Search for mutants of the helicase MCM defective in DNA damage tolerance
DNA damage compromises genome integrity and can lead to cell death. Cells have evolved a variety of processes to respond to DNA damage including the DNA damage tolerance (DDT) response. DDT pathways promote the bypass of blocking lesions by DNA polymerases during DNA replication, and the subsequent...
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| Tipo de recurso: | tesis de maestría |
| Fecha de publicación: | 2018 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/180649 |
| Acceso en línea: | http://hdl.handle.net/10261/180649 |
| Access Level: | acceso abierto |
| Palabra clave: | DNA damage tolerance MCM Replication |
| Sumario: | DNA damage compromises genome integrity and can lead to cell death. Cells have evolved a variety of processes to respond to DNA damage including the DNA damage tolerance (DDT) response. DDT pathways promote the bypass of blocking lesions by DNA polymerases during DNA replication, and the subsequent filling of the ssDNA left behind the fork. Two distinct DDT mechanisms have been characterized. One is translesion synthesis (TLS), which uses specialized TLS polymerases that have the ability to replicate across DNA lesions. The other is the error-free template switching (TS) mechanism, which uses homologous recombination (HR) proteins to bypass the damage and filling the ssDNA gaps using the sister chromatid as a template. The binding of HR proteins to the damage is coupled to the replication process during DDT. A potential candidate to promote this binding is the replicative helicase MCM, which interacts physically with the homologous recombination proteins Rad51 and Rad52. In this work, we have searched for MMS sensitive mutants of MCM subunits to demonstrate the implication of MCM in DDT. In addition, we have analyzed the putative role of Mcm4-T355 in DDT. We have found that both mutations in Mcm2 and the replacement of Mcm4-T355 by either a phosphomimetic or a phosphomutant residue cause sensitivity to methyl methane sulfonate (MMS), connecting genetically the helicase MCM with the DDT response. |
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