| Specific inhibition of endogenous Galpha 12 and Galpha 13 , but not of Galphaq , by expression of respective C terminal peptides abolished S1P2 mediated inhibition of Rac , membrane ruffling , and migration , as well as stimulation of Rho and stress fiber formation . ^^^ Fusion receptors comprising S1P2 and either Galpha 12 or Galpha 13 , but not Galphaq , mediated S1P stimulation of Rho and also inhibition of Rac and migration . ^^^ |