Topoisomerase II␤-binding protein (TopBP1), a human protein with eight BRCT domains, is similar to Saccharomyces cerevisiae Dpb11 and Schizosaccharomyces pombe Cut5 checkpoint proteins and closely related to Drosophila Mus101. We show that human TopBP1 is required for DNA replication and that it interacts with DNA polymerase ⑀. In S phase TopBP1 colocalizes with Brca1 to foci that do not represent sites of ongoing DNA replication. Inhibition of DNA synthesis leads to relocalization of TopBP1 together with Brca1 to replication forks, suggesting a role in rescue of stalled forks. DNA damage induces formation of distinct TopBP1 foci that colocalize with Brca1 in S phase, but not in G 1 phase. We also show that TopBP1 interacts with the checkpoint protein hRad9. Thus, these results implicate TopBP1 in replication and checkpoint functions. DNA polymerases (pol)1 play essential roles in chromosomal DNA replication and repair. In Saccharomyces cerevisiae three essential nuclear polymerases, ␣, ␦, and ⑀ have important functions in DNA replication. S. cerevisiae pol ⑀ is isolated as a complex of a catalytic subunit and three smaller subunits, Dpb2, 3, and 4 (1). This four-subunit structure is also conserved in the human enzyme, which consists of a catalytic subunit (2), a B subunit (3, 4), and two smaller subunits (5). Pol ⑀ is a proofreading DNA polymerase, which has been implicated in DNA replication, as temperature-sensitive mutants show defects in DNA replication in both S. cerevisiae and Schizosaccharomyces pombe (6 -8). Moreover, pol ⑀ is associated with origins of DNA replication and it proceeds along the replication fork (9). In human cells, pol ⑀ is associated with actively replicated cellular DNA (10) and has been shown to perform an important fraction of replicative DNA synthesis (11). Surprisingly, the catalytic domain of pol ⑀ is not essential for viability in S. cerevisiae. Instead, the C terminus, which interacts with Dpb2, exerts all of the essential functions (12).Pol ⑀ has been proposed to function in the repair of UVdamaged DNA because it is able to catalyze UV-induced DNA synthesis in vivo (13) and performs efficient gap-filling synthesis in the reconstituted nucleotide excision repair system (14). A role in base excision repair is suggested by the fact that pol ⑀ mutants fail to support repair synthesis in vitro, and repair activity can be restored by the addition of purified pol ⑀ (15). Pol ⑀ has also been proposed to function in a specialized replication process required to repair double strand breaks (16). In addition to replicative and repair roles, it has been suggested that pol ⑀ coordinates transcriptional and cell cycle responses to DNA damage and replication blocks (17).In S. cerevisiae, a BRCT domain-containing protein, Dpb11, interacts with the pol ⑀ complex and was originally identified as a suppressor of pol ⑀ catalytic and Dpb2 subunit mutants (18,19). DPB11 is an essential gene required for DNA replication (18). The inability of DPB11 mutants to restrain mitosis in the presence of inco...

Mammalian TopBP1 is a BRCT domain-containing protein whose function in mitotic cells is linked to replication and DNA damage checkpoint. Here, we study its possible role during meiosis in mice. TopBP1 foci are abundant during early prophase I and localize mainly to histone ␥-H2AX-positive domains, where DNA double-strand breaks (required to initiate recombination) occur. Strikingly, TopBP1 showed a pattern almost identical to that of ATR, a PI3K-like kinase involved in mitotic DNA damage checkpoint. In the synapsis-defective Fkbp6 ؊/؊ mouse, TopBP1 heavily stains unsynapsed regions of chromosomes. We also tested whether Schizosaccharomyces pombe Cut5 (the TopBP1 homologue) plays a role in the meiotic recombination checkpoint, like spRad3, the ATR homologue. Indeed, we found that a cut5 mutation suppresses the checkpoint-dependent meiotic delay of a meiotic recombination defective mutant, indicating a direct role of the Cut5 protein in the meiotic checkpoint. Our findings suggest that ATR and TopBP1 monitor meiotic recombination and are required for activation of the meiotic recombination checkpoint.

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Topoisomerase IIbeta binding protein 1 (TopBP1), previously shown to localise to sites of DNA damage and to stalled replication forks, has been implicated in DNA replication and in DNA damage response. In this work we showed that TopBP1 was localised in structures other than stalled replication forks. In late mitosis TopBP1 localises to centrosomes in a manner similar to other DNA damage response proteins such as BRCA1 and p53. Spindle checkpoint activation does not affect this centrosomal localisation. Moreover, in the testis, we detected high levels of TopBP1 associated with meiotic prophase chromosome cores and the X-Y pair. Together, these data suggest a direct role of TopBP1 during both mitosis and meiotic prophase I.

The scope of this research is to make quantitative estimates of the potential economic and employment impacts of renewable energy self-sufficiency. The study aims to make generalizations on a regional, or even national level, and to give directions for future research. This paper analyses direct monetary values and employment impacts in two regions, in a theoretical situation where all energy is produced by renewables from the respective region. Renewable energy, especially utilization of existing but presently unused resources, can play an important role in vitalizing regional economies, especially in rural areas. The money spent on fossil energy could be kept circulating in the regional economy. The amount spent on energy in the research areas was almost €4,860 per capita per year, totalling more than €300m annually. The existing data shows that there is the potential for self-sufficiency, or even surplus production. The results suggest that the regional economic impacts increase considerably if the region is self-sufficient in raw materials, including intermediates. On a larger scale, e.g., nationally, the loss of jobs in the fossil energy industry and the eventual variations within economies potentially based on renewable energy, will affect the overall impacts. Highlights  In rural areas, 100% renewable energy can potentially be produced.  Renewable energy can replace fossil fuels and keep money within the region.  Renewable energy can contribute up to almost €5,000 per capita to regional economies.  Employment, vitality and local business add value to the regional economy.