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Bonhenry, D.

Publications and source records attributed to Bonhenry, D..

2 recordsLinked to original sources

Targeting plasma membrane and mitochondrial instability in breast cancer cells and breast epithelial to mesenchymal transition-model cells by adamantyl diaza-crown ether ZG613

The adamantane derived diaza-crown ether ZG613 was assessed as a potential breast cancer cells and breast epithelial to mesenchymal transition (EMT)-model cells targeting agent. We postulated that ZG613 activity relies on its plasma/mitochondria membrane disruption ability based on adamantane hydrophobicity and/or crown ether related ionophoric properties. We performed molecular dynamics (MD) simulations and next generation sequencing, followed by in vitro study of cell death, membrane perturbations and ionophoric ability, as well as in vivo study of effects on the tumour growth. MD simulation and RNA sequencing pointed toward physical disruption of plasma membrane by ZG613, corroborated by measured increase in membrane permeability leading to cell death. Measurements of ion fluxes confirmed ZG613 inability to transport Na+ and K+, as predicted by MD simulation. EMT-model cells exhibit changes in mitochondrial morphology and ATP levels, successfully targeted by ZG613. ZG613 caused mild retardation of tumour growth in vivo. In conclusion, ZG613 kills breast cancer cells and breast EMT-model cells by physical disruption of plasma membrane and impairments of mitochondrial functions. Breast EMT cells represent good potential targets within the breast tumour, due to their plasma membrane and mitochondrial instability.

cancer biology↗

A series of Orai1 gating checkpoints in transmembrane and cytosolic regions requires clearance for CRAC channel opening/ Clearance and synergy of Orai1 gating checkpoints controls pore opening

The initial activation step in gating of ubiquitously expressed Orai1 Calcium (Ca2+) ion channels represents the store-dependent coupling to the Ca2+ sensor protein STIM1. An array of constitutively active Orai1 mutants gave rise to the hypothesis that STIM1 mediated Orai1 pore opening is accompanied by a global conformational change of all Orai TM helices within the channel complex. Here, we prove that a local conformational change spreads omnidirectionally within the Orai1 complex. Our results demonstrate that a global, opening-permissive allosteric communication of TM helices is indispensable for pore opening and requires clearance of a series of Orai1 gating checkpoints. We discovered these gating checkpoints in middle and cytosolic extended TM domain regions. Our findings are based on a library of double point mutants that contain each one loss-of-function (LoF) with one gain-of-function (GoF) point mutation in a series of possible combinations. We demonstrated that an array of LoF mutations act dominant over most GoF mutations within the same as well as of an adjacent Orai subunit. We further established inter- and intramolecular salt-bridge interactions of Orai subunits as a core element of an opening-permissive Orai channel architecture. Collectively, clearance and synergistic action of all these gating checkpoints is required to allow STIM1 coupling and Orai1 pore opening. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=166 SRC="FIGDIR/small/207183v2_ufig1.gif" ALT="Figure 1"> View larger version (76K): org.highwire.dtl.DTLVardef@3f80f1org.highwire.dtl.DTLVardef@12a6a0aorg.highwire.dtl.DTLVardef@197b825org.highwire.dtl.DTLVardef@1bab109_HPS_FORMAT_FIGEXP M_FIG C_FIG

biophysics↗