Team:TPHS SanDiego

In an effort to expand the toolkit available to synthetic biologists, we've taken a system natively responsible for transcriptional activation and modified it to control transcriptional repression. The LasR system from Pseudomonas Aeruginosa requires the presence of a small molecule, C12-3-oxo-AHL, to induce activation of the Plas promoter. By modifying the -10 and -35 sites of the promoter, as well as shifting the location of the LasR binding sites, the new Plas promoter (Plas*) was changed from an inducible to a repressible promoter. Through adding this second functionality, the Plas* promoter could be used in conjunction with a wildtype Plas promoter to control two separate genes whose expression levels are always out of sync. Furthermore, if the bacteria are transfected with a plasmid encoding LasI, the bacteria will be able to turn off gene expression at a critical population density, instead of only being able to turn on gene expression.

We are Team Berkeley, a cohesive unit of 7 undergraduates and 3 advisers. Earlier this year we planned a complex and risky project, given the short amount of time iGEM made available. We quickly learned each others strengths and weaknesses and developed standard systems of organizational management in order to synchronize our efforts for the many parallel tasks at hand. We created protocols, shared them with one another, and worked together on troubleshooting. Using google docs to keep up with the status of cloning projects, the results of assays, material logistics, or the final steps required to complete a project ensured that through the months of hard work, we fine-tuned our ability to work together. As a team, we have learned firsthand how the synthetic biology community relies on the goal-oriented cooperation of skilled individuals from very different backgrounds and with very different skill sets. Some of us have strong engineering backgrounds while others of us have strong biology backgrounds, but we all share a desire to build synthetic biological systems that solve human problems. We are proud of the project that we have created which we will present at the Jamboree together in October.