Many thanks to Drew for the yummy and fun dinner at Bertucci's. It was great to see and meet most of this summer's team. I liked a lot of the ideas that were kicking around.
The discussion about TNT-sensing bacteria made me look up that reference. There may be more recent ones but the one I was thinking of is
Looger LL, Dwyer MA, Smith JJ, Hellinga HW. Computational design of receptor and sensor proteins with novel functions. Nature (2003)423:185-190
They design TNT-binding receptors in this paper as well as L-lactate and seretonin ones (which I'd totally forgotten about but which are also very cool). And the authors hook-up their designed receptors to the chemotactic system of the cells, allowing these cells to tumble and swim their way toward higher concentrations of their ligand. Of course they never got them to sing when they got there...
Regarding the protein-initiated receptor coupling that we talked about during dinner, the protein I forgot the name of is E5 found in HPV (Human Papilloma Virus). E5 binds to PDGF (platelet derived growth factor, which is a RTK) and also forms dimers/trimers. When E5 dimerize, they cause PDGF to dimerize with them, causing constitutive kinase activity. This is why E5 is a viral oncogene.