Team:Paris Bettencourt/SinOp

From 2011.igem.org

Team IGEM Paris 2011

The Bacillus subtilis sin operon

The sin operon of Bacillus subtilis can be turned into a bistable switch [1]. This cellular system has evolved to deal with short-term adaptation to environmental fluctuation by implementation of the appropriate stress responses such as sporulation.

Sporulation is a highly regulated phenomenon as it has a crucial role in stress response and is therefore under a huge selective pressure. It has been demonstrated that the sin operon is central to the timing and early dynamics of this network [2].

As shown by the scheme this operon is under control of the repressor SinR. Derepression is mediated by the antirepressor SinI [3]. Sporulation is also dependent on the master regulator Spo0A [4].

Overexpression of KinA, a kinase protein which phosphorylates Spo0AP, can trigger sporulation with high efficiency in cells in the exponential phase in rich medium by artificial induction [5]. Then, the activated form of Spo0AP induces the expression of SinI, which in turn inactivates SinR. The combined effect of positive regulation by Spo0AP and the inactivation of the negative regulator SinR triggers the sporulation pathway. We use SpoIIA gene as a reporter since it is is one of the first to be expressed when sporulation occurs [6].

In our design we want to diffuse kinA through the nanotubes in order to trigger sporulation in neighbouring cells, that are supposed to produce gfp once spoIIA will be activated.

For this design we used strains IIA/GFP (Veening et al 2006) and also IDJ011 Phyperspank-

References

  1. C. a Voigt, D. M. Wolf, and A. P. Arkin, “The Bacillus subtilis sin operon: an evolvable network motif.,” Genetics, vol. 169, no. 3, pp. 1187-202, Mar. 2005.
  2. J.-willem Veening, O. P. Kuipers, S. Brul, K. J. Hellingwerf, and R. Kort, “Effects of Phosphorelay Perturbations on Architecture , Sporulation , and Spore Resistance in Biofilms of Bacillus subtilis ‡,” Society, vol. 188, no. 8, pp. 3099-3109, 2006.
  3. Y. Chai, F. Chu, R. Kolter, and R. Losick, “Bistability and biofilm formation in Bacillus subtilis.,” Molecular microbiology, vol. 67, no. 2, pp. 254-63, Jan. 2008.
  4. M. Fujita and R. Losick, “Evidence that entry into sporulation in Bacillus subtilis is governed by a gradual increase in the level and activity of the master regulator Spo0A,” Genes & Development, pp. 2236-2244, 2005.
  5. P. Eswaramoorthy, D. Duan, J. Dinh, A. Dravis, S. N. Devi, and M. Fujita, “The threshold level of the sensor histidine kinase KinA governs entry into sporulation in Bacillus subtilis.,” Journal of bacteriology, vol. 192, no. 15, pp. 3870-82, Aug. 2010.
  6. M. Microbiology, “Chapter 3 Phosphatases modulate the bistable sporulation gene expression pattern in Bacillus subtilis,” Molecular Microbiology, vol. 1494, pp. 1481-1494, 2005.

Retrieved from "http://2011.igem.org/Team:Paris_Bettencourt/SinOp"