The RecA-Dependent SOS Response Is Active and Required for Processing of DNA Damage during Bacillus subtilis Sporulation

• Published in: PloS one 2016-03, Vol.11 (3), p.e0150348-e0150348
• Main Authors: Ramírez-Guadiana, Fernando H, Barajas-Ornelas, Rocío Del Carmen, Corona-Bautista, Saúl U, Setlow, Peter, Pedraza-Reyes, Mario
• Format: Article
• Language: English
• Subjects: Alkylation; Bacillus; Bacillus subtilis; Bacillus subtilis - drug effects; Bacillus subtilis - genetics; Bacillus subtilis - physiology; Bacterial genetics; Bacterial Proteins - genetics; Bacterial spores; beta-Galactosidase - genetics; Biology and Life Sciences; Compartments; Damage; Deoxyribonucleic acid; DNA; DNA damage; DNA Damage - drug effects; DNA Damage - genetics; DNA repair; DNA, Bacterial - genetics; Galactosidase; Gene expression; Gene Expression Regulation, Bacterial - drug effects; Gene Expression Regulation, Bacterial - genetics; Genetic aspects; Kinases; Laboratories; Lac Operon - genetics; Lesions; Medicine and Health Sciences; Mitomycin - pharmacology; Mitomycin C; Physical sciences; Physiological aspects; Plasmids; Radiation; Rec A Recombinases - genetics; RecA protein; Repair; Research and Analysis Methods; SOS response; SOS Response (Genetics) - drug effects; SOS Response (Genetics) - genetics; Sporangia; Spores, Bacterial - drug effects; Spores, Bacterial - genetics; Sporulation; Ultraviolet radiation; Ultraviolet Rays
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0150348

The expression of and role played by RecA in protecting sporulating cells of Bacillus subtilis from DNA damage has been determined. Results showed that the DNA-alkylating agent Mitomycin-C (M-C) activated expression of a PrecA-gfpmut3a fusion in both sporulating cells' mother cell and forespore compartments. The expression levels of a recA-lacZ fusion were significantly lower in sporulating than in growing cells. However, M-C induced levels of ß-galactosidase from a recA-lacZ fusion ~6- and 3-fold in the mother cell and forespore compartments of B. subtilis sporangia, respectively. Disruption of recA slowed sporulation and sensitized sporulating cells to M-C and UV-C radiation, and the M-C and UV-C sensitivity of sporangia lacking the transcriptional repair-coupling factor Mfd was significantly increased by loss of RecA. We postulate that when DNA damage is encountered during sporulation, RecA activates the SOS response thus providing sporangia with the repair machinery to process DNA lesions that may compromise the spatio-temporal expression of genes that are essential for efficient spore formation.