Phosphorylation of Chemoattractant Receptors Is Not Essential for Chemotaxis or Termination of G-protein-mediated Responses

Ji-Yun Kim, Ron D. M. Soede, Pauline Schaap, Romi Valkema, Jane A. Borleis, Peter J. M. Van Haastert, Peter N. Devreotes, Dale Hereld
1997 Journal of Biological Chemistry  
In several G-protein-coupled signaling systems, ligandinduced receptor phosphorylation by specific kinases is suggested to lead to desensitization via mechanisms including receptor/G-protein uncoupling, receptor internalization, and receptor down-regulation. We report here that elimination of phosphorylation of a chemoattractant receptor of Dictyostelium, either by site-directed substitution of the serines or by truncation of the C-terminal cytoplasmic domain, completely prevented
more » ... d loss of ligand binding but did not impair the adaptation of several receptor-mediated responses including the activation of adenylyl and guanylyl cyclases and actin polymerization. In addition, the phosphorylation-deficient receptors were capable of mediating chemotaxis, aggregation, and differentiation. We propose that for chemoattractant receptors agonistinduced phosphorylation regulates surface binding activity but other phosphorylation-independent mechanisms mediate response adaptation.
doi:10.1074/jbc.272.43.27313 pmid:9341180 fatcat:kgxwq4ab5vcu3he3qpiv4yuzfy