PKA activity assay
Haemocytes were lysed in cold PKA extraction buffer containing 25 mM Tris-HCl pH 7.4, 0.5 mM EDTA, 0.5 mM EGTA, 10 mM β-mercaptoethanol and 50-fold diluted proteinase inhibitor cocktail. Supernatants were assayed for PKA activity using the non-radioactive PepTag PKA assay kit with dye-labeled Kemptide as a substrate according to manufacturer's protocol. Results were normalized to the total protein content and expressed as fold change vs control.