Investigating the role of Rts1 in DNA replication initiation

Nieduszynski, Conrad A. ORCID: and Wallis, Ana B. A. (2018) Investigating the role of Rts1 in DNA replication initiation. Wellcome Open Research, 3. ISSN 2398-502X

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Background: Understanding DNA replication initiation is essential to understand the mis-regulation of replication seen in cancer and other human disorders. DNA replication initiates from DNA replication origins. In eukaryotes, replication is dependent on cell cycle kinases which function during S phase. Dbf4-dependent kinase (DDK) and cyclin-dependent kinase (CDK) act to phosphorylate the DNA helicase (composed of mini chromosome maintenance proteins: Mcm2-7) and firing factors to activate replication origins. It has recently been found that Rif1 can oppose DDK phosphorylation. Rif1 can recruit protein phosphatase 1 (PP1) to dephosphorylate MCM and restricts origin firing. In this study, we investigate a potential role for another phosphatase, protein phosphatase 2A (PP2A), in regulating DNA replication initiation. The PP2A regulatory subunit Rts1 was previously identified in a large-scale genomic screen to have a genetic interaction with ORC2 (a DNA replication licensing factor). Deletion of RTS1 synthetically rescued the temperature-sensitive (ts-) phenotype of ORC2 mutants. Methods: We deleted RTS1 in multiple ts-replication factor Saccharomyces cerevisiae strains, including ORC2. Dilution series assays were carried out to compare qualitatively the growth of double mutant Δrts1 ts-replication factor strains relative to the respective single mutant strains. Results: No synthetic rescue of temperature-sensitivity was observed. Instead we found an additive phenotype, indicating gene products function in separate biological processes. These findings are in agreement with a recent genomic screen which found that RTS1 deletion in several ts-replication factor strains led to increased temperature-sensitivity. Conclusions: We find no evidence that Rts1 is involved in the dephosphorylation of DNA replication initiation factors.

Item Type: Article
Additional Information: Publisher Copyright: © 2018 Wallis ABA and Nieduszynski CA.
Uncontrolled Keywords: dna replication,orc2,phosphatases,rif1,rts1,medicine (miscellaneous),biochemistry, genetics and molecular biology(all),sdg 3 - good health and well-being ,/dk/atira/pure/subjectarea/asjc/2700/2701
Faculty \ School: Faculty of Science > School of Biological Sciences
Related URLs:
Depositing User: LivePure Connector
Date Deposited: 07 Sep 2022 14:31
Last Modified: 21 Oct 2022 01:37
DOI: 10.12688/wellcomeopenres.13884.1

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