Methods for screening and therapeutic applications of kinesin modulators

Abstract

The present invention relates to protein modulators, especially modulators of kinesin bioactivities. The present invention provides methods for screening protein modulators, e.g., kinesin modulators that bind to a region of a kinesin and/or that modulate kinesin bioactivities. The present invention also provide methods and compositions for treatment of disorders mediated by abnormal cellular proliferation activities.

1 . A method for identifying an agent as a modulator of a kinesin:
 (a) contacting a L5 loop-containing polypeptide with a test agent; and   (b) detecting a signal indicating binding between said test agent and said L5 loop; thereby identifying said kinesin modulator,   wherein said L5 loop-containing polypeptide is KSP and the signal is fluorescence from a tryptophan residue within the L5 loop, and a reduction of fluorescence following contacting the L5 loop with the test agent indicates binding of the test agent to the L5 loop.   
     
     
         2 . The method of  claim 1 , wherein the L5 loop containing polypeptide is contacted with a compound known to bind the L5 loop in addition to the test agent, and the signal indicates that the test agent competes with the compound for binding to the L5 loop. 
     
     
         3 . The method of  claim 1 , wherein the compound is a known inhibitor of the kinesin. 
     
     
         4 . The method of  claim 1 , further comprising contacting the identified kinesin modulator with a kinesin molecule or a cell comprising a kinesin molecule, and determining an effect of the modulator on a bioactivity of said kinesin. 
     
     
         5 . The method of  claim 4 , wherein said bioactivity is mitosis, ATP hydrolysis, or bipolar spindle formation. 
     
     
         6 . The method of  claim 5 , wherein said modulator inhibits the bioactivity of said kinesin. 
     
     
         7 . The method of  claim 5 , wherein said effect is determined by determining an effect on cellular proliferation, cellular viability, motility, or morphology. 
     
     
         8 . The method of  claim 7 , wherein the effect on morphology is the production of a monopolar spindle phenotype.