Control of DNA Replication in Reconstituted Nuclei
This extract was created in the absence of an abstract.
Excerpt
Eukaryotic DNA replication has been remarkably difficult to reconstitute in cell-free systems. Although efficient systems have been developed for analysis of viral DNA replication in vitro, efficient initiation of cellular DNA replication has only been confirmed in extracts of amphibian eggs (Blow and Laskey 1986, 1988; Newport 1987; Hutchinson et al. 1987; for review, see Laskey et al. 1989). A key feature of egg extracts is their capacity for nuclear assembly (Lohka and Masui 1983,1984; Blow and Laskey 1986; Newport 1987). Thus, they reassemble nuclear envelopes around demembranated chromatin, and they assemble purified DNA into chromatin and pseudonuclei (for review, see Laskey and Leno 1990). Here we argue that these activities are not coincidental but that the complex structure of the cell nucleus plays a crucial role in both the mechanism and the regulation of eukaryotic DNA replication.
In particular, first we consider the spatial organization of replication forks within...
