In vivo receptor-mediated phosphorylation of a G protein in Dictyostelium.
Extracellular adenosine 3',5'-monophosphate (cAMP) serves multiple roles in Dictyostelium development, acting as a chemoattractant, a cell-cell signaling molecule, and an inducer of differentiation. The Dictyostelium G-protein alpha subunit G alpha 2 appears to be the major transducer linking the surface cAMP receptor to these intracellular responses. On stimulation of cells with cAMP, G alpha 2 is phosphorylated on one or more serine residues, resulting in an alteration of its electrophoretic mobility. Phosphorylation of G alpha 2 is triggered by increased occupancy of the surface cAMP receptor and is rapid and transient, coinciding with the time course of activation of physiological responses.
Gundersen
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Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205.
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D002462:Cell Membrane / Q000378:metabolism; D004023:Dictyostelium / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000302:isolation & purification / Q000378:metabolism*; D046911:Macromolecular Substances; D010710:Phosphates / Q000378:metabolism; D010761:Phosphorus Radioisotopes; D010766:Phosphorylation; D010768:Phosphoserine / Q000032:analysis; D011953:Receptors, Cyclic AMP / Q000378:metabolism*
D046911:Macromolecular Substances; D010710:Phosphates; D010761:Phosphorus Radioisotopes; D011953:Receptors, Cyclic AMP; D010768:Phosphoserine; D019204:GTP-Binding Proteins