Pablo, a polypeptide that interacts with Bcl-xL, and uses related thereto

Abstract

The present invention relates, at least in part, to polypeptides which include Bcl-xL binding domains, novel Bcl-xL binding domains of Pablo polypeptides, nucleic acid molecules encoding such polypeptides, and uses thereof. For example, such polypeptides and nucleic acid molecules are useful in modulating apoptosis, particularly in neural cells, as well as in the treatment or prevention of disorders that can benefit from modulation of cell death.

What is claimed is:  
     
         1 . An isolated nucleic acid molecule comprising a nucleotide sequence selected from the group consisting of: 
 a) a nucleotide sequence encoding an isolated mammalian Bcl-xL binding domain, wherein said isolated mammalian Bcl-xL binding domain has 70% amino acid sequence identity with a Bcl-xL binding domain set forth in SEQ ID NO:2.    b) a nucleotide sequence encoding an isolated mammalian Bcl-xL binding domain, wherein said nucleotide sequence hybridizes to the complement a nucleotide sequence set forth in SEQ ID NO:1 which encodes a Bcl-xL binding domain in 6×SSC at 45° C., followed by one or more washes in 0.2×SSC, 0.1% SDS at 50-65° C.    c) a nucleotide sequence encoding an isolated mammalian Bcl-xL binding domain as shown in SEQ. ID NO:1.    
     
     
         2 . The isolated nucleic acid molecule of  claim 1  wherein the isolated Bcl-xL binding domain consists of amino acids 419-559 or amino acids 429-559 of SEQ. ID NO:2.  
     
     
         3 . The isolated nucleic acid molecule of  claim 1 , wherein said isolated mammalian Bcl-xL binding domain modulates apoptosis in a neural cell.  
     
     
         4 . The isolated nucleic acid molecule of  claim 1 , wherein said nucleic acid molecule encodes a fusion protein.  
     
     
         6 . An isolated polypeptide selected from the group consisting of: 
 a) a polypeptide comprising an isolated mammalian Bcl-xL binding domain, wherein said isolated Bcl-xL binding domain consists of an amino acid sequence having at least 70% identity with a Pablo Bcl-xL binding domain shown in SEQ. ID NO:2.    b) a polypeptide comprising a Bcl-xL binding domain, wherein said Bcl-xL binding domain consists of an amino acid sequence having at least 70% identity with a Pablo Bcl-xL binding domain shown in SEQ ID NO:2, provided said polypeptide is not a full-length Pablo polypeptide    c) polypeptide comprising a Bcl-xL binding domain shown in SEQ. ID NO:2.    
     
     
         7 . A polypeptide comprising an isolated Bcl-xL binding domain set forth in SEQ ID NO:2.  
     
     
         8 . The polypeptide of  claim 7 , within which a conservative amino acid substitution has been made.  
     
     
         9 . A polypeptide consisting of an isolated Bcl-xL binding domain set forth in SEQ ID NO:2.  
     
     
         10 . The polypeptide of  claim 6 , wherein said isolated Bcl-xL binding domain consists of amino acids 419-559 or amino acids 429-559.  
     
     
         11 . The polypeptide of  claim 6 , wherein said isolated Bcl-xL binding domain modulates apoptosis in a neural cell.  
     
     
         12 . A fusion protein comprising a first polypeptide consisting of an isolated Bcl-xL binding domain and a second, non-Pablo polypeptide.  
     
     
         13 . An isolated nucleic acid molecule which is antisense to the portion of SEQ ID NO:1 which encodes a Bcl-xL binding domain.  
     
     
         14 . A vector comprising the nucleic acid molecule of  claim 1 .  
     
     
         15 . A neural cell line stably expressing a heterologous Pablo polypeptide or an isolated Bcl-xL binding domain set forth in SEQ ID NO:2.  
     
     
         16 . A nonhuman transgenic animal which contains cells carrying a nucleic acid molecule encoding an isolated mammalian Bcl-xL binding domain.  
     
     
         17 . A method of modulating apoptosis in a cell comprising modulating the activity of a Pablo polypeptide or Bcl-xL binding domain thereof.  
     
     
         18 . A method of modulating apoptosis in a cell comprising modulating the expression of a Pablo polypeptide or Bcl-xL binding domain thereof.  
     
     
         19 . A method for treating a nervous system disorder in a subject comprising modulating the expression or activity of Pablo in a cell of the subject to thereby treat a nervous system disorder in the subject.  
     
     
         20 . A method for identifying a compound that modulates the pro-apoptotic activity of a Bcl-xL binding domain, comprising: 
 contacting a cell expressing a Bcl-xL binding domain with a test compound and;    determining the ability of the test compound to modulate the activity of a Bcl-xL binding domain to thereby identify a compound that modulates the pro-apoptotic activity of a Bcl-xL binding domain.    
     
     
         21 . A method for identifying a compound that modulates the pro-apoptotic activity of a Bcl-xL binding domain, comprising: 
 contacting a cell-free mixture comprising a Bcl-xL binding domain with a test compound and;    determining the ability of the test compound to modulate the activity of a Bcl-xL binding domain to thereby identify a compound that modulates the pro-apoptotic activity of a Bcl-xL binding domain.