12‐O‐Tetradecanoyl phorbol‐13‐acetate interferes with germination of Phycomyces blakesleeanus sporangiospores

Abstract
The presence of protein kinase C (PKC), a key enzyme in signal transduction, has not been investigated in fungal cells. The phorbol ester TPA, an activator of PKC, may be used as an indicator of the presence and role of PKC in Phycomyces blakesleeanus spores. Activation of spore germination by acetate was prevented by 6 nM TPA. The TPA analog 4αPDD, an ineffective activator of PKC, did not affect spore germination. 3 mM dbcAMP, on the other hand, reversed the inhibition of germination caused by TPA. TPA-stimulated protein kinase activity was detected in spores. The possible relationship between PKC and the increased levels of cAMP that accompany the induction of spore germination is discussed.