the functional role of the FA pathway proteins in these fundamental processes is an enduring challenge.
Our lab pioneered the use of cell-free assays for FA proteins in extracts from Xenopus eggs. These extracts allow analysis of FA protein function and post-translational modifications in a context that is permissive for naturally-regulated DNA synthesis. The recruitment of Fanconi proteins to chromatin in S-phase is providing us with a biochemical platform for elucidating the molecular function of the Fanconi proteins during in full context with DNA replication and the DNA damage response.
Our current projects:
Biochemical analysis of FA protein complexes. We are using biochemical assays in Xenopus cell–free extracts together with assays in human cells to identify functionally important proteins and protein complexes in the FA network.
The role of the FA proteins at early stages of hematopoiesis. We identified a novel transcriptional repressor (FAZF, for Fanconi Anemia Zinc Finger) that binds to FANCC, one of the Fanconi proteins. We are interested in the functional consequences of this interaction in normal and dysregulated hematopoiesis.
Chemical Modulation of the FA/BRCA Pathway. We designed a rapid, inexpensive and sensitive cell-free assay to screen for small molecules that modulate the FA/BRCA pathway. We are using this assay to identify potential therapeutic targets and to dissect the activity of the FA proteins within the network of proteins that guard genomic stability.
Deconstructing the FA/BRCA pathway. What triggers activation of the FA/BRCA pathway proteins is not understood. We are testing DNA binding and DNA structure-specific FA protein activation in cell free extracts to identify the FA-specific transactions.
Our long-term goal is to reverse engineer the FA pathway to gain understanding that we hope will lead to new approaches for targeted drug design in Fanconi anemia, as well as for cancer prevention and treatment.