Requirement of brain extract for the activity of brain calmodulin-dependent protein kinase IV expressed in Escherichia coli.
Calmodulin-dependent protein kinase IV (CaM-kinase IV) is a Ca(2+)-responsive multifunctional protein kinase which occurs abundantly in the brain. When cDNA for rat brain CaM-kinase IV was expressed in Escherichia coli, the enzyme was produced in a good yield, but it did not show significant activity. The inactive recombinant CaM-kinase IV was phosphorylated and became highly active on incubation with a rat brain extract in the presence of both Ca2+/calmodulin and ATP/Mg2+. The recombinant CaM-kinase IV-activating activity in brain was one to two orders of magnitude higher than that in the other tissues examined. These observations suggest that CaM-kinase IV may undergo a posttranslational modification, probably Ca2+/calmodulin-dependent phosphorylation by CaM-kinase IV kinase, before exhibiting activity in the central nervous system.
Okuno
S
S
Department of Biochemistry, Asahikawa Medical College, Hokkaido.
Fujisawa
H
H
D000818:Animals; D001483:Base Sequence; D001921:Brain / Q000201:enzymology*; D054734:Calcium-Calmodulin-Dependent Protein Kinase Type 4; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D004789:Enzyme Activation; D004926:Escherichia coli / Q000378:metabolism; D005260:Female; D008297:Male; D008969:Molecular Sequence Data; D010766:Phosphorylation; D011499:Protein Processing, Post-Translational; D051381:Rats; D017208:Rats, Wistar; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D014020:Tissue Extracts / Q000494:pharmacology
D018076:DNA, Complementary; D011994:Recombinant Proteins; D014020:Tissue Extracts; D054734:Calcium-Calmodulin-Dependent Protein Kinase Type 4; D017871:Calcium-Calmodulin-Dependent Protein Kinases; C517686:Camk4 protein, rat