Related Experiment Videos
CDC45 is required in conjunction with CDC7/DBF4 to trigger the initiation of DNA replication
J C Owens1, C S Detweiler, J J Li
1Department of Microbiology and Immunology, University of California, San Francisco, CA 94143-0414, USA.
Summary
The CDC45 gene product is essential for initiating DNA replication in yeast. It functions in late G1, working with CDC7/DBF4 to activate replication origins after prereplicative complex assembly.
Area of Science:
- Molecular Biology
- Cell Cycle Regulation
- DNA Replication
Background:
- DNA replication initiation is a critical cell cycle event.
- Prereplicative complexes assemble at origins of replication after mitosis.
- The CDC45 gene product is known to be required for DNA replication.
Purpose of the Study:
- To elucidate the precise role and timing of the CDC45 gene product in DNA replication initiation.
- To investigate the functional relationship between CDC45 and other key regulators of the G1/S phase transition.
Main Methods:
- Cell cycle analysis in Saccharomyces cerevisiae.
- Analysis of protein levels and function throughout the cell cycle.
- Investigating genetic interactions between CDC45 and CDC7/DBF4.
Main Results:
- Cdc45p is present at constant levels but functions specifically in late G1.
- CDC45-deficient cells fail to initiate DNA replication.
- Cdc45p and the kinase Cdc7p/Dbf4p exhibit functional interdependence.
Conclusions:
- CDC45 acts in late G1 to trigger DNA replication initiation.
- CDC45 functions in conjunction with CDC7/DBF4 to activate replication origins.
- This activation occurs after the assembly of prereplicative complexes.