STAGE-SPECIFIC CHANGES IN PROTEIN-PHOSPHORYLATION DURING SPORE GERMINATION IN DICTYOSTELIUM - ROLE OF CALMODULIN

Extensive protein phosphorylation occurs during all phases of spore ge rmination in Dictyostelium discoideum. The developmental changes were prevented when germination was inhibited by inhibitors of calmodulin f unction. In addition, differences in patterns of phosphorylation were detected based upon the method of spore activation. Several phosphopro teins were lost in heat activated as compared to autoactivated spores. In spite of the fact that several aspects (i.e. autoactivation, emerg ence) are calmodulin-dependent, there was no evidence that calcium- or calmodulin-dependent protein kinase activity is present during any ph ase of spore germination. This suggests that other CaM-dependent proce sses mediate the diverse aspects of spore germination in D. discoideum . (C) 1994 Academic Press, Inc.