MI 14 is a selective PI4KIIIβ inhibitor for antiviral research

**Background**

Phosphatidylinositol 4-kinases (PI4Ks) play a critical role in the synthesis of phosphatidylinositol 4-phosphate (PI4P), a key phospholipid involved in various cellular processes, including vesicle trafficking and signal transduction. Among the PI4K family, PI4KIIIβ is particularly significant as it is often hijacked by various viruses to create replication organelles, which are essential for the viral life cycle. Consequently, the selective inhibition of PI4KIIIβ has emerged as a promising strategy for developing broad-spectrum antiviral therapies. By disrupting the formation of these replication complexes, researchers can effectively suppress viral proliferation. In this context, we will introduce a selective PI4KIIIβ inhibitor – MI 14.

**Definition**

MI 14 is a selective PI4KIIIβ inhibitor with an IC50 value of 54 nM. According to the MI 14 description, it exhibits high selectivity, with IC50 values exceeding 100 μM for both PI4KIIIα and PI4KIIα.

**In Vitro Studies**

The MI 14 biological activity has been extensively evaluated across multiple viral models and cell lines. In vitro studies conducted in HeLa cells demonstrated that MI 14 (compound 36t) possesses potent antiviral activity against several viruses. Specifically, it showed an EC50 of 0.087 µM against HCV 1b, 0.145 µM against CVB3, 1.03 µM against HRVM, and 10.6 µM against HVC 2a. Furthermore, MI 14 in vitro testing revealed that the compound does not inhibit phosphatidylinositol 3-kinases (including PI3Ka, PI3Kb, PI3Kd, and PI3Kg) with IC50 values up to 10 µM, highlighting its specificity for the PI4KIIIβ isoform. Regarding safety and toxicity, the CC50 of MI 14 against human HeLa cells was found to be greater than 50 μM, indicating a favorable therapeutic window. In conclusion, MI 14 is a highly selective and potent PI4KIIIβ inhibitor with significant potential for antiviral research.

Keywords

MI 14, 1715934-43-2, MI14, MI-14, PI4K, HCV, Phosphatidylinositol 4 kinases, PI4 kinases, Hepatitis C virus, Antiviral, HCV 1b, CVB3, HRVM, HVC 2a, Inhibitor

References

[1] Ivana Mejdrová, et al. Highly Selective Phosphatidylinositol 4-Kinase IIIβ Inhibitors and Structural Insight into Their Mode of Action. J Med Chem. 2015 May 14;58(9):3767-93.