Tea catechin, epigallocatechin-3-gallate suppresses myosin II regulatory light chain phosphorylation

Phosphorylation of myosin II regulatory light chain (MRLC) is critical event for many cellular processes including muscle contraction, mytosis, migration, and exocytosis. Epigallocatechin-3-O-gallate (EGCG) is a major polyphenolic compound of green tea and has various physiological functions. We found that EGCG disrupted stress fibers and suppressed the MRLC phosphorylation in HeLa cells. To elucidate the mechanism for the suppressive effect on the phosphorylation, we examined the effect of various inhibitors for kinases that modulate MRLC phosphorylation. None of the inhibitors mimic the activity of EGCG. These results suggest that EGCG is a compound that can suppress MRLC phosphorylation.