IGEM:Stanford/2009/Light Sensitive Promoters

Project Summary

• A light-sensitive promoter and/or a time sensitive promoter.
• We would also like to have a promoter that will turn genes "on" at specific times, such as every minute (or whatever designated time you want). In this way, you could enable cyclic cellular functions.
• The applications associated with this tool are expansive innature, and we would make great contributions to biobricks with these promoters.

Experiment Ideas

The Voigt Lab did this Voigt Lab:

• Engineering Two-Component Systems. Bacteria respond to their environment using membrane-bound sensors, which interact with intracellular response regulators to control gene expression. These systems are remarkably modular and new sensors can be built using in vitro recombination to swap protein domains. We demonstrated this process by fusing the light sensing domain from a cyanobacterium with a signal transduction domain from E. coli to create a strain that can respond to light. We are refining this strategy to create new sensors as well as studying the downstream signal processing events that occur once a sensor is activated. (Copied from their home page referenced above)
  
• This process would probably take longer than 10 weeks, but is there a way we can shorten it to fit our goals?

Questions/Discussion

• Chris - How is this different from synthetic oscillators? ie. The repressilator and the Hasty oscillations?

• Tuesday 4/21 discussion
  • Photosystems coupling - take advantage of pH gradients to take advantage of pH change induced by photosynthesis
  • Rhodopsins light sensitivity -> cAMP -> signal cascade
    • rhodopsin is sensitive to conformational changes in retinal that are caused by light
  • chR2
  • nPHR
  • Look at light triggered drug delivery systems.
  • Perhaps, we should focus on improving control of oscillations. Will need modeling experts, maybe Michael?

Important/Interesting Papers

• natural oscillator in cyanobacteria: A Circadian Timing Mechanism in the Cyanobacteria
• Hasty Lab tunable oscillator in E.coli synthetic oscillator
• Fussenegger tunable mammalian oscillator using antisence RNA
• Elowitz's repressilator (the original)
• Collins's lab oscillator
• Neuromodulation Circuit Breakers...