TY - JOUR
T1 - Human Mcm10 regulates the catalytic subunit of DNA polymerase-α and prevents DNA damage during replication
AU - Chattopadhyay, Sharbani
AU - Bielinsky, Anja Katrin
PY - 2007/10
Y1 - 2007/10
N2 - In Saccharomyces cerevisiae, minichromosome maintenance protein (Mcm) 10 interacts with DNA polymerase (pol)-α and functions as a nuclear chaperone for the catalytic subunit, which is rapidly degraded in the absence of Mcm10. We report here that the interaction between Mcm10 and pol-α is conserved in human cells. We used a small interfering RNA-based approach to deplete Mcm10 in HeLa cells, and we observed that the catalytic subunit of pol-α, p180, was degraded with similar kinetics as Mcm10, whereas the regulatory pol-α subunit, p68, remained unaffected. Simultaneous loss of Mcm10 and p180 inhibited S phase entry and led to an accumulation of already replicating cells in late S/G2 as a result of DNA damage, which triggered apoptosis in a subpopulation of cells. These phenotypes differed considerably from analogous studies in Drosophila embryo cells that did not exhibit a similar arrest. To further dissect the roles of Mcm10 and p180 in human cells, we depleted p180 alone and observed a significant delay in S phase entry and fork progression but little effect on cell viability. These results argue that cells can tolerate low levels of p180 as long as Mcm10 is present to "recycle" it. Thus, human Mcm10 regulates both replication initiation and elongation and maintains genome integrity.
AB - In Saccharomyces cerevisiae, minichromosome maintenance protein (Mcm) 10 interacts with DNA polymerase (pol)-α and functions as a nuclear chaperone for the catalytic subunit, which is rapidly degraded in the absence of Mcm10. We report here that the interaction between Mcm10 and pol-α is conserved in human cells. We used a small interfering RNA-based approach to deplete Mcm10 in HeLa cells, and we observed that the catalytic subunit of pol-α, p180, was degraded with similar kinetics as Mcm10, whereas the regulatory pol-α subunit, p68, remained unaffected. Simultaneous loss of Mcm10 and p180 inhibited S phase entry and led to an accumulation of already replicating cells in late S/G2 as a result of DNA damage, which triggered apoptosis in a subpopulation of cells. These phenotypes differed considerably from analogous studies in Drosophila embryo cells that did not exhibit a similar arrest. To further dissect the roles of Mcm10 and p180 in human cells, we depleted p180 alone and observed a significant delay in S phase entry and fork progression but little effect on cell viability. These results argue that cells can tolerate low levels of p180 as long as Mcm10 is present to "recycle" it. Thus, human Mcm10 regulates both replication initiation and elongation and maintains genome integrity.
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U2 - 10.1091/mbc.E06-12-1148
DO - 10.1091/mbc.E06-12-1148
M3 - Article
C2 - 17699597
AN - SCOPUS:34948895494
SN - 1059-1524
VL - 18
SP - 4085
EP - 4095
JO - Molecular biology of the cell
JF - Molecular biology of the cell
IS - 10
ER -