title: Calcium/ganglioside-dependent protein kinase activity in rat brain membrane.
abstract: The effects of gangliosides on phosphorylation were studied in rat brain membrane. Gangliosides stimulated phosphorylation only in the presence of Ca2+ with major phosphoproteins of 45,000, 50,000, 60,000, and 80,000 daltons and high-molecular-weight species. In addition, gangliosides inhibited the phosphorylation of three proteins with molecular weights of 15,000, 20,000, and 78,000 daltons. The two low-molecular-weight proteins comigrated with rat myelin basic proteins. Ganglioside stimulation was dependent on the formation of a Ca2+-ganglioside complex since the calcium salt of gangliosides stimulated phosphorylation maximally. Disialo and trisialo gangliosides were more potent stimulators of kinase activity than the monosialo GM1 X GD1a was the most potent activator tested. Asialo-GM1, cerebroside, sialic acid, neuraminyllactose, sulfatide, and the acidic phospholipids phosphatidylserine and phosphatidylinositol did not stimulate kinase activity. The Ca2+-dependent, ganglioside-stimulated phosphorylation was qualitatively similar to the pattern for calmodulin-dependent phosphorylation. However, while calmodulin-dependent kinase activity was inhibited with an IC50 of 10 microM trifluoperazine, ganglioside-stimulated kinase was inhibited with an IC50 of 200 microM trifluoperazine. These results indicate that gangliosides have complex effects on membrane-associated kinase activities and suggest that Ca2+-ganglioside complexes are potent stimulators of membrane kinase activity.
authors.forename: J R
authors.initials: JR
authors.lastname: Goldenring
authors.forename: L C
authors.initials: LC
authors.lastname: Otis
authors.forename: R K
authors.initials: RK
authors.lastname: Yu
authors.forename: R J
authors.initials: RJ
authors.lastname: DeLorenzo
mesh_terms: D000818:Animals; D001921:Brain / Q000201:enzymology*; D002118:Calcium / Q000494:pharmacology*; D002147:Calmodulin / Q000494:pharmacology; D002462:Cell Membrane / Q000201:enzymology; D005677:G(M1) Ganglioside / Q000494:pharmacology; D005732:Gangliosides / Q000494:pharmacology*; D008565:Membrane Proteins / Q000378:metabolism; D008970:Molecular Weight; D004676:Myelin Basic Protein / Q000378:metabolism; D010750:Phosphoproteins / Q000378:metabolism*; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism*; D051381:Rats
chemical_list: D002147:Calmodulin; D005732:Gangliosides; D008565:Membrane Proteins; D004676:Myelin Basic Protein; D010750:Phosphoproteins; C033851:ganglioside, GD1b; D005677:G(M1) Ganglioside; C016481:trisialoganglioside GT1; D011494:Protein Kinases; D002118:Calcium