Latrunculin A

Latrunculin A is a bioactive 2-thiazolidinone macrolide derived from sponges that sequesters G-actin and prevents F-actin assembly. It binds monomeric actin with 1:1 stoichiometry and can be used to block actin polymerization both in vitro (K_d = 0,2 μM) and in cells (0,5 μM, 30 min).

Latrunculin A (1-10 μM) causes depolymerization of tumor cell cytoskeleton within ten minutes. Overnight treatment of cells with latrunculin A (10 μM) strongly suppresses actin synthesis. Prolonged cell treatment blocks dexamethasone-induced changes in actin cytoskeleton with no effect on cell viability. Actin disruption is used to study cell functions in vitro (e.g., migration, endocytosis) and in vivo (e.g., tumor cell invasion).