posted on 2024-02-28, 20:19authored byJun Wu, Jiabin Wu, Garrit Clabaugh, Yinsheng Wang
Alkyl phosphotriester (alkyl-PTE) lesions in DNA are
shown to be
poorly repaired; however, little is known about how these lesions
impact DNA replication in human cells. Here, we investigated how the SP and RP diastereomers
of four alkyl-PTE lesions (alkyl = Me, Et, nPr, or nBu) at the TT site perturb DNA replication in HEK293T cells.
We found that these lesions moderately impede DNA replication and
that their replicative bypass is accurate. Moreover, CRISPR-Cas9-mediated
depletion of Pol η or Pol ζ resulted in significantly
attenuated bypass efficiencies for both diastereomers of nPr- and nBu-PTE adducts, and the SP diastereomer of Et-PTE. Diminished bypass efficiencies
were also detected for the Rp diastereomer
of nPr- and nBu-PTE lesions upon
ablation of Pol κ. Together, our study uncovered the impact
of the alkyl-PTE lesions on DNA replication in human cells and revealed
the roles of individual translesion synthesis DNA polymerases in bypassing
these lesions.