Cyclic GMP is rapidly formed a few seconds after binding of chemotactic signalling molecules to specific receptors on the cell surface of Dictyostelium amoebae. This phenomenon could be mimicked by addition of a pulse of Ca(2+) to permeabilised amoebae. The concentration of Ca(2+) for half-maximal response was 60 muM. Other ions (K(+), Na(+), Mg(2+) or Mn(2+)) had no effect. A pulse of 5 muM IP(3) produced a cyclic GMP response of similar magnitude but IP(2) elicited no response. The data provide strong support for the hypothe sis that cell surface receptor binding induces cyclic GMP formation by liberating Ca(2+) from internal stores. (Dictyostelium)cyclic GMPChemotaxisCa(2+).
Calcium induces cyclic GMP formation in Dictyostelium. Publishing Authors By Initials
