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Cell cycle modulation of protein-DNA interactions at a human replication origin
G Abdurashidova1, S Riva, G Biamonti
1Molecular Biology Unit, International Centre for Genomic Engineering and Biotechnology, Trieste, Italy.
The EMBO Journal
|June 10, 1998
Summary
Protein-DNA interactions at a replication origin change throughout the cell cycle. These dynamic changes in DNA protection correlate with cell cycle progression and resemble events in other species.
Area of Science:
- Molecular Biology
- Cell Biology
- Genetics
Background:
- Replication origins are crucial for DNA duplication.
- Understanding protein-DNA interactions at origins is key to cell cycle regulation.
- Human lamin B2 gene origin serves as a model for studying replication initiation.
Purpose of the Study:
- To investigate dynamic protein-DNA interactions at the human lamin B2 gene replication origin.
- To correlate these interactions with cell cycle progression in synchronized IMR-90 cells.
- To compare observed interactions with known replication complex formation in yeast and Xenopus.
Main Methods:
- Utilized in vivo studies on synchronized IMR-90 cells.
- Monitored protein-DNA interactions at the lamin B2 replication origin.
- Synchronized cells at different cell cycle phases (G0, G1, S, mitosis).
Main Results:
- No DNA protection observed in G0 phase.
- An extended footprint (>100 bp) appeared in G1, peaking at G1/S border.
- Footprint reduced to 70 bp in S phase and disappeared in mitosis.
- Extended protection reappeared upon entry into the next G1 phase.
Conclusions:
- Protein-DNA interactions at the lamin B2 origin exhibit cell cycle-dependent variations.
- Observed patterns resemble pre- and post-replicative complex dynamics in yeast and Xenopus.
- These findings provide insights into replication origin regulation during the human cell cycle.