Mammalian SUV39H2 proteins and isolated DNA molecules encoding them

Abstract

Murine and human Suv39h2 polypeptide and DNA molecules encoding them. Suv39h2 is a novel member of the Suv3-9 gene family. Suv39h2 is a novel component of meiotic higher order chromatin. It has histone methyltransferase activity and is required, in combination with Suv39h1, for male gametogenesis. Suv39h2 can be used in screening methods to identify modulators of its methyltransferase activity, which are useful in cancer therapy and for male contraception.

What is claimed is:  
     
         1 . Murine Suv39h2 polypeptide with the amino acid sequence as set forth in SEQ ID NO:2 or with the amino acid sequence encoded by a polynucleotide which hybridises under stringent conditions to a polynucleotide having a nucleotide sequence as set forth in SEQ ID NO:1.  
     
     
         2 . An isolated DNA molecule comprising a polynucleotide with the nucleotide sequence as set forth in SEQ ID NO:1 encoding murine Suv39h2 polypeptide or an isolated DNA molecule encoding murine Suv39h2, comprising a polynucleotide which hybridises under stringent conditions to a polynucleotide having a nucleotide sequence as set forth in SEQ ID NO:1.  
     
     
         3 . Human SUV39H2 polypeptide encoded by a polynucleotide containing the sequence of the human EST accession number AQ173625 (SEQ ID NO:3) and/or AQ494637 (SEQ ID NO:4) and/or AQ691972 (SEQ ID NO:5) and/or AQ554070 (SEQ ID NO:6), or by a polynucleotide which hybridises under stringent conditions to the said polynucleotides.  
     
     
         4 . An isolated DNA molecule encoding the human SUV39H2 polypeptide, comprising a polynucleotide containing the sequence of the human EST accession number AQ173625 (SEQ ID NO:3) and/or AQ494637 (SEQ ID NO:4) and/or AQ691972 (SEQ ID NO:5) and/or AQ554070 (SEQ ID NO:6), or an isolated DNA molecule.  
     
     
         5 . An antibody against murine Suv39h2.  
     
     
         6 . An antibody against human SUV39H2.  
     
     
         7 . A method for identifying compounds that have the ability of modulating mammalian male gametogenesis, wherein one or more Suv39h/SUV39H homologues required for male gametogenesis are incubated, in the presence of the substrate(s) for the histone methyltransferase activity of Suv39h/SUV39H and in the presence of a methyl donor, with test compounds and that the modulating effect of the test compounds on the histone methyltransferase activity of the Suv39h/SUV39H homologue(s) is determined.  
     
     
         8 . The method of  claim 7 , wherein the methyltransferase with Suv39h-like activity methylates histone H3 at lysine 9.  
     
     
         9 . The method of  claim 8 , wherein the methyltransferase is Suv39h2/SUV39H2.  
     
     
         10 . The method of  claim 7 , wherein in a first step, the Suv39h/SUV39H homologue is Suv39h2/SUV39H2, and a compound identified as an inhibitor or activitor of Suv39h2/SUV39H2 is, in a second step, confirmed to be also an inhibitor or activator of Suv39h1/SUV39H1 histone methyltransferase activity.  
     
     
         11 . The method of any one of  claims 7  to  10 , wherein the substrate is histone H3 or an N-terminal fragment thereof that contains the methylation site at lysine 9.  
     
     
         12 . The method of  claim 11 , wherein the histone H3 N-terminal fragment has the amino acid sequence as set forth in SEQ ID NO:7.  
     
     
         13 . The method of any one of claims  7  to 12, wherein the methyl donor is methionine or S-adenosyl-L-methionine.  
     
     
         14 . The method of any one of  claims 7  to  13 , wherein the methyl group of the methyl donor carries a detectable label.  
     
     
         15 . The method of  claim 14 , wherein the methyl donor carries a chromogenic label and the methyltransferase activity is determined by measuring the change in colour upon transfer of the methyl group to the substrate.  
     
     
         16 . The method of  claim 14 , wherein the methyl donor carries a radioactive label and the methyltransferase activity is determined by measuring the radioactivity transferred to the substrate upon transfer of the methyl group.  
     
     
         17 . The method of any one of  claims 7  to  13 , wherein the methyltransferase activity is determined immunologically by quantifying the binding of an antibody specific for the methylation site to the substrate.  
     
     
         18 . The method of  claim 17 , wherein the substrate carries a detectable label.  
     
     
         19 . A compound identified in a method defined in any one of  claims 7  to  18  for use in the therapy of cancer.  
     
     
         20 . A compound identified in a method defined in any one of  claims 7  to  18  for use in contraception.  
     
     
         21 . The compound of claim  22  for use in temporary male conception.