Molecular Recognition in Biological Systems and Bioinformatics

Real-time images of GFP-tagged RPA being recruited to sites of DNA damage in vivo.

Mechanisms of DNA replication; DNA damage regulation of DNA replication; Papillomavirus; Enzymology; Biochemistry.

Our laboratory is interested in the mechanisms and DNA damage regulation of human and viral DNA replication. We use a combination of biochemical, genetic, and pharmacological approaches to study these areas.

A major area of research in our group is how the SV40 and papillomavirus DNA replication proteins pirate the cellular DNA replication apparatus to replicate their viral DNA. Some of our recent work has focused on how the papillomavirus replication proteins, E1 and E2, interact with and modulate the function of cellular replication proteins including: the cellular ssDNA binding complex RPA, DNA topoisomerase, and DNA polymerases. In addition to helping us understand basic mechanisms of how DNA synthesis proteins interact with one another to carry out their functions, these studies may provide novel avenues to explore for possible anti-papillomavirus therapeutic approaches.

We also are interested in how these viral replication systems, as well as their host cells, are regulated in response to DNA damage. Multiple pathways are activated to prevent DNA replication once cells detect DNA damage, and we have begun to elucidate some of these pathways. We are currently studying the activation of the DNA damage kinase, ATR, and how it targets the DNA replication machinery. ATR is a very important area of research, as attenuation of ATR function is considered a promising target for anti-cancer therapeutics.

More recently we have begun working on DNA Mismatch Repair, a pathway whose loss plays an important role in how many cancers arise. Specifically, we have begun to study how this pathway, also known as post-replicative repair, is targeted to newly replicated DNA. We have shown that at least for viral DNA replication, this recruitment primarily occurs through interactions with the cellular replication sliding-clamp protein, PCNA.

• Human
• Papillomaviruses
• Simian virus 40

• Replication Protein A
• Topoisomerase I
• DNA polymerase delta
• Proliferating Cell Nuclear Antigen
• PV E1 and E2 proteins
• SV40 large Tumour Antigen

HPV infections; both sexually transmitted and common warts; Cancers of many types especially, but not limited to: cervical, other anogenital, and oropharyngeal.

• Protein purification
• Various enzyme assays such as: DNA polymerase, DNA helicase, protein kinase, topoisomerase, DNA binding, protein-protein interaction, etc.
• Immunocytology and immunoblotting

DAPI

• HeLa
• 293
• Various deficient lines including: ATM, Seckel, others

HPV infection and most cancers

Epidermis

http://www.smbs.buffalo.edu/wcmpi/faculty/melendy.html