Project description:Ectopic ATP synthase is a functional onco-protein increases cell proliferation when transported to plasma membrane of cancer cells. Our previous study performed large scale gene silencing screening indicated ER and mitochondrial transport pathways may lead to ectopic ATP synthase expression. Silencing dynamin-related protein 1 (Drp1), mitofusin-1 (Mfn1) and Parkin affected ectopic ATP synthases expression. However, the underlying trafficking mechanism is poorly understood. Here, we analyzed our membrane and mitochondrial proteome of lung cancer A549 cells and found that both nuclear-encoded ATP synthase subunits and mitochondrial-encoded components-ATP6 translocated to cell surface, indicating that ATP synthase subunits assembled in mitochondria. Furthermore, serum starvation enhanced ATP synthase translocation to plasma membrane, Mdivi-1, a chemical inhibitor of the mitochondrial fission protein Drp1, rescued the phenomena. Additionally, image quantification of mitochondria, showing that mitochondrial fission preference cells expressed more eATP synthase. Therefore, we proposed that eATP synthase trafficking may be related to mitochondrial dynamics. Additionally, ICC and flow cytometry revealed the expression of a critical transcription factor associated with high-risk neuroblastoma, MYCN, correlated with eATP synthase expression. To better understand whether MYCN mediated mitochondrial fission and affected ATP synthase trafficking, we first analyzed MYCN ChIP-sequencing data and found Drp1, Mfns and Parkin possessed the consensus DNA-binding motif of MYCN. Further high-resolution image analysis showed higher mitochondrial fission and eATP synthase expression in MYCN-amplified neuroblastoma. Last, silencing MYCN reduced the fission level by detecting DRP1. In summary, we suggest that trafficking of ectopic ATP synthase may via mitochondrial dynamics.
Project description:Reduction of mitochondrial membrane potential is a hallmark of mitochondrial dysfunction. It activates adaptive responses in organisms from yeast to human to rewire metabolism, remove depolarized mitochondria, and degrade unimported precursor proteins. It remains unclear how cells maintain mitochondrial membrane potential, which is critical for maintaining iron-sulfur cluster (ISC) synthesis, an indispensable function of mitochondria. Here we show that yeast oxidative phosphorylation mutants deficient in complex III, IV, V, and mtDNA respectively, have graded reduction of mitochondrial membrane potential and proliferation rates. Extensive omics analyses of these mutants show that accompanying mitochondrial membrane potential reduction, these mutants progressively activate adaptive responses, including transcriptional downregulation of ATP synthase inhibitor Inh1 and OXPHOS subunits, Puf3-mediated upregulation of import receptor Mia40 and global mitochondrial biogenesis, Snf1/AMPK-mediated upregulation of glycolysis and repression of ribosome biogenesis, and transcriptional upregulation of cytoplasmic chaperones. These adaptations disinhibit mitochondrial ATP hydrolysis, remodel mitochondrial proteome, and optimize ATP supply to mitochondria to convergently maintain mitochondrial membrane potential, ISC biosynthesis, and cell proliferation.
Project description:The goal of this analysis was to profile the gene expression signatures associated to different neuronal doses of IF1. The mitochondrial ATP synthase produces ATP by oxidative phosphorylation and integrates different signals to regulate cellular functions and fate. The ATPase inhibitory factor 1 (IF1) is a structurally-disordered protein that inhibits the ATP synthase, contributing to metabolic reprogramming and signalling through mitochondrial reactive oxygen species (mtROS). mtROS regulate kinases and transcription factors in mitohormetic responses that favour adaptation to toxic insults. IF1 is tissue-specifically expressed and in human and mouse brain is in molar excess over the ATP synthase. Herein, we have used genetic approaches to ablate or overexpress IF1 in neurons to investigate its role in brain functions. IF1 inhibits a fraction of the ATP synthase under physiological conditions and regulates respiration, mtROS production and mitochondrial structure. Transcriptomic, proteomic and metabolomic analyses indicate that IF1 regulates synaptic transmission and cognition. Ablation of IF1 impairs short-term memory whereas IF1 overexpression increases basal synaptic transmission and learning by mtROS-dependent activation of the extracellular signal-regulated kinases 1/2 (ERK 1/2). Overall, we show that IF1 dose plays a fundamental role in the regulation of neuronal function by controlling the fraction of inhibited ATP synthase that acts as source of mitohormetic mtROS, further emphasizing the ATP synthase/IF1 as promising targets to treat cognitive disorders.
Project description:Sirturo or Bedaquiline has been shown to inhibit the ATP synthase of Mycobacterium tuberculosis. We used microarrays to investigate compound-induced gene expression changes in general as well as effects on the transcription of the different ATP synthase genes and other metabolic pathways.
Project description:To define TET3 function in cell differentiation, we profiled the intestinal epithelium at the single-cell level from wild-type and Tet3 knockout mice. Our works shows that, in the absence of TET3, enterocytes exhibit an aberrant differentiation trajectory and do not acquire a physiological cell identity due to an impairment in oxidative phosphorylation, specifically due to the reduced expression of genes encoding for ATP synthase membrane domain subunits. To assess whether the downregulation of ATP synthase subunits upon TET3 loss was due to a TET3 catalytic or non-catalytic activity, we examined global DNA methylation patterns in wild-type and Tet3 knockout intestinal epithelium by whole-genome bisulfite sequencing (WGBS). Our results show that these critical ATP synthase subunits coding-genes did not show any hyperDMR in their regulatory regions, excluding TET3 catalytic activity as the mechanism underlying their decreased gene expression and, pointing thus to TET3 non-catalytic activity.
Project description:Defects of mitochondrial functions lead in humans to vast array of usually multisystemic pathologies and several hundreds of diseases resulting from various defects of mitochondria biogenesis and maintenance, defects of respiratory chain complexes (OXPHOS) or defects of individual mitochondrial proteins are known. We used Agilent Whole Human Genome Microarray for gene expression profiling of genetically heterogeneous group of 13 patients with biochemically proven ATP synthase deficiency. Gene expression data analysis allowed classification of patients into several distinct groups, provided information on subgroup and patient specific gene expression profiles, defined candidate disease causing genes and gave basic information on pathogenic mechanisms associated with ATP synthase deficiency. Keywords: ATP synthase, mitochondrial biogenesis, ROS, gene expression, microarray, human Two-condition experiment, patients vs. controls cells. Biological replicates: 9 control, 13 patients, independently grown and harvested.