Ecdysone receptor-based inducible gene expression system
View Patent ↗This invention relates to the field of biotechnology or genetic engineering. Specifically, this invention relates to the field of gene expression. More specifically, this invention relates to a novel inducible gene expression system and methods of modulating gene expression in a host cell for applications such as gene therapy, large-scale production of proteins and antibodies, cell-based high throughput screetng assays, functional genomics and regulation of traits in transgenic plants and animals.
1. A gene expression modulation system comprising:
a) a first gene expression cassette that is capable of being expressed in a host cell comprising a polynucleotide encoding a first polypeptide comprising:
i) a DNA-binding domain that recognizes a response element associated with a gene whose expression is to be modulated;
ii) a ligand binding domain comprising a ligand binding domain from a nuclear receptor,
b) a second gene expression cassette that is capable of being expressed in the host cell comprising a polynucleotide encoding a second polypeptide comprising:
i) a transactivation domain; and
ii) a ligand binding domain comprising a ligand binding domain from a nuclear receptor other than ultraspiracle (USP), wherein the ligand binding domains from the first polypeptide and the second polypeptide are different.
2. The gene expression modulation system according to claim 1 , further comprising a third gene expression cassette comprising:
i) a response element to which the DNA-binding domain of the first polypeptide binds;
ii) a promoter that is activated by the transactivation domain of the second polypeptide; and
iii) the gene whose expression is to be modulated.
3. The gene expression modulation system according to claim 1 , wherein the ligand binding domain of the first polypeptide is an ecdysone receptor polypeptide.
4. The gene expression modulation system according to claim 1 , wherein the ligand binding domain of the second polypeptide is a retinoid X receptor polypeptide.
5. A gene expression modulation system comprising:
a) a first gene expression cassette that is capable of being expressed in a host cell comprising a polynucleotide encoding a first polypeptide comprising:
i) a DNA-binding domain that recognizes a response element associated with a gene whose expression is to be modulated; and
ii) a ligand binding domain comprising a ligand binding domain from an ecdysone receptor; and
b) a second gene expression cassette that is capable of being expressed in the host cell comprising a polynucleotide encoding a second polypeptide comprising:
i) a transactivation domain; and
ii) a ligand binding domain comprising a ligand binding domain from a retinoid X receptor.
6. The gene expression modulation system according to claim 5 , further comprising a third gene expression cassette comprising:
i) a response element to which the DNA-binding domain of the first polypeptide binds;
ii) a promoter that is activated by the transactivation domain of the second polypeptide; and
iii) the gene whose expression is to be modulated.
7. The gene expression modulation system according to claim 5 , wherein the ligand binding domain of the first polypeoptide is encoded by a polynucleotide comprising the nucleic acid sequence of SEQ ID NO:3.
8. A gene expression modulation system comprising:
a) a first gene expression cassette that is capable of being expressed in a host cell comprising a polynucleotide encoding a first polypeptide comprising:
i) a DNA-binding domain that recognizes a response element associated with a gene whose expression is to be modulated; and
ii) a ligand binding domain comprising a ligand binding domain from a retinoid X receptor, and
b) a second gene expression cassette that is capable of being expressed in the host cell comprising a polynucleotide encoding a second polypeptide comprising:
i) a transactivation domain; and
ii) a ligand binding domain comprising a ligand binding domain from an ecdysone receptor.
9. The gene expression modulation system according to claim 8 , further comprising a third gene expression cassette comprising:
i) a response element to which the DNA-binding domain of the first polypeptide binds;
ii) a promoter that is activated by the transactivation domain of the second polypeptide; and
iii) the gene whose expression is to be modulated.
10. The gene expression modulation system according to claim 8 , wherein the ligand binding domain of the second polypeptide is encoded by a polynucleotide comprising the nucleic acid sequence of SEQ ID NO:3.