Fig. 4.

PRG is predominantly activated downstream of GRPR. (A–C) Caco-2 cells were serum-starved overnight and then stimulated with GRP for indicated times. The lysates were subsequently used for RhoA^G17Apulldown, where GST-RhoA^G17A protein is used to pulldown activated RhoGEFs from total cell lysate (see Materials and Methods). Precipitates and the lysate samples were then immunoblotted for PRG, LARG, and p115RhoGEF. Shown are representative images of three independent experiments. (D) Densitometric analysis of activation states of three RH-RhoGEFs normalized to endogenous RH-RhoGEF levels and expressed as fold activation over 0-minute time-point. Shown are mean values ± S.E.M.