An Acanthamoeba castellanii metacaspase associates with the contractile vacuole and functions in osmoregulation

► First evidence for any metacaspase that associate with contractile vacuole (CV). Acanthamoeba metacaspase (Acmcp) is essential for the cellular osmoregulation. ► The proline-rich region play an important role for Acmcp protein function. ► Acmcp weakly interact with Calmodulin, RabD, Rab11 and the vacuolar proton ATPase. ► Acmcp protein is a candidate drug target for Acanthamoeba infection treatment.