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Detection of Homologous Recombination Intermediates via Proximity Ligation and Quantitative PCR in Saccharomyces cerevisiae
Published on: September 11, 2022
SirA enforces diploidy by inhibiting the replication initiator DnaA during spore formation in Bacillus subtilis
Jennifer K Wagner1, Kathleen A Marquis, David Z Rudner
1Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, MA 02115, USA.
Abstract:
How cells maintain their ploidy is relevant to cellular development and disease. Here, we investigate the mechanism by which the bacterium Bacillus subtilis enforces diploidy as it differentiates into a dormant spore. We demonstrate that a sporulation-induced protein SirA (originally annotated YneE) blocks new rounds of replication by targeting the highly conserved replication initiation factor DnaA. We show that SirA interacts with DnaA and displaces it from the replication origin. As a result, expression of SirA during growth rapidly blocks replication and causes cell death in a DnaA-dependent manner. Finally, cells lacking SirA over-replicate during sporulation. These results support a model in which induction of SirA enforces diploidy by inhibiting replication initiation as B. subtilis cells develop into spores.
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