Abstract
RNA-DNA hybrids are naturally occurring obstacles that must be overcome by the DNA replication machinery. In the absence of RNase H enzymes, RNA-DNA hybrids accumulate, resulting in replication stress, DNA damage and compromised genomic integrity. We demonstrate that Mph1, the yeast homolog of Fanconi anemia protein M (FANCM), is required for cell viability in the absence of RNase H enzymes. The integrity of the Mph1 helicase domain is crucial to prevent the accumulation of RNA-DNA hybrids and RNA-DNA hybrid-dependent DNA damage, as determined by Rad52 foci. Mph1 forms foci when RNA-DNA hybrids accumulate, e.g. in RNase H or THO-complex mutants and at short telomeres. Mph1, however is a double-edged sword, whose action at hybrids must be regulated by the Smc5/6 complex. This is underlined by the observation that simultaneous inactivation of RNase H2 and Smc5/6 results in Mph1-dependent synthetic lethality, which is likely due to an accumulation of toxic recombination intermediates. The data presented here support a model, where Mph1's helicase activity plays a crucial role in responding to persistent RNA-DNA hybrids.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Cell Cycle Proteins / genetics*
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Cell Cycle Proteins / metabolism
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DEAD-box RNA Helicases / genetics*
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DEAD-box RNA Helicases / metabolism*
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DNA / metabolism
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DNA Damage*
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DNA Repair
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DNA Replication / genetics
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DNA Replication / physiology
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RNA Helicases / metabolism
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RNA, Fungal / genetics*
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RNA, Fungal / metabolism
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Ribonuclease H / genetics
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Saccharomyces cerevisiae / genetics
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Saccharomyces cerevisiae Proteins / genetics*
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Saccharomyces cerevisiae Proteins / metabolism*
Substances
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Cell Cycle Proteins
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RNA, Fungal
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SMC5 protein, S cerevisiae
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SMC6 protein, S cerevisiae
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Saccharomyces cerevisiae Proteins
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DNA
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Ribonuclease H
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MPH1 protein, S cerevisiae
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DEAD-box RNA Helicases
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RNA Helicases
Grants and funding
This work was supported by grants from the Spanish Ministry of Economy and Competitiveness (BFU2013-42918-P & BFU2016-75058-P),
http://www.mineco.gob.es/portal/site/mineco; Junta de Andalucía (BIO1238),
http://www.juntadeandalucia.es/index.html; the European Research Council (ERC2014 AdG669898 TARLOOP),
https://erc.europa.eu; the Danish Council for Independent Research,
http://ufm.dk/en/research-and-innovation/councils-and-commissions/the-danish-council-for-independent-research; the Villum Foundation,
http://veluxfoundations.dk/da; European Research Council (ERCStG, no. 242905); BMBF-GerontoSys II network AGENET (FKZ0315898),
https://www.bmbf.de; CancerTelSys (01ZX1302) in the E:med program of the German Federal Ministry of Education and Research (BMBF),
http://www.sys-med.de/de/; Instituto Carlos III (Spanish Ministry of Health) to JLB; Scientific Foundation of the Spanish Association Against Cancer to BGG; Fundação para a Ciência e a Tecnologia to SS; EMBO/Marie Curie co-fund fellowship to SLG (ALTF 9-2010),
http://www.embo.org/funding-awards/fellowships; European Union (FEDER). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.