Open AccessRad53 limits CMG helicase uncoupling from DNA synthesis at replication forks
Author(s) -
Sujan Devbhandari,
Dirk Remus
Publication year - 2020
Publication title -
nature structural and molecular biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 9.448
H-Index - 270
eISSN - 1545-9993
pISSN - 1545-9985
DOI - 10.1038/s41594-020-0407-7
Subject(s) - replisome , helicase , control of chromosome duplication , dna replication , biology , dna polymerase , prokaryotic dna replication , microbiology and biotechnology , dnab helicase , primase , checkpoint kinase 2 , polymerase , eukaryotic dna replication , replication factor c , dna , genetics , protein kinase a , kinase , gene , protein serine threonine kinases , reverse transcriptase , rna
The coordination of DNA unwinding and synthesis at replication forks promotes efficient and faithful replication of chromosomal DNA. Disruption of the balance between helicase and polymerase activities during replication stress leads to fork progression defects and activation of the Rad53 checkpoint kinase, which is essential for the functional maintenance of stalled replication forks. The mechanism of Rad53-dependent fork stabilization is not known. Using reconstituted budding yeast replisomes, we show that mutational inactivation of the leading strand DNA polymerase, Pol ε, dNTP depletion, and chemical inhibition of DNA polymerases cause excessive DNA unwinding by the replicative DNA helicase, CMG, demonstrating that budding yeast replisomes lack intrinsic mechanisms that control helicase-polymerase coupling at the fork. Importantly, we find that the Rad53 kinase restricts excessive DNA unwinding at replication forks by limiting CMG helicase activity, suggesting a mechanism for fork stabilization by the replication checkpoint.