There are 21 genes coding for different types of Cxs, but despite this heterogeneity, all Cxs share a common topology, including N- and C-termini located in the cytoplasmic side, four transmembrane domains (TM1-4), one intracellular loop (IL-1), and two extracellular loops (EL1-2).

Both hemichannels and GJCs have been shown to play important physiological roles, and their dysfunction is associated with several pathologies. While hemichannels are formed by the docking of six Cx-subunits and allow the flux of molecules and ions between the cytoplasm, the extracellular media, and vice versa, GJCs allow the exchange of molecules and ions between the cytoplasm of neighboring cells. Results: These results demonstrate that KI04 could be used as a Cx46 inhibitor and could help to develop future selective Cx46 inhibitors.Ĭonnexins (Cxs) are a family of proteins located mostly at the plasma membrane, where they form two types of channels: hemichannels and gap junction channels (GJCs). MD analysis revealed two putative binding sites of KI04 in the Cx46 hemichannel. Interestingly, 5 mM DTT did not reverse KI04 inhibition, but the KI04 effect completely disappeared after washing out KI04 from the recording media. The inhibitory effect was not associated with changes in Cx46 electrophoretic mobility or its intracellular localization. Results: We observed that kanamycin and KI04 were the most potent inhibitors of Cx46 hemichannels among several aminoglycosides, presenting an IC 50 close to 10 μM. Methods: We transfected HeLa cells with the human Cx46tGFP and characterized the effect of a kanamycin-derived molecule (KI04) on Cx46 hemichannel activity by time-lapse recordings, changes in phosphorylation by Western blot, localization by epifluorescence, and possible binding sites by molecular dynamics (MD). Therefore, our main goal is to test whether these molecules have similar effects in mammalian cells. However, these studies have been performed in E. In the last decade, some molecules derived from aminoglycosides have been developed as inhibitors of Cxs hemichannels. Despite their importance in several human physiological and pathological conditions, their pharmacology is very poor. Background: Connexins (Cxs) are proteins that help cells to communicate with the extracellular media and with the cytoplasm of neighboring cells.

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