Unified control of chemotaxis and cAMP mediated cGMP accumulation by cAMP in dictyostelium discoideum

Abstract

Summary Guanosine 3′5′ cyclic monophosphate (cGMP) accumulation in response to adenosine 3′5′ cyclic monophosphate (cAMP) in the aggregateless Dictyostelium discoideum mutant, Agip 55, has been investigated in view of cGMP's proposed role during chemotaxis. This mutant was deficient in chemotaxis to cAMP and also showed a deficient cGMP accumulation in response to this attractant. A deficient chemotactic response can be reverted in Agip 55 cells into a normal chemotactic response by pulsating with cAMP. cAMP pulsated cells showed a higher cAMP binding capacity and also gave a normal cGMP accumulation in response to cAMP. Therefore it is concluded that the same cAMP receptor controls chemotaxis and cGMP accumulation. These results show also that cAMP controls the development of cAMP receptors and cAMP mediated cGMP accumulation and that the chemotactic response involves changes in the cGMP levels.