Cdc45 Limits Replicon Usage in Mammalian Cells
Author Information
Author(s): Philip G. Wong, Sherry L. Winter, Elena Zaika, Thinh V. Cao, Umut Oguz, John M. Koomen, Joyce L. Hamlin, Mark G. Alexandrow
Primary Institution: Moffitt Cancer Center and Research Institute
Hypothesis
How does the stoichiometry of pre-replication complexes (preRCs) affect DNA replication in mammalian cells?
Conclusion
Cdc45 is rate-limiting for DNA replication in somatic cells, affecting the efficiency and size of replicons.
Supporting Evidence
- Mammalian cells have a low density of preRCs, which limits the availability of Cdc45.
- Cdc45 levels are stable but very low throughout S-phase.
- Microinjection of additional Cdc45 increases DNA replication activity significantly.
Takeaway
Cdc45 is a special helper that is needed for DNA to copy itself, but there isn't enough of it in cells, which makes the copying process slower and less efficient.
Methodology
The study used immunoblotting and quantitative mass spectrometry to measure the levels of preRC components in mammalian cells.
Limitations
The study primarily used CHO cells, which may not fully represent other mammalian cell types.
Digital Object Identifier (DOI)
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