Mechanism of action of Mcf1 toxin. (IMAGE) Max Planck Institute of Molecular Physiology Caption After binding of the toxin to as yet unknown receptors on the surface of the host cell, the toxin is endocytosed. Acidification of the endosome triggers a conformational change inside the 600 amino acid-long delivery region, which forms a pore and translocates the head region of the toxin inside the target cell. After translocation, a series of proteolysis reactions and cleavages, Mcf1 toxic payloads are released, which impair essential physiological pathways ultimately leading to cell death. Credit MPI of Molecular Physiology Usage Restrictions The image may only be used with appropriate caption or credit. License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.