Calcium ionophore
Ionomycin is a Calcium ionophore and an antibiotic produced by Streptomyces conglobatus . Addition of 2 μM Ionomycin to LCLC 103H cells causes an instantaneous increase in intracellular Ca 2+ concentration from 50 to 180 nM. DNA and protein analysis in Ionomycin-treated cultures revealed DNA fragmentation and PARP cleavage to an 85-kDa fragment typical of caspase-mediated apoptosis. Necrosis could be detected in ~1-5% of the Ionomycin treated cells. Caspase activation in whole cells was followed by monitoring the increase in activity against Ac-DEVD-amc following Ionomycin treatment. Ionomycin-mediated cleavage and exosome release. Following Ionomycin exposure, medium conditioned by SKOV3ip cells had increased amounts of exosomes containing the L1-32 cleavage fragment.