Related Experiment Video
Updated: May 24, 2026
06:24
Real-time Observation of the DNA Strand Exchange Reaction Mediated by Rad51
Published on: February 13, 2019
Mechanistic insights into RAD51-associated protein 1 (RAD51AP1) action in homologous DNA repair
Myun Hwa Dunlop1, Eloïse Dray, Weixing Zhao
1Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, Connecticut 06520, USA.
The Journal of Biological Chemistry
|March 1, 2012
Summary
RAD51-associated protein 1 (RAD51AP1) has two DNA binding domains crucial for its function in DNA repair. Both domains are essential for RAD51AP1
Area of Science:
- Molecular Biology
- Genetics
- DNA Repair Mechanisms
Background:
- Homologous recombination (HR) is vital for genome integrity, especially after DNA damage.
- RAD51 recombinase is central to HR, and RAD51AP1 enhances its activity.
Purpose of the Study:
- To elucidate the role and mechanism of RAD51AP1 in homologous recombination.
- To identify and characterize the DNA binding domains of RAD51AP1.
Main Methods:
- Site-directed mutagenesis to create RAD51AP1 variants with impaired DNA binding domains.
- Cellular assays to assess the function of RAD51AP1 mutants in DNA repair.
Main Results:
- RAD51AP1 possesses two distinct DNA binding domains.
- Both DNA binding domains are required for RAD51AP1's maximal activity in cells.
- Mutants lacking functional DNA binding domains are impaired in homologous recombination repair.
Conclusions:
- The two DNA binding domains of RAD51AP1 are indispensable for its function in homologous recombination.
- Understanding these domains provides mechanistic insight into RAD51AP1's role in DNA repair.
Related Concept Videos
02:31Homologous Recombination
The basic reaction of homologous recombination (HR) involves two chromatids that contain DNA sequences sharing a significant stretch of identity. One of these sequences uses a strand from another as a template to synthesize DNA in an enzyme-catalyzed reaction. The final product is a novel amalgamation of the two substrates. To ensure an accurate recombination of sequences, HR is restricted to the S and G2 phases of the cell cycle. At these stages, the DNA has been replicated already and the...
02:37Restarting Stalled Replication Forks
DNA replication is initiated at sites containing predefined DNA sequences known as origins of replication. DNA is unwound at these sites by the minichromosome maintenance (MCM) helicase and other factors such as Cdc45 and the associated GINS complex.The unwound single strands are protected by replication protein A (RPA) until DNA polymerase starts synthesizing DNA at the 5’ end of the strand in the same direction as the replication fork. To prevent the replication fork from falling apart, a...
02:36DNA Damage can Stall the Cell Cycle
In response to DNA damage, cells can pause the cell cycle to assess and repair the breaks. However, the cell must check the DNA at certain critical stages during the cell cycle. If the cell cycle pauses before DNA replication, the cells will contain twice the amount of DNA. On the other hand, if cells arrest after DNA replication but before mitosis, they will contain four times the normal amount of DNA. With a host of specialized proteins at their disposal,cells must use the right protein at...
02:36DNA Damage Can Stall the Cell Cycle
In response to DNA damage, cells can pause the cell cycle to assess and repair the breaks. However, the cell must check the DNA at certain critical stages during the cell cycle. If the cell cycle pauses before DNA replication, the cells will contain twice the amount of DNA. On the other hand, if cells arrest after DNA replication but before mitosis, they will contain four times the normal amount of DNA. With a host of specialized proteins at their disposal,cells must use the right protein at...
01:02Long-patch Base Excision Repair
Since the discovery of the two BER pathways, there has been a debate about how a cell chooses one pathway over the other and the factors determining this selection. Numerous in vitro experiments have pointed out multiple determinants for the sub-pathway selection. These are:
02:04Fixing Double-strand Breaks
The double-stranded structure of DNA has two major advantages. First, it serves as a safe repository of genetic information where one strand serves as the back-up in case the other strand is damaged. Second, the double-helical structure can be wrapped around proteins called histones to form nucleosomes, which can then be tightly wound to form chromosomes. This way, DNA chains up to 2 inches long can be contained within microscopic structures in a cell. A double-stranded break not only damages...