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.
Receptor tyrosine kinases (RTKs), which bind to peptide / protein hormones, may exist as dimers or dimerize during binding to ligands. Ligand binding leads to activation of the kinase activity of the receptor and autophosphorylation of tyrosine residues in its cytosolic domain (see Figure 20-31).The activated receptor also can phosphorylate other protein substrates.igand binding leads to activation of the kinase activity of the receptor and autophosphorylation of tyrosine residues in its cytosolic domain (see Figure 20-31). The activated receptor also can phosphorylate other protein substrates.