Dataset Information

Mph1p promotes gross chromosomal rearrangement through partial inhibition of homologous recombination.

ABSTRACT: Gross chromosomal rearrangement (GCR) is a type of genomic instability associated with many cancers. In yeast, multiple pathways cooperate to suppress GCR. In a screen for genes that promote GCR, we identified MPH1, which encodes a 3'-5' DNA helicase. Overexpression of Mph1p in yeast results in decreased efficiency of homologous recombination (HR) as well as delayed Rad51p recruitment to double-strand breaks (DSBs), which suggests that Mph1p promotes GCR by partially suppressing HR. A function for Mph1p in suppression of HR is further supported by the observation that deletion of both mph1 and srs2 synergistically sensitize cells to methyl methanesulfonate-induced DNA damage. The GCR-promoting activity of Mph1p appears to depend on its interaction with replication protein A (RPA). Consistent with this observation, excess Mph1p stabilizes RPA at DSBs. Furthermore, spontaneous RPA foci at DSBs are destabilized by the mph1Delta mutation. Therefore, Mph1p promotes GCR formation by partially suppressing HR, likely through its interaction with RPA.

SUBMITTER: Banerjee S

PROVIDER: S-EPMC2442200 | biostudies-literature | 2008 Jun

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Mph1p promotes gross chromosomal rearrangement through partial inhibition of homologous recombination.

Banerjee Soma S Smith Stephanie S Oum Ji-Hyun JH Liaw Hung-Jiun HJ Hwang Ji-Young JY Sikdar Nilabja N Motegi Akira A Lee Sang Eun SE Myung Kyungjae K

The Journal of cell biology 20080601 7

Gross chromosomal rearrangement (GCR) is a type of genomic instability associated with many cancers. In yeast, multiple pathways cooperate to suppress GCR. In a screen for genes that promote GCR, we identified MPH1, which encodes a 3'-5' DNA helicase. Overexpression of Mph1p in yeast results in decreased efficiency of homologous recombination (HR) as well as delayed Rad51p recruitment to double-strand breaks (DSBs), which suggests that Mph1p promotes GCR by partially suppressing HR. A function f ...[more]

PMID: 18591428

Similar Datasets

Project description:Bacterial MutS proteins are subdivided into two families, MutS1 and MutS2. MutS1 family members recognize DNA replication errors during their participation in the well-characterized mismatch repair (MMR) pathway. In contrast to the well-described function of MutS1, the function of MutS2 in bacteria has remained less clear. In Helicobacter pylori and Thermus thermophilus, MutS2 has been shown to suppress homologous recombination. The role of MutS2 is unknown in the Gram-positive bacterium Bacillus subtilis In this work, we investigated the contribution of MutS2 to maintaining genome integrity in B. subtilis We found that deletion of mutS2 renders B. subtilis sensitive to the natural antibiotic mitomycin C (MMC), which requires homologous recombination for repair. We demonstrate that the C-terminal small MutS-related (Smr) domain is necessary but not sufficient for tolerance to MMC. Further, we developed a CRISPR/Cas9 genome editing system to test if the inducible prophage PBSX was the underlying cause of the observed MMC sensitivity. Genetic analysis revealed that MMC sensitivity was dependent on recombination and not on nucleotide excision repair or a symptom of prophage PBSX replication and cell lysis. We found that deletion of mutS2 resulted in decreased transformation efficiency using both plasmid and chromosomal DNA. Further, deletion of mutS2 in a strain lacking the Holliday junction endonuclease gene recU resulted in increased MMC sensitivity and decreased transformation efficiency, suggesting that MutS2 could function redundantly with RecU. Together, our results support a model where B. subtilis MutS2 helps to promote homologous recombination, demonstrating a new function for bacterial MutS2. Cells contain pathways that promote or inhibit recombination. MutS2 homologs are Smr-endonuclease domain-containing proteins that have been shown to function in antirecombination in some bacteria. We present evidence that B. subtilis MutS2 promotes recombination, providing a new function for MutS2. We found that cells lacking mutS2 are sensitive to DNA damage that requires homologous recombination for repair and have reduced transformation efficiency. Further analysis indicates that the C-terminal Smr domain requires the N-terminal portion of MutS2 for function in vivo Moreover, we show that a mutS2 deletion is additive with a recU deletion, suggesting that these proteins have a redundant function in homologous recombination. Together, our study shows that MutS2 proteins have adapted different functions that impact recombination.

Dataset Information

Mph1p promotes gross chromosomal rearrangement through partial inhibition of homologous recombination.

Publications

Mph1p promotes gross chromosomal rearrangement through partial inhibition of homologous recombination.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets