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Bacillus subtilis responses to stress

Environmental stresses. Bacillus subtilis responses to stress. Competence development. Chemotaxis/motility. Sporulation. Degradation enzymes. Heat shock stress. clpC. Clp family in E. coli - degradation of many regulatory proteins. ClpC function in B. subtilis. stress. clpC. ClpC.

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Bacillus subtilis responses to stress

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  1. Environmental stresses Bacillus subtilis responses to stress Competence development Chemotaxis/motility Sporulation Degradation enzymes

  2. Heat shock stress clpC Clp family in E. coli - degradation of many regulatory proteins

  3. ClpC function in B. subtilis stress clpC ClpC comK Late competence genes ComK

  4. RNA polymerase sigma factor H is essential for normal competence development SigH is also required for the transcription of many sporulation genes

  5. H H H H H H H H H H H H H Exponential growth Sporulation SigH expression in cell cycle

  6. H H H H H H H H H H H H H Exponential growth Sporulation SigH half-life increases during sporulation

  7. H H H H H H H H H H Exponential growth Sporulation SigH half-life increases during sporulation

  8. H H H H H H H H Exponential growth Sporulation SigH half-life increases during sporulation

  9. What needs to happen in order for ClpC to be involved in SigH expression? ClpC has to be expressed when SigH is at the onset of sporulation

  10. Transcriptional fusion used to detect clpC expression: clpC bgaB A B heat shock response Integrate into chromosome Evaluate beta-galactosidase activity in various situations

  11. T3.5 T3.5 >T4 >T4 Induction of clpC expression sporulation T0 T4 wildtype sigB null spo0H null clpCS (deletion mutation)

  12. What needs to happen in order for ClpC to be involved in SigH expression? ClpC has to be expressed when SigH is at the onset of sporulation ClpC should have an effect on SigH accumulation

  13. clpC+ clpCS T-0.5 T-0.5 T0 T0 T1 T1 T2 T2 T3 T3 T4 T4 Western blot analysis of σH accumulation Possible causes of this result: Deficiency in active degradation of SigH Deficiency in active transcription of spo0H

  14. Degradation of SigH vs. Transcription of spo0H spo0H::bgaB fusion spo0H bgaB No difference between spo0H expression in wildtype and clpC deletion mutant strains. SigH half-life analysis: 50% of SigH disappeared after 12 minutes in wildtype. At 12 min, 85% of SigH was still present in clpCS.

  15. Accumulation of SigH is due to a deficiency in its degradation. Because this occurred in the clpCC deletion mutant, it appears that ClpC is somehow involved in the degradation of H.

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