We are delighted to share that Anna Karłowicz received a Best Poster Award at the 6th BIO Life Science Congress (BIO2025) in Poznań (17–20 September 2025). Her poster, entitled “Pol γB interacts with Pol β in human mitochondria under non-oxidative conditions and regulates its dRP lyase activity to facilitate short-patch DNA repair”, was recognised as one of the top contributions of the meeting.
The work presented in the poster sheds new light on the role of Pol γB, the accessory subunit of mitochondrial DNA polymerase γ, in regulating the activity of DNA polymerase β (Pol β). While Pol β has been previously implicated in mitochondrial base excision repair (BER), Anna’s study provided the first evidence that Pol γB directly interacts with Pol β under non-oxidative conditions and modulates its enzymatic function.
Functionally, Pol γB stabilises the Pol β-dRP Schiff base intermediate and reduces its strand displacement activity, without impairing one-nucleotide gap filling. Under oxidative stress, this interaction is abolished, leaving Pol β prone to DNA-protein crosslinks with oxidised abasic sites, which can be resolved by the mitochondrial nuclease EXOG in vitro.
Taken together, these findings reveal a previously unrecognised role of Pol γB in mitochondrial DNA repair, highlighting its ability to support short-patch BER under physiological conditions.
This award is a well-deserved recognition of Anna’s excellent work and dedication, and we warmly congratulate her on this achievement.
