Compositions and methods for regulating sas1r

Abstract

The present invention provides compositions and methods useful for regulating fertilization and for use as a contraceptive based on the discovery herein of an oocyte specific protein, SAS1R (Sperm Acrosomal SLLP1 Receptor), which is a sperm protein receptor. Six SAS1R variants, including the full length SAS1R, were identified. mSLLP1 and SAS1R co-localized to oocytes and to acrosomes of acrosome-reacted sperm. Interactions between mSLLP1 and SAS1R were demonstrated by far-western analysis, in a yeast two-hybrid system under stringent selection conditions, and by immunoprecipitation of SAS1R by anti-mSLLP1 as well as the converse. Purified recombinant SAS1R was found to have protease activity, to inhibit fertilization in-vitro, and to induce an immune response in females. Together, the results suggest SAS1R is a proteolytically active, oocyte and early embryo specific oolemmal metalloprotease receptor for the sperm intra-acrosomal ligand SLLP1 and is a target for regulating fertilization and as a contraceptive.

1 . A method of inhibiting fertilization by inhibiting an immunogenic oocyte stage specific metalloprotease sperm protein receptor, further wherein inhibition of said metalloprotease inhibits fertilization, said method comprising contacting an egg with a pharmaceutical composition comprising an effective fertilization-inhibiting amount of at least one inhibitor of SAS1R and a pharmaceutically-acceptable carrier, thereby inhibiting fertilization. 
     
     
         2 . The method of  claim 1 , wherein said inhibitor is selected from the group consisting of an antibody directed against SAS1R, purified SAS1R or a fragment or homolog thereof, an antisense oligonucleotide complementary to a sequence of a nucleic acid comprising a sequence encoding SAS1R, a compound, an aptamer, and an RNAi. 
     
     
         3 . The method of  claim 2 , wherein SAS1R comprises an amino acid sequence selected from the group consisting of SEQ ID NO:6 or SEQ ID NO:23. 
     
     
         4 . The method of  claim 3 , wherein said inhibitor inhibits SAS1R protease activity. 
     
     
         5 . The method of  claim 3 , wherein said inhibitor inhibits the interaction of SAS1R with a SLLP protein. 
     
     
         6 . The method of  claim 5 , wherein at least one of said inhibitors is a SAS1R protein, or a fragment or homolog thereof, or a SLLP protein, or a fragment or homolog thereof. 
     
     
         7 . The method of  claim 6 , wherein SAS1R has an amino acid sequence selected from the group consisting of SEQ ID NOs:6, 8, 10, 19, 20, 21, and 23, or a fragment or homolog thereof. 
     
     
         8 . The method of  claim 6 , wherein SLLP has an amino acid sequence selected from the group consisting of SEQ ID NOs:12, 14, 16, and 18, or a fragment or homolog thereof. 
     
     
         9 . The method of  claim 7 , wherein the inhibitor is an antibody directed against a SAS1R sequence selected from the group consisting of SEQ ID NOs:6, 8, 10, 19, 20, 21, and 23, or a fragment or homolog thereof. 
     
     
         10 . The method of  claim 9 , wherein said antibody is selected from the group consisting of a polyclonal antibody, a monoclonal antibody, a chimeric antibody, a humanized antibody, and a synthetic antibody. 
     
     
         11 . The method of  claim 9 , wherein said antibody binds to about amino acids 1-120 of an amino acid sequence selected from the group consisting of SEQ ID NOs:6, 8, 10, 19, 20, 21, and 23. 
     
     
         12 . The method of  claim 3 , wherein said pharmaceutical composition is administered to a subject via a route selected from the group consisting of intranasal, topical, oral, transdermal, intravaginal, intramuscular, and intravenous. 
     
     
         13 . The method of  claim 12 , wherein said composition is administered as a controlled-release formulation. 
     
     
         14 . The method of  claim 6 , wherein at least two different proteins, or homologs, fragments, or derivatives thereof are administered. 
     
     
         15 . The method of  claim 14 , wherein the proteins, or homologs and fragments, thereof are administered in a mixture of approximately equimolar concentrations. 
     
     
         16 . The method of  claim 6 , wherein the amount of protein, or fragments or homolog thereof administered is between about 0.001 mg/kg body weight and about 100 mg/kg body weight. 
     
     
         17 . The method of  claim 1 , wherein said method is reversible. 
     
     
         18 .- 23 . (canceled) 
     
     
         24 . A pharmaceutical composition comprising at least one inhibitor identified by the method of claim  18  and a pharmaceutically acceptable carrier. 
     
     
         25 . A compound identified by the method of claim  18 , wherein said compound is an inhibitor of SAS1R protease activity, function, or levels. 
     
     
         26 .- 34 . (canceled) 
     
     
         35 . A method of inducing an immune response in a subject wherein said response is directed to an immunogenic oocyte stage specific metalloprotease sperm protein receptor, further wherein inhibition of said metalloprotease inhibits fertilization, said method comprising administering to the subject a pharmaceutical composition comprising an effective immune response-inducing amount of a protein comprising an amino acid sequence encoding SAS1R or a fragment or homolog thereof, thereby inducing an immune response in a subject. 
     
     
         36 . The method of  claim 35 , wherein said subject is a female. 
     
     
         37 . The method of  claim 36 , wherein said SAS1R has an amino acid sequence selected from the group consisting of SEQ ID NOs:6, 8, 10, 19, 20, 21, and 23. 
     
     
         38 . The method of  claim 35 , said pharmaceutical composition further comprising an adjuvant. 
     
     
         39 . The method of  claim 35 , said pharmaceutical composition comprising more than one SAS1R fragment or homolog thereof. 
     
     
         40 . The method of  claim 35 , wherein said immune response inhibits fertilization. 
     
     
         41 . The method of  claim 35 , wherein said pharmaceutical composition is administered more than once. 
     
     
         42 . The method of  claim 41 , wherein said pharmaceutical composition is administered at least once every six months. 
     
     
         43 . The method of  claim 41 , wherein said pharmaceutical composition is administered at least once a month. 
     
     
         44 . The method of  claim 35 , wherein said method stimulates the production of antibodies directed against a protein or peptide comprising an amino acid sequence encoding SAS1R or a fragment or homolog thereof. 
     
     
         45 . The method of  claim 44 , wherein said SAS1R or a fragment or homolog thereof has an amino acid sequence selected from the group consisting of SEQ ID NOs:6, 8, 10, 19, 20, 21, and 23, or a fragment or homolog thereof. 
     
     
         46 . The method of  claim 35 , wherein said pharmaceutical composition is administered to a subject via a route selected from the group consisting of intranasal, topical, oral, transdermal, intravaginal, intramuscular, and intravenous. 
     
     
         47 . The method of  claim 35 , wherein at least two different proteins, or homologs, fragments, or derivatives thereof are administered. 
     
     
         48 . The method of  claim 47 , wherein the proteins, or homologs and fragments, thereof are administered in a mixture of approximately equimolar concentrations. 
     
     
         49 . The method of  claim 35 , wherein the amount of protein, or fragments or homolog thereof administered is between about 0.001 mg/kg body weight and about 100 mg/kg body weight. 
     
     
         50 . The method of  claim 35 , wherein said immune response inhibits fertilization. 
     
     
         51 . The method of  claim 44 , wherein said antibodies inhibit SAS1R. 
     
     
         52 . A contraceptive target comprising an immunogenic oocyte stage specific metalloprotease, wherein:
 said oocyte specific metalloprotease functions in fertilization;   said oocyte stage specific metalloprotease is a sperm protein receptor;   said oocyte stage specific metalloprotease is found specifically in secondary and subsequent follicular stages;   inhibition of said target will not affect oocyte stem cells, including naked, primordial, and primary oocytes; and   inhibition of said target inhibits fertilization.   
     
     
         53 . The contraceptive target of  claim 52 , wherein inhibition of said target is reversible. 
     
     
         54 . The contraceptive target of  claim 52 , wherein said contraceptive target is SAS1R. 
     
     
         55 . The composition of  claim 54 , wherein SAS1R has a sequence selected from the group of amino acid sequences consisting of SEQ ID NOs 6, 8, 10, 19, 20, 21, and 23, or a fragment or homolog thereof. 
     
     
         56 . The contraceptive target of  claim 54 , wherein said oocyte stage specific metalloprotease comprises a sequence selected from the group of amino acid sequences consisting of SEQ ID NOs 6, 8, 10, 19, 20, 21, and 23, or a fragment or homolog thereof, interacts with a SLLP protein. 
     
     
         57 . The contraceptive target of  claim 56 , wherein said SLLP protein is SLLP1. 
     
     
         58 . The contraceptive target of  claim 52 , wherein said contraceptive is selected from the group consisting of a drug, an antibody, a protein, an antisense oligonucleotide complementary to a sequence of the target, and a recombinant protein comprising the sequence of the target protein or a fragment or homolog thereof.