Virginia A. Zakian

Zakian discovered universal features of telomeres, including telomeric silencing, and the replication­dependent formation of the G-rich telomeric 3' overhang. Zakian has also contributed to our understanding of how replication forks negotiate natural barriers. She discovered that the highly conserved Pif1 helicase is critical for replication fork progression and acts to eject telomerase from telomeres and double strand breaks, thereby preventing telomerase action at random sites of damage. She showed that Pif1 family helicases have more general roles in combatting the replication stress that arises at naturally occurring replication barriers, such as protein complexes, converged replication forks, and G-quadruplex DNA structures.