Patent ID: 7358086

Claim:
A cell comprising: an accumulation or degradation of a metabolic product; a nucleic acid encoding a peptide binding site and an effector gene; a first chimeric protein comprising a nucleic acid binding protein that binds said peptide binding site where said nucleic acid binding protein is attached to said metabolic product or to a ligand that binds to said metabolic product; and a second chimeric protein comprising an expression control protein attached to said metabolic product or to said ligand that binds to said metabolic product such that when said first chimeric protein comprises said metabolic product, said second chimeric protein comprises said ligand and when said first chimeric protein comprises said ligand, said second chimeric protein comprises said metabolic product; wherein said cell is a cell selected from the group consisting of SW480, SW48, DLD-1, HCT-116,HT29, 293, U-20S, T-47D, MCF-7, HeLa, A549, Hep G2, a mammalian cell, and a Jarkat cell.