Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
ADP + H2O | Solanum tuberosum | - |
AMP + phosphate | - |
? | |
ATP + 2 H2O | Solanum tuberosum | overall reaction | AMP + 2 phosphate | - |
? | |
ATP + H2O | Solanum tuberosum | - |
ADP + phosphate | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Solanum tuberosum | - |
- |
- |
Source Tissue | Comment | Organism | Textmining |
---|---|---|---|
commercial preparation | - |
Solanum tuberosum | - |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
ADP + H2O | - |
Solanum tuberosum | AMP + phosphate | - |
? | |
ATP + 2 H2O | overall reaction | Solanum tuberosum | AMP + 2 phosphate | - |
? | |
ATP + H2O | - |
Solanum tuberosum | ADP + phosphate | - |
? |
Synonyms | Comment | Organism |
---|---|---|
ecto-ATPase | - |
Solanum tuberosum |
NTPDase1/CD39 | - |
Solanum tuberosum |
General Information | Comment | Organism |
---|---|---|
physiological function | apyrase decreases microglial ramification and surveillance. Applying the ATPase apyrase, an enzyme which hydrolyzes ATP and ADP, reduces microglial process ramification and surveillance in acutely prepared postnatal day (P)12 rat hippocampal slices, suggesting that ambient ATP/ADP maintains microglial surveillance. But attempting to raise the level of ATP/ADP by blocking the endogenous ecto-ATPase (termed NTPDase1/CD39), which also hydrolyzes ATP/ADP, does not affect the cells' ramification or surveillance, nor their membrane currents, which respond to even small rises of extracellular [ATP] or [ADP] with the activation of K+ channels. This indicates a lack of detectable ambient ATP/ADP and ecto-ATPase activity, contradicting the results with apyrase. Contamination of commercially available apyrase by a high K+ concentration reduces ramification and surveillance by depolarizing microglia. Exposure to the same K+ concentration (without apyrase added) reduced ramification and surveillance as with apyrase. Dialysis of apyrase to remove K+ retains its ATP-hydrolyzing activity but abolishes the microglial depolarization and decrease of ramification produced by the undialyzed enzyme. Microglia are very sensitive to increases of extracellular ATP concentration, to which they respond by activating P2Y12 receptor-gated THIK-1 K+ channels, generating an outward K+ current which leads to a hyperpolarization of their membrane | Solanum tuberosum |