Wednesday, June 10, 10 am, BioLabs Room 1058
See you there!
We spent the first meeting narrowing in on the system we would use for our upcoming projects. After comparing the bacterial light sensing system with that of the modified yeast 2-hybrid system a consensus was reached to attempt the yeast system first. The yeast phytochrome based system seemed more sensitive and the bistable light inducible system would give us an added element of regulation, in that the system could be rapidly reset using IR wavelengths. This would be useful in a "bio-blackboard" configuration.
As a backup though, we should be prepared to revert to the bacterial system.
The potential problem for the yeast system is that phycocyanobilin (PCB) needs to be exogenously supplemented. It may need to be extracted from a suitable (algae?) source or the bacterial PCB biosyntheis pathway may need to be cloned into yeast, if possible. Also, if using yeast as a "sender" with red-luciferase, the luciferin substrate for luciferase also needs to be added externally. Uptake should occur if the media is made acidic.
David pointed out a more recent intein system that also utilizes the same Phytochrome/PIF3 domains that the modified yeast two-hybrid system uses.
Below are schematics of the various light responsive genetic systems, including an attempt at adding an "inverter" component into the "Levskaya system".