scholarly journals Aging of Podospora anserina Leads to Alterations of OXPHOS and the Induction of Non-Mitochondrial Salvage Pathways

Cells ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3319
Author(s):  
Verena Warnsmann ◽  
Jana Meisterknecht ◽  
Ilka Wittig ◽  
Heinz D. Osiewacz
Keyword(s):  
Protein Complexes ◽  
Mitochondrial Protein ◽  
Podospora Anserina ◽  
Mitochondrial Morphology ◽  
Complex Iv ◽  
Protein Levels ◽  
Age Dependent ◽  
Functionally Impaired ◽  
Salvage Pathways

The accumulation of functionally impaired mitochondria is a key event in aging. Previous works with the fungal aging model Podospora anserina demonstrated pronounced age-dependent changes of mitochondrial morphology and ultrastructure, as well as alterations of transcript and protein levels, including individual proteins of the oxidative phosphorylation (OXPHOS). The identified protein changes do not reflect the level of the whole protein complexes as they function in-vivo. In the present study, we investigated in detail the age-dependent changes of assembled mitochondrial protein complexes, using complexome profiling. We observed pronounced age-depen-dent alterations of the OXPHOS complexes, including the loss of mitochondrial respiratory supercomplexes (mtRSCs) and a reduction in the abundance of complex I and complex IV. Additionally, we identified a switch from the standard complex IV-dependent respiration to an alternative respiration during the aging of the P. anserina wild type. Interestingly, we identified proteasome components, as well as endoplasmic reticulum (ER) proteins, for which the recruitment to mitochondria appeared to be increased in the mitochondria of older cultures. Overall, our data demonstrate pronounced age-dependent alterations of the protein complexes involved in energy transduction and suggest the induction of different non-mitochondrial salvage pathways, to counteract the age-dependent mitochondrial impairments which occur during aging.

scholarly journals Temporal Profiling of the Cortical Synaptic Mitochondrial Proteome Identifies Ageing Associated Regulators of Stability

Cells ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3403
Author(s):  
Laura C. Graham ◽  
Rachel A. Kline ◽  
Douglas J. Lamont ◽  
Thomas H. Gillingwater ◽  
Neil A. Mabbott ◽  
...  
Keyword(s):  
Protein Expression ◽  
Expression Profiles ◽  
Mitochondrial Protein ◽  
Wild Type Mouse ◽  
Proteomic Profiling ◽  
Temporal Regulation ◽  
Mitochondrial Proteome ◽  
Age Dependent ◽  
Protein Expression Profiles

Synapses are particularly susceptible to the effects of advancing age, and mitochondria have long been implicated as organelles contributing to this compartmental vulnerability. Despite this, the mitochondrial molecular cascades promoting age-dependent synaptic demise remain to be elucidated. Here, we sought to examine how the synaptic mitochondrial proteome (including strongly mitochondrial associated proteins) was dynamically and temporally regulated throughout ageing to determine whether alterations in the expression of individual candidates can influence synaptic stability/morphology. Proteomic profiling of wild-type mouse cortical synaptic and non-synaptic mitochondria across the lifespan revealed significant age-dependent heterogeneity between mitochondrial subpopulations, with aged organelles exhibiting unique protein expression profiles. Recapitulation of aged synaptic mitochondrial protein expression at the Drosophila neuromuscular junction has the propensity to perturb the synaptic architecture, demonstrating that temporal regulation of the mitochondrial proteome may directly modulate the stability of the synapse in vivo.

scholarly journals Genomic analyses of glycine decarboxylase neurogenic mutations, yield a large scale prediction model for prenatal disease

2020 ◽  
Author(s):  
Joseph D. Farris ◽  
Md. Suhail Alam ◽  
Arpitha MysoreRajashekara ◽  
Kasturi Haldar
Keyword(s):  
Neurological Disease ◽  
Large Scale ◽  
Mitochondrial Protein ◽  
Glycine Decarboxylase ◽  
Linear Scale ◽  
Disease Outcomes ◽  
Genomic Analyses ◽  
Age Dependent ◽  
Genome Level

AbstractGlycine decarboxylase (GLDC) is a mitochondrial protein, hundreds of mutations in which cause a neurometabolic disorder Non-ketotic Hyperglycinemia (NKH), associated with elevation of plasma glycine. But why a mutation induces severe or attenuated neurological disease is poorly understood. We combined a human multiparametric mutation scale that separates severe from attenuated clinical, neurological disease, with new in silico tools to assess 238 of 255 NKH mutations in murine GLDC. We unified novel murine and human genome level-analyses across a linear scale of neurological severity, with in vivo evidence from mice engineered with a top-ranking attenuated mutation and another mutation >10 times more pathogenic and integrated the data in a model of pre- and post-natal disease outcomes, relevant for over a hundred major and minor neurogenic mutations. Our findings suggest that highly severe neurogenic mutations predict fatal, prenatal disease that can be remedied by metabolic supplementation of dams, in absence of amelioration of persistent and age-dependent elevation of plasma glycine.

scholarly journals PDE2 Inhibits PKA-Mediated Phosphorylation of TFAM to Promote Mitochondrial Ca2+-Induced Colorectal Cancer Growth

2021 ◽  
Vol 11 ◽  
Author(s):  
Yilin Zhao ◽  
Yaya Wang ◽  
Jing Zhao ◽  
Zhaohui Zhang ◽  
Mingpeng Jin ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Critical Role ◽  
Mitochondrial Protein ◽  
Fold Increase ◽  
Protein Levels ◽  
Mitochondrial Transcription Factor ◽  
Mitochondrial Transcription Factor A ◽  
Regulatory Effects

Growing evidence indicates that the dysregulation of mitochondrial calcium (Ca2+) plays a critical role in the growth of tumor cells, including colorectal cancer (CRC). However, the underling mechanism is not fully elucidated. In this study, the regulatory effects of mitochondrial Ca2+ on phosphodiesterase 2 (PDE2)/cAMP/PKA axis and the phosphorylation of mitochondrial transcription factor A (TFAM) as well as the growth of CRC cells were systematically investigated both in vitro and in vivo. Our findings demonstrated that MCU-induced mitochondrial Ca2+ uptake activated mitochondrial PDE2 in CRC cells. Moreover, overexpression MCU in CRC led to a 1.9-fold increase in Ca2+ uptake compared to control cells. However, knockdown of MCU resulted in 1.5-fould decrease in Ca2+ uptake in mitochondria compared to the controls. Activation of mitochondrial PDE2 significantly inhibited the activity of mitochondrial protein kinase A (PKA), which subsequently leads to decreased phosphorylation of TFAM. Our data further revealed that PKA regulates the phosphorylation of TFAM and promotes the degradation of phosphorylated TFAM. Thus, TFAM protein levels accumulated in mitochondria when the activity of PKA was inhibited. Overall, this study showed that the overexpression of MCU enhanced CRC growth through promoting the accumulation of TFAM proteins in mitochondria. Conversely, knockdown of MCU in CRC cells resulted in decreased CRC growth. Collectively, these data suggest that the mitochondrial Ca2+-activated PDE2/cAMP/PKA axis plays a key role in regulating TFAM stability and the growth of CRC cells.

scholarly journals Luteolin Prevents Cardiac Dysfunction and Improves the Chemotherapeutic Efficacy of Doxorubicin in Breast Cancer

2021 ◽  
Vol 8 ◽  
Author(s):  
Youyang Shi ◽  
Feifei Li ◽  
Man Shen ◽  
Chenpin Sun ◽  
Wei Hao ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Mitochondrial Fission ◽  
Mitochondrial Morphology ◽  
Protective Effects ◽  
Myocardial Cells ◽  
Related Protein ◽  
Zebrafish Model ◽  
Protein Levels

Background: Doxorubicin (Dox) is one of the most effective chemotherapy agents used in the treatment of solid tumors and hematological malignancies. However, it causes dose-related cardiotoxicity that may lead to heart failure in patients. Luteolin (Lut) is a common flavonoid that exists in many types of plants. It has been studied for treating various diseases such as hypertension, inflammatory disorders, and cancer. In this study, we evaluated the cardioprotective and anticancer effects of Lut on Dox-induced cardiomyopathy in vitro and in vivo to explore related mechanisms in alleviating dynamin-related protein (Drp1)-mediated mitochondrial apoptosis.Methods: MTT and LDH assay were used to determine the viability and toxicity of cardiomyocytes treated with Dox and Lut. Flow cytometry was used to examine ROS levels, and electron and confocal microscopy was employed to assess the mitochondrial morphology. The level of apoptosis was examined by Hoechst 33258 staining. The protein levels of myocardial fission protein and apoptosis-related protein were examined using Western blot. Transcriptome analysis of the protective effect of Lut against Dox-induced cardiac toxicity in myocardial cells was performed using RNA sequencing technology. The protective effects of Lut against cardiotoxicity mediated by Dox in zebrafish were quantified. The effect of Lut increase the antitumor activity of Dox in breast cancer both in vitro and in vivo were further employed.Results: Lut ameliorated Dox-induced toxicity in H9c2 and AC16 cells. The level of oxidative stress was downregulated by Lut after Dox treatment of myocardial cells. Lut effectively reduced the increased mitochondrial fission post Dox stimulation in cardiomyocytes. Apoptosis, fission protein Drp1, and Ser616 phosphorylation were also increased post Dox and reduced by Lut. In the zebrafish model, Lut significantly preserved the ventricular function of zebrafish after Dox treatment. Moreover, in the mouse model, Lut prevented Dox-induced cardiotoxicity and enhanced the cytotoxicity in triple-negative breast cancer by inhibiting proliferation and metastasis and inducing apoptosis.

scholarly journals Effect of p53 on mitochondrial morphology, import, and assembly in skeletal muscle

2015 ◽  
Vol 308 (4) ◽  
pp. C319-C329 ◽  
Author(s):  
Ayesha Saleem ◽  
Sobia Iqbal ◽  
Yuan Zhang ◽  
David A. Hood
Keyword(s):  
Skeletal Muscle ◽  
Mitochondrial Function ◽  
Protein Import ◽  
Mitochondrial Dynamics ◽  
Mitochondrial Protein ◽  
Mitochondrial Morphology ◽  
Functional Impairments ◽  
Native Page ◽  
Complex Iv ◽  
Related Proteins

The purpose of this study was to investigate whether p53 regulates mitochondrial function via changes in mitochondrial protein import, complex IV (COX) assembly, or the expression of key proteins involved in mitochondrial dynamics and degradation. Mitochondria from p53 KO mice displayed ultra-structural alterations and were more punctate in appearance. This was accompanied by protein-specific alterations in fission, fusion, and mitophagy-related proteins. However, matrix-destined protein import into subsarcolemmal or intermyofibrillar mitochondria was unaffected in the absence of p53, despite mitochondrial subfraction-specific reductions in Tom20, Tim23, mtHsp70, and mtHsp60 in the knockout (KO) mitochondria. Complex IV activity in isolated mitochondria was also unchanged in KO mice, but two-dimensional blue native-PAGE revealed a reduction in the assembly of complex IV within the IMF fractions from KO mice in tandem with lower levels of the assembly protein Surf1. This observed defect in complex IV assembly may facilitate the previously documented impairment in mitochondrial function in p53 KO mice. We suspect that these morphological and functional impairments in mitochondria drive a decreased reliance on mitochondrial respiration as a means of energy production in skeletal muscle in the absence of p53.

Abstract TP282: Increased Resiliency of Astrocytic Mitochondria After Focal Ischemic Stroke in Juvenile Mice

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Evelyn K Shih ◽  
Sabrina DaSilva ◽  
Elizabeth Krizman ◽  
Meredith L Lee ◽  
Michael B Robinson
Keyword(s):  
Ischemic Stroke ◽  
Brain Injury ◽  
Viral Vectors ◽  
Fluorescent Protein ◽  
Stroke Onset ◽  
Mitochondrial Morphology ◽  
Post Stroke ◽  
Mca Occlusion ◽  
Age Dependent

Introduction: Astrocytes provide bioenergetic support to neurons, mediate neurovascular coupling, buffer extracellular ions, and limit excitotoxicity. They undergo many rapid changes following ischemic brain injury, which may shape the extent of damage. The role of astrocytic mitochondria in astroglial functioning and response to brain injury remain underexplored. We investigated age dependent changes to astrocytic mitochondria following focal ischemic stroke in vivo using a clot-based mouse model of middle cerebral artery (MCA) occlusion. Methods: Male and female wildtype C57BL/6N neonatal mice underwent retro-orbital injections of AAV2/5 viral vectors containing mitochondrial targeted enhanced green fluorescent protein under the control of the astrocyte-specific glial fibrillary acidic protein promoter. Mice were allowed to age to 21-35 days (juvenile group) or 10-20 weeks (adult group). Proximal right MCA occlusion was provoked via photothrombosis using Rose Bengal dye and a targeted 532 nm laser beam. Control mice underwent sham procedures. Mice were perfused at 1, 3 or 24 hours post-stroke onset. Brains were processed and sectioned for mitochondrial analysis ( n = 3 animals/30 cells per time point per age group). Quantitative analyses were performed using a novel mitochondrial morphology scoring system. Results: Penumbral astrocytic mitochondria are markedly reduced in density, demonstrate decreased network complexity and adopt punctate spherical morphology compared to contralateral non-stroke hemisphere and sham animals. These changes are present within 1 hour of stroke onset. Preliminary data indicate at least 50% change in adult mice. These changes are attenuated in juvenile mice, with increased recovery seen at 24 hours post-stroke ictus. Conclusions: Astrocytic mitochondria within the penumbra undergo rapid loss and morphologic changes suggestive of dysfunction following proximal MCA occlusion. These changes are less severe in young mice indicating age-dependent resiliency of astrocytic mitochondria to ischemic injury. Further investigation into the mechanisms underlying astrocytic mitochondrial resiliency in the developing brain may reveal new strategies to limit stroke injury and improve outcomes.

scholarly journals Cardiolipin is required for membrane docking of mitochondrial ribosomes and protein synthesis

2020 ◽  
Vol 133 (14) ◽  
pp. jcs240374 ◽  
Author(s):  
Richard G. Lee ◽  
Junjie Gao ◽  
Stefan J. Siira ◽  
Anne-Marie Shearwood ◽  
Judith A. Ermer ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Stress Responses ◽  
Protein Complexes ◽  
Mitochondrial Protein ◽  
Mitochondrial Morphology ◽  
Mitochondrial Translation ◽  
Inner Membrane ◽  
Mitochondrial Ribosomes ◽  
Mitochondrial Inner Membrane ◽  
Mitochondrial Ribosome

ABSTRACTThe mitochondrial inner membrane contains a unique phospholipid known as cardiolipin (CL), which stabilises the protein complexes embedded in the membrane and supports its overall structure. Recent evidence indicates that the mitochondrial ribosome may associate with the inner membrane to facilitate co-translational insertion of the hydrophobic oxidative phosphorylation (OXPHOS) proteins into the inner membrane. We generated three mutant knockout cell lines for the CL biosynthesis gene Crls1 to investigate the effects of CL loss on mitochondrial protein synthesis. Reduced CL levels caused altered mitochondrial morphology and transcriptome-wide changes that were accompanied by uncoordinated mitochondrial translation rates and impaired respiratory chain supercomplex formation. Aberrant protein synthesis was caused by impaired formation and distribution of mitochondrial ribosomes. Reduction or loss of CL resulted in divergent mitochondrial and endoplasmic reticulum stress responses. We show that CL is required to stabilise the interaction of the mitochondrial ribosome with the membrane via its association with OXA1 (also known as OXA1L) during active translation. This interaction facilitates insertion of newly synthesised mitochondrial proteins into the inner membrane and stabilises the respiratory supercomplexes.

scholarly journals The E1B 19K/Bcl-2–binding Protein Nip3 is a Dimeric Mitochondrial Protein that Activates Apoptosis

1997 ◽  
Vol 186 (12) ◽  
pp. 1975-1983 ◽  
Author(s):  
Gao Chen ◽  
Reena Ray ◽  
Don Dubik ◽  
Lianfa Shi ◽  
Jeannick Cizeau ◽  
...  
Keyword(s):  
Cell Death ◽  
Topoisomerase I ◽  
Transmembrane Domain ◽  
Binding Protein ◽  
Mitochondrial Protein ◽  
Interacting Protein ◽  
Protein Levels ◽  
Yeast Two Hybrid System

Nip3 (nineteen kD interacting protein-3) is an E1B 19K and Bcl-2 binding protein of unknown function. Nip3 is detected as both a 60- and 30-kD protein in vivo and in vitro and exhibits strong homologous interaction in a yeast two-hybrid system indicating that it can homodimerize. Nip3 is expressed in mitochondria and a mutant (Nip3163) lacking the putative transmembrane domain and COOH terminus does not dimerize or localize to mitochondria. Transient transfection of epitope-tagged Nip3 in Rat-1 fibroblasts and MCF-7 breast carcinoma induces apoptosis within 12 h while cells transfected with the Nip3163 mutant have a normal phenotype, suggesting that mitochondrial localization is necessary for induction of cell death. Nip3 overexpression increases the sensitivity to apoptosis induced by granzyme B and topoisomerase I and II inhibitors. After transfection, both Nip3 and Nip3163 protein levels decrease steadily over 48 h indicating that the protein is rapidly degraded and this occurs in the absence of cell death. Bcl-2 overexpression initially delays the onset of apoptosis induced by Nip3 but the resistance is completely overcome in longer periods of incubation. Nip3 protein levels are much higher and persist longer in Bcl-2 expressing cells. In conclusion, Nip3 is an apoptosis-inducing dimeric mitochondrial protein that can overcome Bcl-2 suppression.

scholarly journals Increased supraorganization of respiratory complexes is a dynamic multistep remodelling in response to proteostasis stress

2020 ◽  
Vol 133 (18) ◽  
pp. jcs248492
Author(s):  
Shivali Rawat ◽  
Suparna Ghosh ◽  
Debodyuti Mondal ◽  
Valpadashi Anusha ◽  
Swasti Raychaudhuri
Keyword(s):  
Complex I ◽  
Protein Complexes ◽  
Mitochondrial Protein ◽  
Complex Iii ◽  
Complex Iv ◽  
Mitochondrial Proteome ◽  
Respiratory Complexes ◽  
The Core ◽  
Mitochondrial Functions ◽  
Folding Pathways

ABSTRACTProteasome-mediated degradation of misfolded proteins prevents aggregation inside and outside mitochondria. But how do cells safeguard the mitochondrial proteome and mitochondrial functions despite increased aggregation during proteasome inactivation? Here, using a novel two-dimensional complexome profiling strategy, we report increased supraorganization of respiratory complexes (RCs) in proteasome-inhibited cells that occurs simultaneously with increased pelletable aggregation of RC subunits inside mitochondria. Complex II (CII) and complex V (CV) subunits are increasingly incorporated into oligomers. Complex I (CI), complex III (CIII) and complex IV (CIV) subunits are engaged in supercomplex formation. We unravel unique quinary states of supercomplexes during early proteostatic stress that exhibit plasticity and inequivalence of constituent RCs. The core stoichiometry of CI and CIII is preserved, whereas the composition of CIV varies. These partially disintegrated supercomplexes remain functionally competent via conformational optimization. Subsequently, increased stepwise integration of RC subunits into holocomplexes and supercomplexes re-establishes steady-state stoichiometry. Overall, the mechanism of increased supraorganization of RCs mimics the cooperative unfolding and folding pathways for protein folding, but is restricted to RCs and is not observed for any other mitochondrial protein complexes.This article has an associated First Person interview with the first author of the paper.

scholarly journals Post-Transcriptional Control of Coenzyme Q Biosynthesis Revealed by Transomic Analysis of the RNA-Binding Protein Puf3p

2017 ◽  
Author(s):  
Christopher P. Lapointe ◽  
Jonathan A. Stefely ◽  
Adam Jochem ◽  
Paul D. Hutchins ◽  
Gary M. Wilson ◽  
...  
Keyword(s):  
Transcriptional Control ◽  
Protein Import ◽  
Rna Binding ◽  
Protein Complexes ◽  
Binding Protein ◽  
Coenzyme Q ◽  
Mitochondrial Protein ◽  
Rna Binding Protein ◽  
List Type

SUMMARYCoenzyme Q (CoQ) is a redox active lipid required for mitochondrial oxidative phosphorylation (OxPhos). How CoQ biosynthesis is coordinated with the biogenesis of OxPhos protein complexes is unclear. Here, we show that the Saccharomyces cerevisiae RNA-binding protein (RBP) Puf3p directly regulates CoQ biosynthesis. To establish the mechanism for this regulation, we employed a transomic strategy to identify mRNAs that not only bind Puf3p, but also are regulated by Puf3p in vivo. The CoQ biosynthesis enzyme Coq5p is a critical Put3p target: Puf3p regulates the level of Coq5p and prevents its toxicity, thereby enabling efficient CoQ production. In parallel, Puf3p represses a specific set of proteins involved in mitochondrial protein import, translation, and OxPhos complex assembly — pathways essential to prime mitochondrial biogenesis. Our data reveal a mechanism for post-transcriptionally coordinating CoQ production with OxPhos biogenesis and, more broadly, demonstrate the power of transomics for defining genuine targets of RBPs.HIGHLIGHTSThe RNA binding protein (RBP) Puf3p regulates coenzyme Q (CoQ) biosynthesisTransomic analysis of RNAs, proteins, lipids, and metabolites defines RBP targetsPuf3p regulates the potentially toxic CoQ biosynthesis enzyme Coq5pPuf3p couples regulation of CoQ with a broader program for controlling mitochondria

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