Serine is then converted to pyruvate by serine dehydratase. These receptors are serine/threonine kinase receptors. They are protein serine/threonine kinases. GSK-3 functions by phosphorylating a serine or threonine residue on its target substrate. MITF is phosphorylated on several serine and tyrosine residues. These five are alanine, aspartic acid, asparagine, glutamic acid and serine. It contains inhibitors of multiple cysteine and serine protease families. This gene encodes a member of the RSK family of serine/threonine kinases. Phosphorylation of tau is regulated by a host of kinases, including PKN, a serine/threonine kinase. One major pathway leads to the activation of the serine/threonine kinase, Akt. Thrombin is also inactivated by antithrombin, a serine protease inhibitor. This gene encodes a protein that belongs to the serine protease family. Curcumin inhibits both by preventing phosphorylation of the serine. These modifications include&colon; methylation, acetylation and serine phosphorylation. The enzymatic mechanism is similar to that of other serine proteases.