Cyclic AMP-dependent in tritVo Activation of Trehalase from Dormant Phycomyces blakesleeanus Spores

Summary: The activity of trehalase in a crude extract of dormant Phycomyces blakesleeanus spores increased 10- to 20-fold during incubation in the presence of cyclic AMP and ATP. A phosphorylation of the enzyme was probably involved, as a more pronounced activation was obtained when cyclic AMP was replaced by the catalytic subunit of beef heart protein kinase. The γ-thio derivative of ATP could replace ATP in the activation but was quantitatively less effective. The effective concentrations of cyclic AMP and ATP were comparable to their likely intracellular concentrations; thus phosphorylation could be the in vivo mechanism of trehalase activation during the activation of dormant spores by heat or acetate.