title: Action of a slowly hydrolysable cyclic AMP analogue on developing cells of Dictyostelium discoideum.
abstract: Adenosine 3',5'-cyclic phosphorothioate (cAMP-S) is a cyclic AMP (cAMP) analogue which is only slowly hydrolysed by phosphodiesterases of Dictyostelium discoideum. The affinity of cAMP-S to cAMP receptors at the cell surface is only one order of magnitude lower than that of cAMP. cAMP-S can replace cAMP as a stimulant with respect to all receptor-mediated responses tested, including chemotaxis and the induction of cAMP pulses. cAMP-S does not affect growth of D. discoideum but it blocks cell aggregation at a uniform concentration of 5 x 10(-7) M in agar plate cultures of strain NC-4 as well as its axenically growing derivative, Ax-2. Another wild-type strain of D. discoideum, v-12, is able to aggregate on agar plates supplemented with 1 mM cAMP-S. The development of Polysphondylium pallidum and P. violaceum is also highly cAMP-S resistant. In Ax-2 both differentiation from the growth phase to the aggregation-competent stage and chemotaxis are cAMP-S sensitive, whereas in v-12 only chemotaxis is inhibited. v-12 can still form streams of cohering cells and fruiting bodies when chemotaxis is inhibited by cAMP-S. Whereas cAMP induces differentiation into stalk cells at concentrations of 10(-3) or 10(-4) M, cAMP-S has the same effect in strain v-12 at the much lower concentration of 10(-6) M.
mesh_terms: D002633:Chemotaxis / Q000187:drug effects; D000242:Cyclic AMP / Q000031:analogs & derivatives* / Q000494:pharmacology; D004023:Dictyostelium / Q000166:cytology / Q000187:drug effects / Q000254:growth & development*; D005110:Extracellular Space / Q000201:enzymology; D006868:Hydrolysis; D008027:Light; D009024:Morphogenesis / Q000187:drug effects; D010727:Phosphoric Diester Hydrolases / Q000378:metabolism; D011953:Receptors, Cyclic AMP / Q000187:drug effects; D012542:Scattering, Radiation
chemical_list: D011953:Receptors, Cyclic AMP; D000242:Cyclic AMP; D010727:Phosphoric Diester Hydrolases