| DOCK180 and ELMO cooperate biochemically and genetically to activate Rac in several biological events. However, the role of these proteins in Rac signaling is still poorly understood. We hypothesize that DOCK180 functions as a RacGEF, with ELMO binding to DOCK180 being required for integration of proper Rac signaling rather than Rac activation per se. We postulate that ELMO acts as a subcellular targeting signal for spatio-temporal restriction of DOCK180-mediated Rac signaling and/or as a scaffold for Rac effectors to enforce cell migration.;In Aim ;We conclude that, at basal levels, ELMO/DOCK180 is complexed, with ELMO in an autoinhibited state in the cytosol. Through cell stimulation, certain GTPases will be activated that now bind the ELMO RBD and alleviate the intramolecular contacts. In this way, the GTPase anchors the activated ELMO/DOCK180 module in place for proper spatio-temporal regulation of Rac activation and signaling.;Keywords : Cell migration, DOCK180, ELMO, Rac GTPase, Arl4 GTPase, RBD. |
