Regulation Of Homologous Recombination: Robustness Through Reversibility
Abstract
Homologous recombination is a critical pathway to maintain genome stability. The signature reactions in recombination of homology search and DNA strand invasion are carefully regulated. The Rad51‐ssDNA filament, which conducts the homology search, exists in a balance between assembly and disassembly, where specific motor proteins, such as Srs2 in yeast, lead to disassembly of the filament. This process reverses Rad51 filament formation as a mechanism of anti‐recombination. A second mechanism of anti‐recombination is the disruption of the primary DNA strand invasion product, the nascent D‐loop. While it has been thought that the disruption of D‐loops is being conducted by motor proteins and helicases, we showed that nascent D‐loop dissolution by Top3‐Rmi1 represents a distinct mechanism of anti‐recombination. Another level of regulation affects the outcome of recombination, the formation of crossover or non‐crossover products. The Synthesis‐Dependent Strand Annealing (SDSA) pathway of DNA double‐strand break repair envisions the disruption of the extended D‐loop after DNA synthesis to enable the annealing of the extended invading strand with the second end of the double strand break. Hence, different enzymes are needed to target the nascent D‐loop and the extended D‐loop to achieve anti‐recombination or anti‐crossover (= pro‐SDSA), respectively.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Apr 01, 2016
- Source ID
- 10.1096/fasebj.30.1_supplement.239.1
Entities
People
- Wolf‐dietrich Heyer
Organizations
- National Institutes of Health
- United States Department of Defense
- University of California