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Rdh54/Tid1 inhibits Rad51-Rad54-mediated D-loop formation and limits D-loop length
Shanaya Shital Shah1, Stella Hartono2, Aurèle Piazza1,3
1Department of Microbiology and Molecular Genetics, University of California, Davis, Davis, United States.
Elife
|November 13, 2020
Summary
Rdh54/Tid1 inhibits DNA displacement loop (D-loop) formation by Rad51 and Rad54. This protein restricts D-loop length, impacting cell survival and mating-type switching in yeast.
Area of Science:
- Molecular Biology
- Genetics
- Biochemistry
Background:
- Displacement loops (D-loops) are key intermediates in homologous recombination.
- Rdh54/Tid1, a Rad54 paralog, functions with Dmc1 in meiosis and is present in somatic cells, but its somatic role is unclear.
- The interplay between Rdh54/Tid1 and Rad54 in D-loop formation requires further investigation.
Purpose of the Study:
- To elucidate the role of Rdh54/Tid1 in DNA displacement loop (D-loop) formation mediated by Rad51 and Rad54.
- To understand how Rdh54/Tid1 influences the properties and length of D-loops.
- To investigate the functional significance of Rdh54/Tid1's regulation of D-loop formation in yeast.
Main Methods:
- Utilized a novel D-loop Mapping Assay to analyze D-loop formation.
- Investigated the ATPase-independent activity of Rdh54/Tid1.
- Examined the impact of Rdh54/Tid1 on Rad51-Rad54-mediated D-loop formation and length.
Main Results:
- Rdh54/Tid1 inhibits D-loop formation by Rad51 and Rad54 in an ATPase-independent manner.
- Rdh54/Tid1 restricts the length of Rad51-Rad54-mediated D-loops.
- These alterations in D-loop properties are crucial for yeast cell survival and mating-type switching.
Conclusions:
- Rdh54/Tid1 acts as an inhibitor of D-loop formation and limits D-loop length.
- Rdh54/Tid1 and Rad54 likely compete for binding sites on Rad51 filaments.
- Rdh54/Tid1 functions as a physical impediment to Rad54 translocation, thereby regulating D-loop formation and length.
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