Method of altering glycosylation of proteins in response to nojirimycin glucuronide in a plant cell expressing glucuronidase

Novel pro-drugs and methods for their use to alter the growth and biological characteristics of living cells, tissues, or whole organisms are described. Such cells may include animal cells, plant cells and bacterial cells. The methods allow for selective activation of the pro-drugs at or near transformant host cells expressing a gene for an enzyme that activates the pro-drugs. Pro-drugs according to a preferred embodiment of the invention are conjugates of a bioactive compound and a chemical group that is capable of being cleaved from the bioactive compound by action of an enzyme. Methods according to this invention include, (a) introducing into targeted cells a gene encoding an enzyme and (b) administering a pro-drug, wherein the enzyme releases the pro-drug from conjugation. In a preferred embodiment of the invention, the gene encoding the enzyme is a marker gene. Methods according to a preferred embodiment of the invention include altering protein production in a plant cell such as altering glycosylation of a protein produced by the plant cell.