Sulfonylurea-responsive repressor proteins
Compositions and methods relating to the use of sulfonylurea-responsive repressors are provided. Compositions include polypeptides that specifically bind to an operator, wherein the specific binding is regulated by a sulfonylurea compound. Compositions also include polynucleotides encoding the polypeptides as well as constructs, vectors, prokaryotic and eukaryotic cells, and eukaryotic organisms including plants and seeds comprising the polynucleotide, and/or produced by the methods. Also provided are methods to provide a sulfonylurea-responsive repressor to a cell or organism, and to regulate expression of a polynucleotide of interest in a cell or organism, including a plant or plant cell.
1. A method of regulating transcription of a polynucleotide of interest in a host cell comprising:
(a) providing a host cell comprising the polynucleotide of interest, wherein the polynucleotide of interest is operably linked to a promoter comprising at least one operator sequence;
(b) providing a recombinant sulfonylurea-responsive repressor polypeptide that specifically binds to the operator sequence; and,
(c) providing a sulfonylurea compound, wherein the sulfonylurea binds to the polypeptide to form a complex that modifies the binding properties of the polypeptide to the operator
wherein the sulfonylurea-responsive polypeptide comprises an amino acid sequence having at least 90% sequence identity when compared to the full-length sequence set forth in SEQ ID NO:1240.
2. The method of claim 1 , wherein the host cell is a eukaryotic cell.
3. The method of claim 2 , wherein the eukaryotic cell is a plant cell.
4. The method of claim 3 , wherein the plant cell is contained in a plant or a seed.
5. The method of claim 3 , wherein the plant cell is from a monocot or a dicot.
6. The method of claim 5 , wherein the plant cell is from maize, rice, sorghum, sugarcane, barley, oat, wheat, turf grass, soybean, canola, cotton, tobacco, sunflower, safflower, or alfalfa.
7. The method of claim 1 , wherein the sulfonylurea-responsive polypeptide is selected from the group consisting of SEQ ID NO: 1232, 1233, 1240, 1241, 1242and 1243.
8. The method of claim 1 , wherein providing the sulfonylurea-responsive polypeptide comprises contacting the cell with an expression cassette comprising a promoter functional in the cell operably linked to a polynucleotide that encodes the polypeptide.
9. The method of claim 1 , wherein the polynucleotide of interest directs gene silencing, encodes an RNAi molecule, encodes a microRNA, or comprises a regulatory gene or a transcriptional regulatory gene.
10. A polynucleotide encoding a recombinant polypeptide comprising a sulfonylurea-responsive repressor that specifically binds to a polynucleotide comprising an operator sequence, wherein the binding is regulated by a sulfonylurea compound wherein the recombinant polypeptide comprises an amino acid sequence having at least 90% sequence identity when compared to the full-length sequence set forth in SEQ ID NO:1240.
11. A non-human host cell comprising the polynucleotide of claim 10 stably incorporated into its genome.
12. The host cell of claim 11 , wherein the polynucleotide is operably linked to a promoter functional in the host cell.
13. The host cell of claim 11 , wherein the host cell is a eukaryotic cell.
14. The host cell of claim 13 , wherein the eukaryotic cell is a plant cell.
15. The host cell of claim 14 , wherein the plant cell is from soybean, rice, corn or tobacco.
16. The host cell of claim 15 , wherein the host cell is contained in a plant or a seed.