Protein Kinases in Mitochondria of the InvertebrateArtemia franciscana

The information concerning protein kinases in animal mitochondria is scarce and related only to mammals. No data are available for invertebrates. We demonstrate here the presence of casein kinase II (CK II) and cAMP-dependent protein kinase (PKA) in the purified mitochondria of the crustaceanArtemia franciscana.Whereas the mitochondrial CK II showed the same characteristics of the cytosolic enzyme, mitochondrial PKA had an apparentKmfor its substrate Kemptide 1 order of magnitude lower than that of the cytosolic enzyme. CK II and PKA phosphorylate different sets of proteins inArtemiamitochondriain vitro.The use of an activity gel assay has allowed the detection of additional protein kinases, as yet unidentified, inArtemiamitochondria.