PKM and colitis: For instance, succinylation of the K311 site plays an important role in regulating the enzymatic activity of PKM2, while SIRT5 desuccinylation and activation of PKM2 play a vital role in the regulation of macrophage metabolism in colitis and colon cancer.[43] After glucose starvation, lysine succinylation at position 433 of PKM2 increased the migration of PKM2 to the mitochondria and enhanced its interaction with mitochondrial outer membrane voltage-dependent anion channels (VDAC3) in human colon cancer cells.