DICTYOSTELIUM DEVELOPMENT IN THE ABSENCE OF CAMP

Adenosine 3',5'-monophosphate (cAMP) and cAMP-dependent protein kinase (PKA) are regulators of development in many organisms. Dictyostelium uses cAMP as an extracellular chemoattractant and as an intracellular signal for differentiation. Cells that are mutant in adenylyl cyclase do not develop. Moderate expression of the catalytic subunit of PKA in adenylyl cyclase-null cells led to near-normal development without de tectable accumulation of cAMP. These results suggest that all intracel lular cAMP signaling is effected through PKA and that signals other th an extracellular cAMP coordinate morphogenesis in Dictyostelium.