The genetic and biochemical basis of human leading strand synthesis.

ABSTRACT: The maintenance of genome stability requires efficient leading strand synthesis by DNA Polymerase Epsilon (Polε). By performing CRISPR genetic screens in cells lacking the POLE4 subunit of Polε we define a genetic map of the factors required to support Polε function in the absence of its accessory subunits. A set of genes involved in iron metabolism emerge as required to sustain Iron Sulphur Cluster (ISC)-dependent Polε activity. We then dissect a synthetic lethal interaction between POLE3-POLE4 and the CHTF18-RFC2/5 complex. By combining cell biology, structural modelling and biochemistry, we define the existence of two tiers of regulation of Polε processivity: leading strand-specific loading of PCNA by CHTF18-RFC2/5 and "gripping" of newly synthesised dsDNA by POLE3-POLE4. The combined l

SUBMITTER: Agnarelli A 

PROVIDER: S-EPMC12796321 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature