Mechanisms of eukaryotic replisome disassembly during termination.
(A) Replisome disassembly during termination in Saccharomyces cerevisiae. SCFDia2 might be constitutively associated with the budding yeast replisome and promotes CMG ubiquitylation on its Mcm7 subunit during termination in the form of K48-linked ubiquitin chains. Alternatively, it is possible that SCFDia2 is recruited to the replisome only during termination, leading to Mcm7 ubiquitylation. CMG ubiquitylation triggers Cdc48-Ufd1-Npl4-dependent recruitment and replisome disassembly. (B) Replisome disassembly during termination in higher eukaryotes. DNA replication termination promotes de novo recruitment of Cullin2LRR1 to the terminated CMGs, which results in the ubiquitylation of Mcm7 with K48-linked ubiquitin chains. The ubiquitylated replisome is subsequently disassembled by p97-Ufd1-Npl4.