Mitogen-activated protein kinase MEK6 and methods of use therefor

Abstract

Compositions and methods are provided for potentiating the activity of the mitogen-activated protein kinase p38. In particular the mitogen-activated protein kinase kinase MEK6, and variants thereof that stimulate phosphorylation of p38 are provided. Such compounds may be used, for example, for therapy of diseases associated with the p38 cascade and to identify antibodies and other agents that inhibit or activate signal transduction via p38.

1 . A polypeptide comprising the amino acid sequence provided in SEQ ID NO:2 or a variant thereof that differs only in conservative substitutions and/or modifications at no more than 10% of the amino acid residues.  
     
     
         2 . A constitutively active variant of a polypeptide according to  claim 1 .  
     
     
         3 . A polypeptide comprising the amino acid sequence provided in SEQ ID NO:2 modified at no more than 10% of the amino acid residues, such that said polypeptide is rendered constitutively inactive.  
     
     
         4 . An isolated DNA molecule encoding a polypeptide according to any of claims  1 - 3 .  
     
     
         5 . An isolated DNA molecule comprising the nucleotide sequence provided in SEQ ID NO:1.  
     
     
         6 . A recombinant expression vector comprising a DNA molecule according to  claim 4 .  
     
     
         7 . A host cell transformed or transfected with an expression vector according to  claim 6 .  
     
     
         8 . A method for phosphorylating p38 comprising contacting p38 with a polypeptide according to either of claims  1  or  2 , thereby phosphorylating p38.  
     
     
         9 . A method for activating a member of the p38 cascade in an organism, comprising administering to an organism a polypeptide according to either of claims  1  or  2 , thereby activating a member of the p38 cascade.  
     
     
         10 . The method of  claim 9  wherein the member of the p38 cascade is p38.  
     
     
         11 . A method for screening for an agent that inhibits signal transduction via the p38 cascade, comprising: 
 (a) contacting a candidate agent with a polypeptide according to either of claims  1  or  2 ; and    (b) subsequently measuring the ability of said polypeptide to activate p38, and thereby evaluating the ability of the compound to inhibit signal transduction via the p38 cascade.    
     
     
         12 . A method for screening for an agent that stimulates signal transduction via the p38 cascade, comprising: 
 (a) contacting a candidate agent with a polypeptide according to either of claims  1  or  2 ; and    (b) subsequently measuring the ability of said polypeptide to activate p38, and thereby evaluating the ability of the compound to stimulate signal transduction via the p38 cascade.    
     
     
         13 . A monoclonal antibody that binds to a polypeptide according to either of claims  1  or  2 .  
     
     
         14 . A monoclonal antibody according to  claim 13 , wherein said antibody inhibits the phosphorylation of p38 by said polypeptide.  
     
     
         15 . A method for treating a patient afflicted with a disease associated with the p38 cascade, comprising administering to a patient a compound that inhibits the phosphorylation of p38 by MEK6.  
     
     
         16 . The method of  claim 15  wherein said compound is a monoclonal antibody.  
     
     
         17 . The method of  claim 15  wherein said compound comprises a nucleotide sequence.  
     
     
         18 . A method for detecting MEK6 kinase activity in a sample comprising evaluating the ability of the sample to phosphorylate p38, thereby detecting MEK6 kinase activity in the sample.  
     
     
         19 . A kit for detecting MEK6 kinase activity in a sample, comprising p39 in combination with MEK6 and a suitable buffer.  
     
     
         20 . A method for identifying a composition which affects MBK6 kinase activity, comprising: 
 (a) incubating the composition and MEK6 kinase or polynucleotide encoding the kinase, wherein the step of incubation is carried out under conditions and for a time sufficient to allow the components to interact; and    (b) measuring the effect of the composition on MEK6 kinase or polynucleotide encoding the kinase.    
     
     
         21 . A method of treating an immunologically related disorder associated with MEK6 kinase activity, comprising administering to a subject having the disorder a therapeutically effective amount of a compound which modulates MEK6 kinase activity.