Cell type specific compartmentalization of the Bacillus subtilis stress response transcription factor Sigma B

ANIBAL GOÑI; MARCELO B. MENDEZ; ROBERTO GRAU

Mar del Plata

Congreso; XLIII Reunión Nacional de la Sociedad Argentina de investigación en Bioquímica y Biología Molecular; 2007

SAIB

B. subtilis is a soil bacterium, and hence temperature changes, starvation, and solar radiation would constitute common environmental stresses. Stress resistance in is governed by the master transcription factor sigma B (SigB). We showed in previous reports that SigB is dramatically induced after a temperature downshift from 37°C to 20°C. Loss of SigB reduces stationary-phase viability of cold-adapted cells 10 to 15-fold. Here, we show that SigB is exclusively trapped in the pre-spore compartment of during the development of the spore. The presence in the spore prepares it for future stress. Spores of sigB mutants present a significant reduction in germination rate compared to the wild type strain in alcohol stressing germination medium. Sigma B is shown to be necessary for appropriated function of germination receptors (GerBK) under stress conditions. Moreover, it was observed a delay in the outgrowth for the sigB mutant when we compared it with wild type spores under the same conditions. Importantly, we found a decrease in the viability of mutant spores when they were exposed to extreme conditions as acid or UV-C light. These experiments are discussed in the context of the lithopanspermia theory and the novel role, discovered in this work, of sigmaBas a “Trojan horse” hidden in the dormant spore. starvation, and solar radiation would constitute common environmental stresses. Stress resistance in is governed by the master transcription factor sigma B (SigB). We showed in previous reports that SigB is dramatically induced after a temperature downshift from 37°C to 20°C. Loss of SigB reduces stationary-phase viability of cold-adapted cells 10 to 15-fold. Here, we show that SigB is exclusively trapped in the pre-spore compartment of during the development of the spore. The presence in the spore prepares it for future stress. Spores of sigB mutants present a significant reduction in germination rate compared to the wild type strain in alcohol stressing germination medium. Sigma B is shown to be necessary for appropriated function of germination receptors (GerBK) under stress conditions. Moreover, it was observed a delay in the outgrowth for the sigB mutant when we compared it with wild type spores under the same conditions. Importantly, we found a decrease in the viability of mutant spores when they were exposed to extreme conditions as acid or UV-C light. These experiments are discussed in the context of the lithopanspermia theory and the novel role, discovered in this work, of sigmaBas a “Trojan horse” hidden in the dormant spore. starvation, and solar radiation would constitute common environmental stresses. Stress resistance in is governed by the master transcription factor sigma B (SigB). We showed in previous reports that SigB is dramatically induced after a temperature downshift from 37°C to 20°C. Loss of SigB reduces stationary-phase viability of cold-adapted cells 10 to 15-fold. Here, we show that SigB is exclusively trapped in the pre-spore compartment of during the development of the spore. The presence in the spore prepares it for future stress. Spores of sigB mutants present a significant reduction in germination rate compared to the wild type strain in alcohol stressing germination medium. Sigma B is shown to be necessary for appropriated function of germination receptors (GerBK) under stress conditions. Moreover, it was observed a delay in the outgrowth for the sigB mutant when we compared it with wild type spores under the same conditions. Importantly, we found a decrease in the viability of mutant spores when they were exposed to extreme conditions as acid or UV-C light. These experiments are discussed in the context of the lithopanspermia theory and the novel role, discovered in this work, of sigmaBas a “Trojan horse” hidden in the dormant spore. starvation, and solar radiation would constitute common environmental stresses. Stress resistance in is governed by the master transcription factor sigma B (SigB). We showed in previous reports that SigB is dramatically induced after a temperature downshift from 37°C to 20°C. Loss of SigB reduces stationary-phase viability of cold-adapted cells 10 to 15-fold. Here, we show that SigB is exclusively trapped in the pre-spore compartment of during the development of the spore. The presence in the spore prepares it for future stress. Spores of sigB mutants present a significant reduction in germination rate compared to the wild type strain in alcohol stressing germination medium. Sigma B is shown to be necessary for appropriated function of germination receptors (GerBK) under stress conditions. Moreover, it was observed a delay in the outgrowth for the sigB mutant when we compared it with wild type spores under the same conditions. Importantly, we found a decrease in the viability of mutant spores when they were exposed to extreme conditions as acid or UV-C light. These experiments are discussed in the context of the lithopanspermia theory and the novel role, discovered in this work, of sigmaBas a “Trojan horse” hidden in the dormant spore. is a soil bacterium, and hence temperature changes, starvation, and solar radiation would constitute common environmental stresses. Stress resistance in is governed by the master transcription factor sigma B (SigB). We showed in previous reports that SigB is dramatically induced after a temperature downshift from 37°C to 20°C. Loss of SigB reduces stationary-phase viability of cold-adapted cells 10 to 15-fold. Here, we show that SigB is exclusively trapped in the pre-spore compartment of during the development of the spore. The presence in the spore prepares it for future stress. Spores of sigB mutants present a significant reduction in germination rate compared to the wild type strain in alcohol stressing germination medium. Sigma B is shown to be necessary for appropriated function of germination receptors (GerBK) under stress conditions. Moreover, it was observed a delay in the outgrowth for the sigB mutant when we compared it with wild type spores under the same conditions. Importantly, we found a decrease in the viability of mutant spores when they were exposed to extreme conditions as acid or UV-C light. These experiments are discussed in the context of the lithopanspermia theory and the novel role, discovered in this work, of sigmaBas a “Trojan horse” hidden in the dormant spore.