Signal anticipation in a GPCR pathway -- Single cell measurements of scaffold recritment show rapid dose response alignement before receptor binding reaches equilibrium

ARIEL CHERNOMORETZ; ALAN BUSH; PABLO BALENZUELA; LUCIANA BRUNO; RODRIGO LAJE; TY THOMSON; ROGER BRENT; ALEJANDRO COLMAN LERNER

Hinxton, Reino Unido

Congreso; Computational Cell Biology Meeting; 2008

Cold Spring Harbor y Wellcome Trust

Cells implement precise responses to signals. We investigated in S.cerevisiae early pheromone signal propagation. Using microscope-based cytometry, we measured membrane recruitment of the scaffold protein Ste5. Ste5 is recruited in a few seconds in response to high pheromone. We found that pheromone dose information is transmitted precisely to Ste5 but that recruitment reaches plateau levels faster than pheromone:receptor complex (“signal anticipation”). Thus, the system may "measure" the rate of pheromone binding. We developed a detailed chemical reaction model describing the known biological mechanisms. This model reproduces the cells’ behavior. We are currently exploring what feature of the model is responsible for signal anticipation.