Fig 18. Summary of key findings.

A schematic showing the main conclusions from this study regarding serum-induced phosphorylation of the regulatory light chains of myosin II (LC₂₀) and the regulatory kinases and phosphatase involved. Serum treatment of CASMC and UASMC activates Rho-associated coiled-coil kinase (ROCK) and zipper-interacting protein kinase (ZIPK) leading to phosphorylation of the regulatory myosin-targeting subunit (MYPT1) of myosin light chain phosphatase (MLCP) at T853 and prostate apoptosis response 4 (Par4) at T163, both of which result in inhibition of MLCP activity. ZIPK activation involves phosphorylation by ROCK and autophosphorylation. Activated ROCK and ZIPK directly phosphorylate LC₂₀ at T18 and S19.