Signal transduction during amoebal chemotaxis of Dictyostelium discoideum.

Amoebae of the cellular slime mould Dictyostelium are chemotactically responsive to pulses of cyclic AMP produced by aggregation centres. Pulses of this nucleotide bind to the cell surface cyclic AMP receptors and induce a chain of intracellular events leading to actin polymerization, formation of cyclic GMP and specific induction of gene activity. An intermediary messenger is Ca2+ liberated from internal stores by inositol trisphosphate (IP3).