| abstract |
The present invention relates to a cell which is suitable for screening a candidate agent as being an inhibitor of the metabolism of tryptophan to NAD+ and/or a modulator of NAD+ levels, which cell comprises functional genes of a pathway enabling the metabolism of tryptophan to NAD+ and wherein the cell includes a copy of an exogenous gene of said pathway, from the same or different species as the cell, which exogenous gene is under the control of an inducible or constitutive promoter and wherein any endogenous copy of the gene having the same function as the exogenous gene is a non functioning gene. The present invention also relates to populations of such cells and to methods of screening candidate agents with such cells. |