Functional domain and associated molecule of dock2 essentially required in lymphocyte migration

Abstract

The present invention is related to provide a method for screening a substance interfering in the association of DOCK2 and ELMO1, a method for screening a substance interfering in the association of ELMO1 and Tiam1, and a method for searching a therapeutic agent for immune related diseases such as allergy, autoimmune diseases, GvH, graft rejection with the use of these searching methods, and so on. It was found that in DOCK2-mutant lacking 504 amino acid residues at the N terminus of DOCK2, Rac-activating ability was significantly decreased, and that actin polymerization could not be induced, and ELMO1 was identified as a molecule binding to this domain. It was found that DOCK2 was associated to ELMO1 via SH3 domain. Moreover, it was found that ELMO1 is bound with Tiam1 functioning as Rac-specific GDP/GTP exchange factor (GEF). It was found that DOCK2 activates Rac by recruiting Tiam1 via ELMO1.

1 - 12 . (canceled) 
     
     
         13 . A method for screening a substance interfering in the association of ELMO and GDP/GTP exchange factor, comprising the steps of contacting ELMO, GDP/GTP exchange factor and a test substance, and then estimating the level of formation of association of ELMO and GDP/GTP exchange factor. 
     
     
         14 . A method for screening a substance interfering in the association of ELMO and GDP/GTP exchange factor, comprising the steps of contacting N terminus domain of ELMO, GDP/GTP exchange factor and a test substance, and then estimating the level of formation of association of N terminus domain of ELMO and GDP/GTP exchange factor. 
     
     
         15 . The method for screening a substance interfering in the association of ELMO and GDP/GTP exchange factor according to  claim 13 , wherein ELMO or its N terminus domain and/or GDP/GTP exchange factor is fused with another peptide. 
     
     
         16 . The method for screening a substance interfering in the association of ELMO and GDP/GTP exchange factor according to  claim 13 , wherein an antibody against ELMO or its N terminus domain is acted to a GDP/GTP exchange factor fractionated by an antibody against GDP/GTP exchange factor or by an antibody against another peptide fused with GDP/GTP exchange factor, and the level of formation of association is estimated. 
     
     
         17 . The method for screening a substance interfering in the association of ELMO and GDP/GTP exchange factor according to  claim 13 , wherein the level of formation of association is estimated by detecting GTP-binding form of activated-Rac. 
     
     
         18 . The method for screening a substance interfering in the association of ELMO and GDP/GTP exchange factor according to  claim 13 , wherein the substance interfering in the association of ELMO and GDP/GTP exchange factor is a substance promoting or suppressing the function of regulating lymphocyte migration. 
     
     
         19 . The method for screening a substance interfering in the association of ELMO and GDP/GTP exchange factor according to  claim 13 , wherein the substance interfering in the association of ELMO and GDP/GTP exchange factor is a substance inhibiting the binding of ELMO and GDP/GTP exchange factor. 
     
     
         20 . The method for screening a substance interfering in the association of ELMO and GDP/GTP exchange factor according to  claim 13 , wherein ELMO is an ELMO bound with DOCK2. 
     
     
         21 . The method for screening a substance interfering in the association of ELMO and GDP/GTP exchange factor according to  claim 13 , wherein ELMO is ELMO1. 
     
     
         22 . The method for screening a substance interfering in the association of ELMO and GDP/GTP exchange factor according to  claim 13 , wherein the GDP/GTP exchange factor is a Rac-specific GDP/GTP exchange factor. 
     
     
         23 . The method for screening a substance interfering in the association of ELMO and GDP/GTP exchange factor according to  claim 22 , wherein the Rac-specific GDP/GTP exchange factor is Tiam1. 
     
     
         24 . A method for searching a therapeutic agent for immune related diseases such as allergy, autoimmune diseases, GvH, and graft rejection, wherein the method for screening a substance interfering in the association of ELMO and GDP/GTP exchange factor according to  claim 13  is used. 
     
     
         25 . A method for searching a therapeutic agent for diseases caused by the suppression of lymphocyte migration, which promotes cytoskeletal reorganization by activating Rac, wherein the method for screening a substance interfering in the association of ELMO and GDP/GTP exchange factor according to  claim 13  is used. 
     
     
         26 - 39 . (canceled)