Center on the Biology of Aging

Mary Tarantino is a student in the lab of Professor Sarah Delaney. Her project is focused on the initiation of base excision repair in the nucleosome core particle by the UDG superfamily glycosylases uracil DNA glycosylase (UDG), single strand-selective monofunctional uracil DNA glycosylase (SMUG1), and thymine DNA glycosylase (TDG). Mary has found that though UDG, SMUG1, and TDG readily excise uracil from DNA duplex substrates, these three glycosylases show significant variation in their repair of uracil lesions in DNA packaged into the nucleosome core particle. Namely, UDG showed activity comparable to duplex, while SMUG1 was almost completely inhibited, and TDG exhibited intermediate levels of inhibition. Given that these three enzymes have overlapping substrates, she is now investigating ways in which their activities may be regulated, such as by post-translational modification. She matriculated in the MCB Program in September 2017, and is currently in her seventh year of the M.D./Ph.D. program and her fifth year in the MCB Graduate Program. She was supported by this T32 from 09/01/18 to 08/31/19). She is currently supported by an NRSA F30 fellowship which started 09/01/19. Her work has already contributed to three published papers, and two more are in preparation.