RT Journal Article
SR Electronic
T1 The non-catalytic role of DNA polymerase epsilon in replication initiation in human cells
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2022.03.21.485102
DO 10.1101/2022.03.21.485102
A1 Vipat, Sameera
A1 Gupta, Dipika
A1 Jonchhe, Sagun
A1 Anderspuk, Hele
A1 Rothenberg, Eli
A1 Moiseeva, Tatiana N.
YR 2022
UL http://biorxiv.org/content/early/2022/03/21/2022.03.21.485102.abstract
AB DNA polymerase epsilon in an essential enzyme, responsible for the synthesis of the leading strand during DNA replication. Deficiencies and mutations in DNA polymerase epsilon catalytic subunit (POLE1) cause severe developmental abnormalities and cancers. Paradoxically, the non-catalytic C-terminal domain of yeast polymerase epsilon catalytic subunit (Pol2) is sufficient for cell survival. The non-catalytic essential function of Pol2 in yeast has been associated with its role in the assembly of the replicative helicase CMG. However, the understanding of POLE1 functions in DNA replication initiation in human cells is falling behind. In this study we use an auxin-inducible degron system to study the effect of POLE1 depletion on replication initiation in human cells. Surprisingly, in the absence of POLE1, human cells were able to assemble CMG helicase and initiate DNA synthesis that failed shortly after. Expression of POLE1 C-terminal non-catalytic domain was enough to rescue replication initiation and support slow, but processive DNA synthesis, which was dependent on the POLE1-POLE2 interaction. We propose a model where in human cells POLE1/POLE2 are not essential for CMG assembly, but are required during later steps of replication initiation. Our study provides some insights into the role of DNA polymerase epsilon in replication initiation in human cells.Competing Interest StatementThe authors have declared no competing interest.