Search bioRxiv⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.1101/2024.01.25.577160

Mdivi-1 affects neuronal activity by inhibition of Complex I and respiratory supercomplex assembly

Marx, N.·Ritter, N.·Disse, P.·Seebohm, G.·Busch, K. B.
View original source ↗Export metadata ↓

Abstract

Several human diseases, including cancer and neurodegeneration, are associated with excessive mitochondrial fragmentation. In this context, mitochondrial division inhibitor (Mdivi-1) has been tested as a therapeutic to block the fission-related protein dynamin-like protein-1 (Drp1). Recent studies suggest that Mdivi-1 interferes with mitochondrial bioenergetics. Here we show that the molecular mechanism of Mdivi-1 is based on inhibition of complex I at the IQ site. This leads to the destabilization of complex I, impairs the assembly of N- and Q-respirasomes and is associated with increased ROS production. The result is a reduced efficiency of ATP generation. Second, the calcium homeostasis of cells is impaired, which severely affects the electrical activity of neurons. Given the results presented here, a potential therapeutic application of Mdivi-1 is challenging because of its impact on synaptic activity. Similar to the Complex I inhibitor rotenone, Mdivi-1 may lead to neurodegenerative effects in the long term. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=114 SRC="FIGDIR/small/577160v1_ufig1.gif" ALT="Figure 1"> View larger version (26K): org.highwire.dtl.DTLVardef@1bffc82org.highwire.dtl.DTLVardef@15ae3b5org.highwire.dtl.DTLVardef@1ba3a5org.highwire.dtl.DTLVardef@94cfc0_HPS_FORMAT_FIGEXP M_FIG C_FIG O_LIMdivi-1 inhibits respiratory complex I at the IQ-site C_LIO_LIInhibition destabilizes complex I and reduces supercomplex formation C_LIO_LIMitochondrial ATP levels decrease C_LIO_LICa2+ metabolism is affected C_LIO_LINeuronal activity is compromised C_LI

Explore related subjects

cell biologyPreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Marx, N., Ritter, N., Disse, P., Seebohm, G., Busch, K. B.. 2024-01-26. Mdivi-1 affects neuronal activity by inhibition of Complex I and respiratory supercomplex assembly. https://doi.org/10.1101/2024.01.25.577160

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

Sequence context and partner availability specify divergent cell fates from a single transcription factor

Transcription factors drive the gene regulatory networks that control developmental transitions, yet which of their many targets a cell uses remains unresolved. Expressing Cebp, Cebp{beta} or Cebp{delta} identically, alone or with Oct4, Sox2, Klf4 and cMyc, gave four outcomes: adipocyte from fibroblasts and neural stem cells, trophectoderm from embryonic stem cells, and myeloid from B cells. Raising Cebp levels changed how many sites it reached, not which sequence it read: clustered motifs maintained somatic enhancers, while spillover onto low-copy sites created de novo enhancers carrying composites of Cebp and cell-type-restricted partners. In fibroblasts, Cebp also redistributed Oct4, Sox2 and Klf4 from early targets, blocking iPSC formation. Supplying the predicted partners rewrote the output: Spi1 redirected Cebp into parallel adipogenic and myeloid programs, via a transient PpargCD45 state using separate enhancers for each; TFAP2C abolished adipogenic conversion. Motif density and partner composites therefore assemble a factor's instructive output in the receiving cell.

cell biology↗
bioRxiv2026

Tracking the conformational dynamics of single molecules in live cells; GTPase cycling in Cdc42 gradients and microclusters

The Rho family of GTPases play a critical role in many cellular processes by acting as molecular switches relying on conformational changes to transition between active and inactive states. The spatial distribution and kinetics of these conformational changes are complex and vary across the cell. We describe here biosensors based on environment-responsive fluorescent dyes, capable of reporting the conformational changes of individual GTPase molecules as they traffic within living cells (SPARC Cdc42 and SPARC Rac1, 'Single Particle Activation Reporter Constructs'). We use SPARC Cdc42 to determine the rates of different steps in GTPase regulation, activation/inactivation and membrane insertion, that together generate localized gradients of Cdc42 activity driving cell motility. The biosensors also revealed heterogeneously distributed clusters of Cdc42, the mechanisms of their activation, and potential roles in polarized motility.

cell biology↗
bioRxiv2026

High-content screening identifies FDA-approved activators of mitophagy

Mitochondrial diseases are highly heterogeneous disorders caused by defects in oxidative phosphorylation, for which only limited therapeutic options are available. The elimination of dysfunctional mitochondria via mitophagy activation is an attractive strategy to treat several mitochondrial diseases, irrespective of the underlying genetic defect. To identify pharmacological activators of this pathway, we performed a high-content screening of 1,971 FDA-approved compounds using cellular reporters of TFEB nuclear translocation and mitophagy. This screening identified 294 compounds that promoted TFEB translocation, nine of which increased the number of mitolysosomes without compromising cell viability or damaging mitochondria. Among the selected compounds, Meptazinol and Ponatinib emerged as the top-ranked mitophagy inducers in fibroblasts from patients with complex I and IV deficiency, respectively, and were prioritised for further characterisation. However, they did not rescue the bioenergetic defect, suggesting that the stimulation of mitophagy per se is not sufficient to ameliorate the OXPHOS defect in mitochondrial diseases. Overall, our findings establish a scalable platform for the identification of pharmacological activators of TFEB and identify candidate compounds for therapeutic modulation of mitophagy.

cell biology↗