Functional uncoupling of MCM helicase and DNA polymerase activities activates the ATR-dependent checkpoint

Article Abstract:

Lesions induced by UV irradiation and cis-platinum cause the functional uncoupling of MCM helicase and DNA polymerase activities. Functional uncoupling of MCM helicase and DNA polymerase activities occurs in response to multiple forms of DNA damage and that there is general mechanism for generation of the checkpoint-activating signal following DNA damage.

DNA damage, Xenopus, DNA polymerases

Strength in numbers: Preventing rereplication via multiple mechanisms in eukaryotic cells

Article Abstract:

The diverse array of inhibitory pathways used by different organisms to prevent rereplication complex (pre-RC) assembly is reviewed. Findings suggest that eukaryotic cells regulate DNA replication through multiple mechanisms, all of which restrict access of the replicative DNA helicase to DNA from late G1 until the exit from mitosis.

Eukaryotes, Molecular genetics

Cdc7-Drf1 is a developmentally regulated protein kinase required for the initiation of vertebrate DNA replication

Article Abstract:

The study reports that in Xenopus egg extracts, Cdc7-Drf1 is far more abundant than Cdc7-Dbf4 and removal of Drf1 but not Dbf4 severely inhibits phosphorylation of Mcm4 and DNA replication. The results identify Drf1 as a developmentally regulated, essential activator of Cdc7 in Xenopus.

Vertebrates, Protein kinases