Functional Properties of Ca2+-Inhibitable Type 5 and Type 6 Adenylyl Cyclases and Role of Ca2+ Increase in the Inhibition of Intracellular cAMP Content
| Autor: | Martine Imbert-Teboul, Jean-Marc Elalouf, Danielle Chabardès |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
Intracellular Fluid
chemistry.chemical_classification Calcium metabolism Gene isoform Cell type Forskolin Cell Biology Adenylyl Cyclase Inhibitors Cell biology Isoenzymes Adenylyl cyclase chemistry.chemical_compound Enzyme chemistry Biochemistry Cyclic AMP Animals Humans Calcium Intracellular Adenylyl Cyclases |
| Zdroj: | Cellular Signalling. 11:651-663 |
| ISSN: | 0898-6568 |
| DOI: | 10.1016/s0898-6568(99)00031-5 |
| Popis: | Among the different adenylyl cyclase (AC) isoforms, type 5 and type 6 constitute a subfamily which has the remarkable property of being inhibited by submicromolar Ca2+ concentrations in addition to Galphai-mediated processes. These independent and cumulative negative regulations are associated to a low basal enzymatic activity which can be strongly activated by Galphas-mediated interactions or forskolin. These properties ensure possible wide changes of cAMP synthesis. Regulation of cAMP synthesis by Ca2+ was studied in cultured or native cells which express naturally type 5 and/or type 6 AC, including well-defined renal epithelial cells. The results underline two characteristics of the inhibition due to agonist-elicited increase of intracellular Ca2+: i) Ca2+ rises achieved through capacitive Ca2+ entry or intracellular Ca2+ release can inhibit AC to a similar extent; and ii) in a same cell type, different agonists inducing similar overall Ca2+ rises elicit a variable inhibition of AC activity. The results suggest that a high efficiency of AC regulation by Ca2+ is linked to a requisite close localization of AC enzyme and Ca2+ rises. |
| Databáze: | OpenAIRE |
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