Open AccessShort-Term Binding and Hydrolysis of Cyclic 3′:5′-Adenosine Monophosphate by Aggregating Dictyostelium Cells
Author(s) -
Dieter Malchow,
Günther Gerisch
Publication year - 1974
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.71.6.2423
Subject(s) - dictyostelium discoideum , phosphodiesterase , adenosine , dictyostelium , chemotaxis , biochemistry , chemistry , kinetics , receptor , cyclic nucleotide phosphodiesterase , biophysics , biology , enzyme , physics , quantum mechanics , gene
Transient binding of cyclic AMP to aggregating cells ofDictyostelium discoideum was measured under cyclic GMP excess in order to inhibit cyclic AMP hydrolysis by cell-bound phosphodiesterase. Cyclic GMP extended the period of half-maximal cyclic AMP binding from less than 5 sec to 1-2 min. With the same time course as bound cyclic AMP was released from the cells, labeled 5′-AMP appeared in the medium. Specificity, kinetics, and developmental regulation suggest that the cyclic AMP-binding sites exposed in living cells are identical with receptor sites for the chemotactic response. The functioning of the cyclic AMP-receptor/phosphodiesterase system and its formal similarity with the synaptic acetylcholine-receptor/esterase system are discussed.