Protein Phosphatase Inhibitor

**Semantic type:** Chemical Viewed Functionally

**Definition:** Any substance that inhibits a protein phosphatase, especially those that inhibit the serine/threonine protein phosphatases 1 and 2A, enzymes that regulate entry of the cell into the cell cycle, mitosis and apoptosis. Inhibition of protein phosphatases 1 and 2A can cause cell cycle arrest and apoptosis.