Ionomycin (SQ23377) is a potent, selective calcium ionophore and an antibiotic produced by Streptomyces conglobatus. Ionomycin (SQ23377) is highly specific for divalent cations (Ca>Mg>Sr=Ba). Ionomycin (SQ23377) promotes apoptosis. Ionomycin also induces the activation of protein kinase C (PKC)^[1][2][3].

Calcium ionophore^[1]

Ionomycin is a Calcium ionophore and an antibiotic produced by Streptomyces conglobatus^[1].
Addition of 2 μM Ionomycin to LCLC 103H cells causes an instantaneous increase in intracellular Ca²⁺ 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^[2].
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^[4].
Ionomycin also phosphorylate p38 MAPK by Ca²⁺ influx through SOCE, leading to suppression of TNF-α-induced NF-κB phosphorylation^[5].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

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  [3]. Gil-Parrado S, et al. Ionomycin-activated calpain triggers apoptosis. A probable role for Bcl-2 family members. J Biol Chem. 2002 Jul 26;277(30):27217-26.  [Content Brief]

  [4]. Stoeck A, et al A role for exosomes in the constitutive and stimulus-induced ectodomain cleavage of L1 and CD44. Biochem J. 2006 Feb 1;393(Pt 3):609-18.  [Content Brief]

  [5]. Junsuke Uwada, et al. Store-operated calcium entry (SOCE) contributes to phosphorylation of p38 MAPK and suppression of TNF-α signalling in the intestinal epithelial cells. Cell Signal. 2019 Nov;63:109358.  [Content Brief]