Coactosin-like protein (COTL1) is one of the numerous actin-binding proteins which regulate the actin cytoskeleton. COTL1 binds F-actin, it also interacts with 5-lipoxygenase, which is the first committed enzyme in leukotriene biosynthesis. COTL1 binds to F-actin in a calcium-independent way and has no direct effect on actin depolymerization.