Model depicting the dichotomous regulation of platelet shape change by Rho-kinase and Ca²⁺-dependent MLC-kinase. See text for details. Abbreviations: MLC-Ⓟ, phosphorylated myosin light-chain; MLC-kinase, Ca²⁺/calmodulin-dependent myosin light-chain kinase; MLC-Pase-Ⓟ, phosphorylated myosin light-chain phosphatase; PLCβ, phospholipase Cβ; PLCγ2-ⓅY, tyrosine-phosphorylated phospholipase Cγ2; Src/Syk, Src-family tyrosine kinases and tyrosine kinase Syk.