Stimulation of cyclic adenosine 3',5'-monophosphate-dependent protein kinase with brain gangliosides
| Autor: | Hitoshi Okamura, Mei Satake, Eishichi Miyamoto, Futoshi Arakane, Kohji Fukunaga, Kohji Miyazaki |
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| Rok vydání: | 1995 |
| Předmět: |
Brain Chemistry
Synapsin I Kinase Protein subunit Cell Biology Biology Mitogen-activated protein kinase kinase Cyclic AMP-Dependent Protein Kinases Catalysis Chromatography DEAE-Cellulose Stimulation Chemical Rats Substrate Specificity Enzyme Activation Cellular and Molecular Neuroscience Biochemistry Ca2+/calmodulin-dependent protein kinase Gangliosides Aplysia Cyclic AMP Animals Kinase activity Glycolipids Protein kinase A Protein kinase C |
| Zdroj: | Neurochemistry international. 26(2) |
| ISSN: | 0197-0186 |
| Popis: | The holoenzyme of cAMP-dependent protein kinase (cAMP-kinase) partially purified from the particulate fraction of rat brain was stimulated by gangliosides. Among various gangliosides tested, GM1 was most potent, giving Ka value of 19.5 microM. The maximal activation of the kinase was obtained with 100 microM GM1 using kemptide as substrate. Gangliosides inhibited the kinase activity of the catalytic subunit of cAMP-kinase. Of various substrates tested, the ganglioside-stimulated cAMP-kinase could phosphorylate microtubule-associated protein 2, synapsin I and myelin basic protein, but not histone H1 and casein. The molecular mechanisms of the stimulatory effect of gangliosides were investigated. The kinase activated with GM1 was inhibited by the addition of PKItide, a specific inhibitor for cAMP-kinase. However, GM1 did not dissociate the holoenzyme into the catalytic and regulatory subunits and did not interfere with the binding ability of cAMP to the holoenzyme. These results suggest that the gangliosides can directly activate cAMP-kinase in a different manner from cAMP. |
| Databáze: | OpenAIRE |
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