Fig. 7.

IL-17A signaling is correlated with enhanced expression and activation of Ras homolog gene family, member A (RhoA), Rho-associated protein kinase (ROCK), C-kinase-activated protein phosphatase-1 inhibitor (CPI-17), and Ca²⁺/calmodulin-dependent protein kinase II (CaMKII). These G protein-coupled receptor effectors regulate the phosphorylation (P) of myosin light chain, which modulates smooth muscle contraction. Enhanced contractile force of airway smooth muscle (ASM) cells is known to lead to airway obstruction through a reduced airway lumen diameter. Moreover, oxidized CaMKII (ox-CaMKII) is a product of CaMKII interaction with reactive oxygen species (ROS), which may promote airway reactivity. CICR, calcium-induced calcium release; DAG, diacylglycerol; IP₃, inositol (1,4,5)-trisphosphate; IP₃R, IP₃ receptor; MLC20, myosin regulatory light chain 20 kDa; MLCK, myosin light chain kinase; MLCP, myosin light chain phosphatase; PIP2, phosphatidylinositol 4,5-bisphosphate; RyR, ryanodine receptor.