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Replisome disassembly is the final step of eukaryotic DNA replication and is triggered by ubiquitylation of the CDC45-MCM-GINS (CMG) replicative helicase.sup.1-3. Despite being driven by evolutionarily diverse E3 ubiquitin ligases in different eukaryotes (SCF.sup.Dia2 in budding yeast.sup.1, CUL2.sup.LRR1 in metazoa.sup.4-7), replisome disassembly is governed by a common regulatory principle, in which ubiquitylation of CMG is suppressed before replication termination, to prevent replication fork collapse. Recent evidence suggests that this suppression is mediated by replication fork DNA.sup.8-10. However, it is unknown how SCF.sup.Dia2 and CUL2.sup.LRR1 discriminate terminated from elongating replisomes, to selectively ubiquitylate CMG only after termination. Here we used cryo-electron microscopy to solve high-resolution structures of budding yeast and human replisome-E3 ligase assemblies. Our structures show that the leucine-rich repeat domains of Dia2 and LRR1 are structurally distinct, but bind to a common site on CMG, including the MCM3 and MCM5 zinc-finger domains. The LRR-MCM interaction is essential for replisome disassembly and, crucially, is occluded by the excluded DNA strand at replication forks, establishing the structural basis for the suppression of CMG ubiquitylation before termination. Our results elucidate a conserved mechanism for the regulation of replisome disassembly in eukaryotes, and reveal a previously unanticipated role for DNA in preserving replisome integrity. A conserved mechanism for the regulation of replisome disassembly in eukaryotes is shown using cryo-electron microscopy, revealing a role for DNA in the preservation of replisome integrity., Author(s): Michael Jenkyn-Bedford [sup.1] , Morgan L. Jones [sup.1] , Yasemin Baris [sup.1] , Karim P. M. Labib [sup.2] , Giuseppe Cannone [sup.1] , Joseph T. P. Yeeles [sup.1] , [...]

Patients and methods: This was a prospective double-blinded multi-center randomized controlled trial conducted from April 2022 till September 2022 involving one hundred eighty women categorized into three categories, each involving 60 females who received either tranexamic acid, etamsylate or placebo just after birth of the baby. Results: Loss of blood in tranexamic acid was the same as the blood loss in etamsylate and both wer e lower than the placebo group. The difference in hemoglobin after delivery in tranexamic acid individuals was the same as etamsylate group and both of them were lower than placebo group. The occurrence of postpartum hemorrhage and blood transfusion in tranexamic acid category and etamsylate category were significantly less than placebo. Conclusions: Etamsylate is an efficiently alternative agent for tranexamic acid in decreasing blood loss with lower side effects, therefore, it can be used instead of tranexamic acid in women with contraindications or anticipated to be have higher risk to develop tranexamic acid side effects. [ABSTRACT FROM AUTHOR]

Efficient duplication of the genome requires the concerted action of helicase and DNA polymerases at replication forks (1) to avoid stalling of the replication machinery and consequent genomic instability (2-4). [...]

A method is described for inducing prolonged pausing of forks at protein barriers assembled at unique sites on a yeast chromosome, to examine for the first time the effects of pausing upon replisome integrity. The result shows that paused and stalled eukaryotic replisomes resemble each other but are regulated differently.

Author(s): Masato Kanemaki [1]; Alberto Sanchez-Diaz [1]; Agnieszka Gambus; Karim Labib (corresponding author) Analysing the role of eukaryotic proteins that are essential for cell viability requires a method by which [...]