Related Experiment Video
Updated: Jul 16, 2026

Real-time Observation of the DNA Strand Exchange Reaction Mediated by Rad51
Published on: February 13, 2019
Fission yeast Swi5/Sfr1 and Rhp55/Rhp57 differentially regulate Rhp51-dependent recombination outcomes
Yufuko Akamatsu1, Yasuhiro Tsutsui, Takashi Morishita
1International Graduate School of Arts and Sciences, Yokohama City University, Yokohama, Kanagawa, Japan.
Abstract:
Several accessory proteins referred to as mediators are required for the full activity of the Rad51 (Rhp51 in fission yeast) recombinase. In this study, we analyzed in vivo functions of the recently discovered Swi5/Sfr1 complex from fission yeast. In normally growing cells, the Swi5-GFP protein localizes to the nucleus, where it forms a diffuse nuclear staining pattern with a few distinct foci. These spontaneous foci do not form in swi2Delta mutants. Upon UV irradiation, Swi5 focus formation is induced in swi2Delta mutants, a response that depends on Sfr1 function, and Sfr1 also forms foci that colocalize with damage-induced Rhp51 foci. The number of UV-induced Rhp51 foci is partially reduced in swi5Delta and rhp57Delta mutants and completely abolished in an swi5Delta rhp57Delta double mutant. An assay for products generated by HO endonuclease-induced DNA double-strand breaks (DSBs) reveals that Rhp51 and Rhp57, but not Swi5/Sfr1, are essential for crossover production. These results suggest that Swi5/Sfr1 functions as an Rhp51 mediator but processes DSBs in a manner different from that of the Rhp55/57 mediator.
More Related Videos
Related Concept Videos
Conservative Site-specific Recombination and Phase Variation
The recognition sites for Cre recombinase called LoxP...
Restarting Stalled Replication Forks
Homologous Recombination
Homologous Recombination
Crossing Over
Protein Complexes with Interchangeable Parts
The SCF ubiquitin ligase is a protein complex of five individual proteins. This complex attaches ubiquitin to other target proteins to mark them for degradation. In order to...

