Enkurin and uses thereof
A novel protein, enkurin, that is preferentially expressed in sperm has been discovered. Enkurin binds to TRPCs including TRPC2-S, a protein encoded by TRPC2 that is not predicted to be a calcium channel subunit. The invention includes methods of identifying compounds that affect enkurin expression or activity, and are useful, e.g., for contraception and treatment of infertility.
1. A method of identifying a candidate compound that modulates the expression or activity of an enkurin polypeptide, comprising SEQ ID No. 1 or SEQ ID No. 2 the method comprising
(a) obtaining a test sample comprising a cell that can express an enkurin polypeptide comprising SEQ ID No. 1 or SEQ ID No. 2;
(b) contacting the test sample with a test compound;
(c) determining a level of expression or activity of the enkurin polypeptide in the test sample of (b);
wherein the test compound is a candidate compound for modulating enkurin expression or activity if the level of expression or activity in the test sample contacted with the test compound is different from a predetermined value.
2. The method of claim 1 , wherein enkurin activity is modulated.
3. The method of claim 1 , wherein enkurin nucleic acid expression is modulated.
4. The method of claim 1 , wherein enkurin polypeptide expression is modulated.
5. The method of claim 1 , wherein the test compound is a fusion protein.
6. The method of claim 1 , wherein enkurin expression or activity is decreased.
7. The method of claim 1 , wherein enkurin expression or activity is increased.
8. The method of claim 1 , wherein determining the level of enkurin expression or activity comprises exposing the test sample to a compound that binds to the enkurin polypeptide and detecting levels of the compound.
9. The method of claim 8 , wherein the compound that binds to the enkurin polypeptide is an antibody.
10. The method of claim 1 , wherein the enkurin polypeptide comprises SEQ ID NO:1.
11. The method of claim 1 , wherein the enkurin polypeptide comprises SEQ ID No: 2.
12. The method of claim 1 , further comprising
(d) assaying Ca 2+ influx in the presence of the test compound; and
(e) determining the amount of Ca 2+ influx in the presence of the test compound compared to a reference compound such that a difference in the amount of Ca 2+ influx indicates that the test compound is a candidate compound for modulating enkurin expression or activity.
13. A purified polypeptide consists of SEQ ID NO:1.
14. A purified polypeptide consists of SEQ ID No: 2.
15. A purified polypeptide comprises SEQ ID No: 1.
16. A purified polypeptide comprises SEQ ID No: 2.