Swi1 and Swi3 Are Components of a Replication Fork Protection Complex in Fission Yeast
- 1 October 2004
- journal article
- research article
- Published by Informa UK Limited in Molecular and Cellular Biology
- Vol. 24 (19), 8342-8355
- https://doi.org/10.1128/mcb.24.19.8342-8355.2004
Abstract
Swi1 is required for programmed pausing of replication forks near the mat1 locus in the fission yeast Schizosaccharomyces pombe. This fork pausing is required to initiate a recombination event that switches mating type. Swi1 is also needed for the replication checkpoint that arrests division in response to fork arrest. How Swi1 accomplishes these tasks is unknown. Here we report that Swi1 copurifies with a 181-amino-acid protein encoded by swi3+. The Swi1-Swi3 complex is required for survival of fork arrest and for activation of the replication checkpoint kinase Cds1. Association of Swi1 and Swi3 with chromatin during DNA replication correlated with movement of the replication fork. swi1Δ and swi3Δ mutants accumulated Rad22 (Rad52 homolog) DNA repair foci during replication. These foci correlated with the Rad22-dependent appearance of Holliday junction (HJ)-like structures in cells lacking Mus81-Eme1 HJ resolvase. Rhp51 and Rhp54 homologous recombination proteins were not required for viability in swi1Δ or swi3Δ cells, indicating that the HJ-like structures arise from single-strand DNA gaps or rearranged forks instead of broken forks. We propose that Swi1 and Swi3 define a fork protection complex that coordinates leading- and lagging-strand synthesis and stabilizes stalled replication forks.Keywords
This publication has 64 references indexed in Scilit:
- Identification of Protein Complexes Required for Efficient Sister Chromatid CohesionMolecular Biology of the Cell, 2004
- RNase-sensitive DNA modification(s) initiates S. pombe mating-type switchingGenes & Development, 2004
- Generating Crossovers by Resolution of Nicked Holliday JunctionsMolecular Cell, 2003
- Mus81-Eme1 and Rqh1 Involvement in Processing Stalled and Collapsed Replication ForksJournal of Biological Chemistry, 2002
- DNA replication checkpointCurrent Biology, 2001
- Nuclear reorganization and homologous chromosome pairing during meiotic prophase require C. elegans chk-2Genes & Development, 2001
- Evidence from mutational specificity studies that yeast DNA polymerases δ and ϵ replicate different DNA strands at an intracellular replication forkJournal of Molecular Biology, 2000
- Ribosomal DNA Replication in the Fission Yeast,Schizosaccharomyces pombeExperimental Cell Research, 1998
- The Schizosaccharomyces pombe cdc6 gene encodes the catalytic subunit of DNA polymerase δMolecular Genetics and Genomics, 1997
- [56] Molecular genetic analysis of fission yeast Schizosaccharomyces pombeMethods in enzymology, 1991