Molecules that modulate Galphaq activity and methods of treating urinary incontinence

Abstract

The present invention provides methods that are useful for the treatment or prevention of smooth muscle disorders such as urinary incontinence and compounds that are useful in such methods.

1 . A method for screening candidate agents that modulate interaction of RGS and Gαq, said method comprising: 
 (a) contacting a screening assay system comprising a polypeptide selected from RGS and Gαq with a candidate agent under conditions whereby, but for the presence of the agent, the system provides a reference activity; and    (b) detecting a candidate agent-biased activity of the system; wherein a difference between the agent-biased activity and the reference activity indicates that the candidate agent modulates interaction of RGS and Gαq.    
     
     
         2 . The method of  claim 1  wherein said assay system comprises RGS and Gαq and said reference activity detects binding of RGS to Gαq.  
     
     
         3 . The method of  claim 1  wherein said activity is a GAP/GTPase activity.  
     
     
         4 . The method of  claim 1  wherein said contacting in (a) comprises administering said candidate agent to cultured host cells that have been genetically engineered to express said polypeptide.  
     
     
         5 . The method of  claim 1  wherein the screening assay system is a cell-free system comprising purified polypeptide.  
     
     
         6 . The method of  claim 1  wherein the screening assay system is used in a high throughput format to screen test agents in a compound library.  
     
     
         7 . The method of  claim 1  wherein the activity is selected from carbachol-induced activity and IP3 activity.  
     
     
         8 . The method of  claim 1  wherein the reference activity comprises a measurement of muscle contraction.  
     
     
         9 . The method of  claim 8  wherein said muscle is bladder muscle strips.  
     
     
         10 . The method of  claim 1  wherein said polypeptide comprises an amino acid sequence having at least 80% sequence identity with the amino acid sequence of SEQ ID NOS:_ (RGS & Gαq).  
     
     
         11 . The method of  claim 1  further comprising: testing the candidate agent in an animal model defective for RGS or Gαq, and detecting phenotypic changes relative to control animals.  
     
     
         12 . A method of modulating the interaction of an RGS polypeptide and a Gαq polypeptide comprising the step of contacting the RGS polypeptide or the Gαq polypeptide with a compound identified by the method of  claim 1 .  
     
     
         13 . A method of modulating the interaction of an RGS polypeptide and a Gαq polypeptide comprising the step of contacting the RGS polypeptide or the Gαq polypeptide with an agent capable of modulating the interaction of the RGS polypeptide and the Gαq.  
     
     
         14 . A method for identifying agents that modulate urinary incontinence, said method comprising: 
 (a) contacting a screening assay system comprising a polypeptide selected form RGS and Gαq with a candidate agent under conditions whereby, but for the presence of the agent, the system provides a reference activity; and    (b) detecting a candidate agent-biased activity of the system; and    (c) testing if the candidate agent that results in the biased activity detected in (b) modulates urinary incontinence.    
     
     
         15 . The method of  claim 12  wherein said assay system comprises RGS and Gαq and reference activity detects binding of RGS to Gαq.  
     
     
         16 . The method of  claim 12  wherein said activity is a GAP/GTPase activity.  
     
     
         17 . The method of  claim 12  wherein said contacting in (a) comprises administering said candidate agent to cultured host cells that have been genetically engineered to express said polypeptide.  
     
     
         18 . The method of  claim 12  wherein said testing in (c) is performed by administering said candidate agent to carbachol-induced bladder strips, and a reduction in muscle contraction identifies the candidate agent as capable of modulating urinary incontinence.  
     
     
         19 . A method for modulating urinary incontinence comprising contacting a vertebrate animal predetermined to have urinary incontinence with an agent that specifically binds a protein selected from the group consisting of RGS and Gαq.  
     
     
         20 . The method of  claim 17  in which the agent is a chemical binding agent.