Patent ID: 6723531
Filing Date: 2004-04-20
Classification: A01K,A61K,C07K,C12N

Abstract:
A method for modulating the expression of an exogenous gene in an isolated cell containing:(i) a modified ecdysone receptor which, in the presence of a ligand therefor, and optionally in the further presence of a silent partner therefor, binds to a response element, wherein said modified ecdysone receptor comprises: (a) a ligand binding domain that binds to an ecdysteroid, (b) a DNA-binding domain obtained from a DNA-binding protein, which binds to said response clement; and (c) an activation domain of a transcription factor, wherein at least one of said DNA-binding domain or said activation domain is not obtained from a native ecdysone receptor, with the proviso that when said activation domain is derived from a glucocorticoid receptor, said DNA-binding domain is not derived from a glucocorticoid receptor or a E. coli LexA protein; and (ii) a DNA construct comprising said exogenous gene under the control of said response element, wherein said response element: (a) is a modified response element which comprises, in any order, a first half-site and a second half-site separated by a spacer of 0-5 nucleotides; wherein said first half-site has the sequence: â€”RGBNNMâ€”, â€ƒwherein each R is independently selected from A or G; each B is independently selected from G, C, or T; each N is independently selected from A, T, C, or G; and each M is independently selected from A or C; with the proviso that at least 4 nucleotides of each â€”RGBNNMâ€”group of nucleotides are identical with the nucleotides at comparable positions of the sequence â€”AGGTCAâ€”; and wherein said second half-site is obtained from a glucocorticoid receptor subfamily response element, (b) binds to said modified ecdysone receptor, and (c) does not bind to farnesoid X receptor (FXR); said method comprising providing to the cell an effective amount of one or more ligands for said modified ecdysone receptor; wherein said one or more ligands are not normally present in the cell; and wherein said one or more ligands are not toxic to said cell.