Receptor G‐Protein Interactions in the Development of Dictyostelium

Academic Article

Abstract

  • Development in Dictyostelium results in the production of a multicellular aggregate. Aggregation depends on chemotaxis to cAMP and cell‐to‐cell relay of cAMP signalling. The cAMP signalling response involves surface receptor‐mediated GTP‐dependent activation of adenylate cyclase. Studies of the mutant synag 7 indicate that a soluble protein may be involved in this activation. Wild‐type supernatants are required to restore GTP‐dependent adenylate cyclase activity to mutant lysates. The surface cAMP receptor which initiates this response and is implicated in chemotaxis has been purified and an antiserum raised. The receptor undergoes a ligand‐induced mobility change, probably due to serine phosphorylation, when analyzed by SDS‐PAGE. Modulation of this transition is correlated with adaptation of the cells. Analysis of cells at various stages of development indicate that the receptor is most rapidly synthesized in the preaggregation stage. The antiserum was used to clone the cDNA for the receptor. Clones that have been sequenced account for about 33 000 D of the 37 000 D receptor. Hydropathy plots reveal 3 (or 4) potential membrane spanning domains; unsequenced regions are large enough to encode an additional 4 membrane spanning regions. Comparison to bovine rhodopsin reveals homology in those regions elucidated so far. Thirteen potential phosphorylation sites are present in the cytoplasmic domain and may be involved in ligand‐induced phosphorylation. 1988 Deutsche Botanische Gesellschaft/German Botanical Society
  • Authors

    Digital Object Identifier (doi)

    Author List

  • Lilly P; Klein P; Theibert A; Vaughan R; Pupillo M; Saxe K; Kimmel A; Devreotes PN
  • Start Page

  • 123
  • End Page

  • 127
  • Volume

  • 101
  • Issue

  • 2