âThatâs something we can test. If it does, caspase-1 inhibitors mightâand I emphasize mightâbecome a component of a curative cocktail.â G. Doitsh et al., âCell death by pyroptosis drives CD4 T-cell depletion in HIV-1 infection,â Nature, doi:10.1038/nature12940, 2013.
Decades ago it was believed that a cascade of enzymes controls the activity of HMG-CoA reductase: an HMG-CoA reductase kinase was thought to inactivate the enzyme, and the kinase in turn was held to be activated via phosphorylation by HMG-CoA reductase kinase kinase.
Two processes convert ADP into ATP: 1) substrate-level phosphorylation; and 2) chemiosmosis. Substrate-level phosphorylation occurs in the cytoplasm when an enzyme attaches a third phosphate to the ADP (both ADP and the phosphates are the substrates on which the enzyme acts). This is illustrated in Figure 3. Figure 3. Enzymes and the formation of NADH and ATP.