TIR1 is the E3 ubiquitin ligase associated with the Auxin pathway. It is currently the best known F-box protein for integration into yeast, as other F-box proteins from Arabidopsis have acclimated to less thermally variable environments and have low efficiency and expression in yeast cells. TIR1, when loaded with auxin, will bind more efficiently to its substrate, our protein of interest, and will attract ubiquitin to this complex as a signal for degradation. Once ubiquitinated, this whole complex is sent to the 26s proteasome for digestion. We modified TIR1 with a Myc tag for verification once integrated into yeast cells.
Template:Nevada/TheAuxinSystem
From 2014.igem.org
Amplified and tagged TIR1 was then engineered to join a promoter, pTEF, and a reporter, GFP. This whole insert was attached to a bacterial vector and transformed with NEB 10 beta competent cells onto LB-ampicillin agar plates in the preliminary stages. After successful colony growth, we extracted this DNA, purified it, and transformed into yeast cells. Initially we had used an ADH1 promoter but kept producing errors. We switched to a promoter known to work not only with GFP but also with yeast, since that was our final destination.
Amplified and tagged TIR1 was then engineered to join a promoter, pTEF, and a reporter, GFP. This whole insert was attached to a bacterial vector and transformed with NEB 10 beta competent cells onto LB-ampicillin agar plates in the preliminary stages. After successful colony growth, we extracted this DNA, purified it, and transformed into yeast cells. Initially we had used an ADH1 promoter but kept producing errors. We switched to a promoter known to work not only with GFP but also with yeast, since that was our final destination.