Quisqualate-stimulated phosphatidylinositol breakdown in rat cerebellar membranes
| Autor: | Silvia Llahi, Enrique Claro, John N. Fain |
|---|---|
| Rok vydání: | 1992 |
| Předmět: |
Phosphatidylinositol 4
5-Diphosphate GTP' G protein Guanosine AMPA receptor Biology Phosphatidylinositols Biochemistry Cellular and Molecular Neuroscience chemistry.chemical_compound Cerebellum Animals Magnesium Phosphatidylinositol Excitatory Amino Acid Agonist Amino Acids Membranes Phospholipase C Dose-Response Relationship Drug Hydrolysis Glutamate receptor Quisqualic Acid Rats Inbred Strains Rats chemistry Guanosine 5'-O-(3-Thiotriphosphate) Type C Phospholipases |
| Zdroj: | Journal of neurochemistry. 58(2) |
| ISSN: | 0022-3042 |
| Popis: | The effect of quisqualate, an excitatory amino acid agonist, on the breakdown of exogenously added phosphatidylinositol was investigated in a membrane preparation from the cerebellum of young rats. Quisqualate stimulated phospholipase C activity in a dose-dependent manner in the presence of guanosine 5'-O-(3-thiotriphosphate) (GTP gamma S). Half-maximal activation of the quisqualate response required 0.15 microM GTP gamma S and was optimal at a free Ca2+ concentration of 300 nM. Phosphoinositide breakdown was also stimulated by quisqualate using either exogenous phosphatidylinositides 4,5-bisphosphate or endogenous labeled phosphoinositides as the substrate for phospholipase C in cerebellar membranes. In the presence of guanine nucleotides, other excitatory amino acid agonists, such as L-glutamate, trans-D,L-1-aminocyclopentyl-1,3-dicarboxylic acid, and ibotenate, but not N-methyl-D-aspartate, stimulated phosphatidylinositol breakdown. However, quisqualate displayed the highest response among these excitatory amino acid agonists. These data indicate that there is a direct activation of phosphoinositide-specific phospholipase C by excitatory amino acids through a process dependent on the presence of guanine nucleotides. |
| Databáze: | OpenAIRE |
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