Novel protein associated with cell stress response

Abstract

A stress-phosphorylated endoplasmic reticulum protein, Nogo B, is provided. The protein is hyperphosphorylated as a result of exposure of cells to stress. Two transcripts of Nogo B are identified in human tissues, and the longer transcript is predominant in human brain tumor samples.

1 . A purified polypeptide, the amino acid sequence of which comprises a sequence at least 90% identical to SEQ ID NO:2, or an immunogenic fragment thereof.  
     
     
         2 . The purified polypeptide of  claim 1 , the amino acid sequence of which comprises a sequence at least 95% identical to SEQ ID NO:2.  
     
     
         3 . The purified polypeptide of  claim 1 , the amino acid sequence of which comprises a sequence at least 98% identical to SEQ ID NO:2.  
     
     
         4 . The purified polypeptide of  claim 1 , the amino acid sequence of which comprises a sequence at least 99% identical to SEQ ID NO:2.  
     
     
         5 . The purified polypeptide of  claim 1 , the amino acid sequence of which comprises SEQ ID NO:2.  
     
     
         6 . The purified polypeptide of  claim 1 , the amino acid sequence of which consists of SEQ ID NO:2  
     
     
         7 . The purified polypeptide of  claim 1 , comprising up to 10 conservative amino acid substitutions, insertions or deletions.  
     
     
         8 . The purified polypeptide of  claim 7 , comprising up to 10 conservative amino acid substitutions.  
     
     
         9 . The purified polypeptide of  claim 7 , comprising up to 5 conservative amino acid substitutions.  
     
     
         10 . The purified polypeptide of  claim 1 , comprising up to 7 conservative amino acid substitutions.  
     
     
         11 . The purified polypeptide of  claim 1 , wherein phosphorylation of the polypeptide is increased during cellular stress.  
     
     
         12 . The purified polypeptide of  claim 11 , wherein the cellular stress is one or more of ultraviolet irradiation, DNA damage, osmotic stress, ionic stress, or oxidative stress.  
     
     
         13 . The polypeptide of  claim 1 , wherein the polypeptide binds specifically to an antibody that binds specifically to Nogo B.  
     
     
         14 . The antibody of  claim 13 , wherein the antibody is a monoclonal antibody, a polyclonal antibody, a chimeric antibody, a human antibody, a humanized antibody, a single-chain antibody, or a Fab fragment.  
     
     
         15 . The purified polypeptide of  claim 1 , the amino acid sequence of which comprises amino acids 2-373 of SEQ ID NO:2.  
     
     
         16 . A purified polypeptide comprising: 
 (a) amino acids 1-197 of SEQ ID NQ:2; and    (b) amino acids 236-373 of SEQ ID NO:2,    wherein the amino acid residue corresponding to residue 197 of SEQ ID NO: 2 is joined by a peptide bond to the amino acid residue corresponding to residue 236 of SEQ ID NO:2.    
     
     
         17 . A purified polypeptide comprising: 
 (a) amino acids 1-288 of SEQ ID NO:2; and    (b) amino acids 336-373 of SEQ ID NO:2,    wherein the amino acid residue corresponding to residue 288 of SEQ ID NO:2 is joined by a peptide bond to the amino acid residue corresponding to residue 336 of SEQ ID NO:2.    
     
     
         18 . A purified polypeptide comprising: 
 (a) amino acids 1-197 of SEQ ID NO:2; and    (b) amino acids 236-288 of SEQ ID NO:2; and    (c) amino acids 336-373 of SEQ ID NO:2;    wherein the amino acid residue corresponding to residue 197 of SEQ ID NO:2 is joined by a peptide bond to the amino acid residue corresponding to residue 236 of SEQ ID NO:2, and the amino acid residue corresponding to residue 288 of SEQ ID NO: 2 is joined by a peptide bond to the amino acid residue corresponding to residue 336 of SEQ ID NO:2.