The ectoparasitic mite Varroa destructor transmits and triggers viral infections that have deleterious effects on honey bee colonies worldwide. We performed a manipulative experiment in which worker bees collected at emergence were exposed to Varroa for 72 h, and their proteomes were compared with those of untreated control bees. Label-free quantitative proteomics identified 77 differentially expressed A. mellifera proteins (DEPs). In addition, viral proteins were identified by orthogonal analysis, and most importantly, Deformed wing virus (DWV) was found at high levels/intensity in Varroa-exposed bees. Pathway enrichment analysis suggested that the main pathways affected included peroxisomal metabolism, cyto-/exoskeleton reorganization, and cuticular proteins. Detailed examination of individual DEPs revealed that additional changes in DEPs were associated with peroxisomal function. In addition, the proteome data support the importance of TGF-β signaling in Varroa-DWV interaction and the involvement of the mTORC1 and Hippo pathways. These results suggest that the effect of DWV on bees associated with Varroa feeding results in aberrant autophagy. In particular, autophagy is selectively modulated by peroxisomes, to which the observed proteome changes strongly corresponded. This study complements previous research with different study designs and suggests the importance of the peroxisome, which plays a key role in viral infections.
- Klíčová slova
- Apis mellifera, DWV, autophagy, host‐pathogen interaction, lipid metabolism,
- MeSH
- hmyzí proteiny metabolismus MeSH
- interakce hostitele a parazita MeSH
- peroxizomy * metabolismus virologie MeSH
- proteom metabolismus analýza MeSH
- proteomika metody MeSH
- RNA-viry * fyziologie MeSH
- signální transdukce MeSH
- Varroidae * virologie MeSH
- včely virologie parazitologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- hmyzí proteiny MeSH
- proteom MeSH
PURPOSE: Zellweger spectrum disorders (ZSDs) are known as autosomal recessive disorders caused by defective peroxisome biogenesis due to bi-allelic pathogenic variants in any of at least 13 different PEX genes. Here, we report 2 unrelated patients who present with an autosomal dominant ZSD. METHODS: We performed biochemical and genetic studies in blood and skin fibroblasts of the patients and demonstrated the pathogenicity of the identified PEX14 variants by functional cell studies. RESULTS: We identified 2 different single heterozygous de novo variants in the PEX14 genes of 2 patients diagnosed with ZSD. Both variants cause messenger RNA mis-splicing, leading to stable expression of similar C-terminally truncated PEX14 proteins. Functional studies indicated that the truncated PEX14 proteins lost their function in peroxisomal matrix protein import and cause increased degradation of peroxisomes, ie, pexophagy, thus exerting a dominant-negative effect on peroxisome functioning. Inhibition of pexophagy by different autophagy inhibitors or genetic knockdown of the peroxisomal autophagy receptor NBR1 resulted in restoration of peroxisomal functions in the patients' fibroblasts. CONCLUSION: Our finding of an autosomal dominant ZSD expands the genetic repertoire of ZSDs. Our study underscores that single heterozygous variants should not be ignored as possible genetic cause of diseases with an established autosomal recessive mode of inheritance.
- Klíčová slova
- Autophagy, Metabolic disorder, Peroxisomal disorder, Peroxisome, Peroxisome biogenesis,
- MeSH
- alely MeSH
- lidé MeSH
- peroxizomy genetika metabolismus MeSH
- proteiny genetika MeSH
- transport proteinů fyziologie MeSH
- Zellwegerův syndrom * genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- PEX14 protein, human MeSH Prohlížeč
- proteiny MeSH
Actin-related protein (ARP2/3) complex is a heteroheptameric protein complex, evolutionary conserved in all eukaryotic organisms. Its conserved role is based on the induction of actin polymerization at the interface between membranes and the cytoplasm. Plant ARP2/3 has been reported to participate in actin reorganization at the plasma membrane during polarized growth of trichomes and at the plasma membrane-endoplasmic reticulum contact sites. Here we demonstrate that individual plant subunits of ARP2/3 fused to fluorescent proteins form motile spot-like structures in the cytoplasm that are associated with peroxisomes in Arabidopsis and tobacco. ARP2/3 is found at the peroxisome periphery and contains the assembled ARP2/3 complex and the WAVE/SCAR complex subunit NAP1. This ARP2/3-positive peroxisomal domain colocalizes with the autophagosome and, under conditions that affect the autophagy, colocalization between ARP2/3 and the autophagosome increases. ARP2/3 subunits co-immunoprecipitate with ATG8f and peroxisome-associated ARP2/3 interact in vivo with the ATG8f marker. Since mutants lacking functional ARP2/3 complex have more peroxisomes than wild type, we suggest that ARP2/3 has a novel role in the process of peroxisome degradation by autophagy, called pexophagy.
- MeSH
- aktiny MeSH
- Arabidopsis * metabolismus MeSH
- komplex proteinů 2-3 souvisejících s aktinem metabolismus MeSH
- makroautofagie MeSH
- peroxizomy metabolismus MeSH
- proteiny huseníčku * metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- aktiny MeSH
- komplex proteinů 2-3 souvisejících s aktinem MeSH
- proteiny huseníčku * MeSH
BACKGROUND: Mitochondria and peroxisomes are the two organelles that are most affected during adaptation to microoxic or anoxic environments. Mitochondria are known to transform into anaerobic mitochondria, hydrogenosomes, mitosomes, and various transition stages in between, collectively called mitochondrion-related organelles (MROs), which vary in enzymatic capacity. Anaerobic peroxisomes were identified only recently, and their putatively most conserved function seems to be the metabolism of inositol. The group Archamoebae includes anaerobes bearing both anaerobic peroxisomes and MROs, specifically hydrogenosomes in free-living Mastigamoeba balamuthi and mitosomes in the human pathogen Entamoeba histolytica, while the organelles within the third lineage represented by Pelomyxa remain uncharacterized. RESULTS: We generated high-quality genome and transcriptome drafts from Pelomyxa schiedti using single-cell omics. These data provided clear evidence for anaerobic derivates of mitochondria and peroxisomes in this species, and corresponding vesicles were tentatively identified in electron micrographs. In silico reconstructed MRO metabolism harbors respiratory complex II, electron-transferring flavoprotein, a partial TCA cycle running presumably in the reductive direction, pyruvate:ferredoxin oxidoreductase, [FeFe]-hydrogenases, a glycine cleavage system, a sulfate activation pathway, and an expanded set of NIF enzymes for iron-sulfur cluster assembly. When expressed in the heterologous system of yeast, some of these candidates localized into mitochondria, supporting their involvement in the MRO metabolism. The putative functions of P. schiedti peroxisomes could be pyridoxal 5'-phosphate biosynthesis, amino acid and carbohydrate metabolism, and hydrolase activities. Unexpectedly, out of 67 predicted peroxisomal enzymes, only four were also reported in M. balamuthi, namely peroxisomal processing peptidase, nudix hydrolase, inositol 2-dehydrogenase, and D-lactate dehydrogenase. Localizations in yeast corroborated peroxisomal functions of the latter two. CONCLUSIONS: This study revealed the presence and partially annotated the function of anaerobic derivates of mitochondria and peroxisomes in P. schiedti using single-cell genomics, localizations in yeast heterologous systems, and transmission electron microscopy. The MRO metabolism resembles that of M. balamuthi and most likely reflects the state in the common ancestor of Archamoebae. The peroxisomal metabolism is strikingly richer in P. schiedti. The presence of myo-inositol 2-dehydrogenase in the predicted peroxisomal proteome corroborates the situation in other Archamoebae, but future experimental evidence is needed to verify additional functions of this organelle.
- Klíčová slova
- Anaerobic peroxisome, Anaerobiosis, FeS cluster assembly, Hydrogenosome, Mitochondrion-related organelle, Pelomyxa, Single-cell genomics,
- MeSH
- Amoeba * genetika metabolismus MeSH
- anaerobióza MeSH
- Archamoebae * genetika metabolismus MeSH
- genomika MeSH
- lidé MeSH
- mitochondrie metabolismus MeSH
- peroxizomy metabolismus MeSH
- Saccharomyces cerevisiae MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Entamoeba histolytica is believed to be devoid of peroxisomes, like most anaerobic protists. In this work, we provided the first evidence that peroxisomes are present in E. histolytica, although only seven proteins responsible for peroxisome biogenesis (peroxins) were identified (Pex1, Pex6, Pex5, Pex11, Pex14, Pex16, and Pex19). Targeting matrix proteins to peroxisomes is reduced to the PTS1-dependent pathway mediated via the soluble Pex5 receptor, while the PTS2 receptor Pex7 is absent. Immunofluorescence microscopy showed that peroxisomal markers (Pex5, Pex14, Pex16, Pex19) are present in vesicles distinct from mitosomes, the endoplasmic reticulum, and the endosome/phagosome system, except Pex11, which has dual localization in peroxisomes and mitosomes. Immunoelectron microscopy revealed that Pex14 localized to vesicles of approximately 90-100 nm in diameter. Proteomic analyses of affinity-purified peroxisomes and in silico PTS1 predictions provided datasets of 655 and 56 peroxisomal candidates, respectively; however, only six proteins were shared by both datasets, including myo-inositol dehydrogenase (myo-IDH). Peroxisomal NAD-dependent myo-IDH appeared to be a dimeric enzyme with high affinity to myo-inositol (Km 0.044 mM) and can utilize also scyllo-inositol, D-glucose and D-xylose as substrates. Phylogenetic analyses revealed that orthologs of myo-IDH with PTS1 are present in E. dispar, E. nutalli and E. moshkovskii but not in E. invadens, and form a monophyletic clade of mostly peroxisomal orthologs with free-living Mastigamoeba balamuthi and Pelomyxa schiedti. The presence of peroxisomes in E. histolytica and other archamoebae breaks the paradigm of peroxisome absence in anaerobes and provides a new potential target for the development of antiparasitic drugs.
- MeSH
- anaerobióza MeSH
- Entamoeba histolytica metabolismus MeSH
- fylogeneze MeSH
- inositol metabolismus MeSH
- mutace * MeSH
- peroxiny metabolismus MeSH
- peroxizomální cílové signály * MeSH
- peroxizomy metabolismus MeSH
- protozoální proteiny genetika metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- inositol MeSH
- peroxiny MeSH
- peroxizomální cílové signály * MeSH
- protozoální proteiny MeSH
The type 2 secretion system (T2SS) is present in some Gram-negative eubacteria and used to secrete proteins across the outer membrane. Here we report that certain representative heteroloboseans, jakobids, malawimonads and hemimastigotes unexpectedly possess homologues of core T2SS components. We show that at least some of them are present in mitochondria, and their behaviour in biochemical assays is consistent with the presence of a mitochondrial T2SS-derived system (miT2SS). We additionally identified 23 protein families co-occurring with miT2SS in eukaryotes. Seven of these proteins could be directly linked to the core miT2SS by functional data and/or sequence features, whereas others may represent different parts of a broader functional pathway, possibly also involving the peroxisome. Its distribution in eukaryotes and phylogenetic evidence together indicate that the miT2SS-centred pathway is an ancestral eukaryotic trait. Our findings thus have direct implications for the functional properties of the early mitochondrion.
- MeSH
- biologické modely MeSH
- Eukaryota klasifikace genetika metabolismus MeSH
- fylogeneze MeSH
- gramnegativní bakterie klasifikace genetika metabolismus MeSH
- konzervovaná sekvence MeSH
- mitochondriální proteiny klasifikace genetika metabolismus MeSH
- mitochondrie genetika metabolismus MeSH
- molekulární evoluce * MeSH
- molekulární modely MeSH
- Naegleria klasifikace genetika metabolismus MeSH
- peroxizomy metabolismus MeSH
- protozoální proteiny klasifikace genetika metabolismus MeSH
- sekreční systém typu II klasifikace genetika metabolismus MeSH
- sekvence aminokyselin MeSH
- sekvenční homologie aminokyselin MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- mitochondriální proteiny MeSH
- protozoální proteiny MeSH
- sekreční systém typu II MeSH
Baker's yeast is a valuable model system for the study of biological aging as it can be utilized for the measurement of replicative and chronological life spans in response to interventions. Whereas replicative aging in Saccharomyces cerevisiae mirrors dividing mammalian cells, chronological aging is seen in non-dividing cells. Aging is strongly influenced by the cellular organelles, especially by mitochondria which house essential functions like oxidative phosphorylation. Additionally, peroxisomes were shown to modulate the aging process, mainly by their turnover of reactive oxygen species. There is a fundamental interest in understanding how mitochondria and peroxisomes contribute to cellular aging. This work analyzes chronological aging in yeast mutants that are affected in peroxisomal proliferation and inheritance. Deletion of INP1 (retention of peroxisomes in the mother cell) or PEX11 (division of peroxisomes) leads to clearly reduced life spans compared to the wild-type control under conditions which depend on peroxisomal metabolism. Δinp1 cells are long-lived in contrast to the wild type and Δpex11 when assayed under conditions that not necessitate peroxisome function. Neither treatment affects the index of respiratory capacity, indicating fully functional mitochondria. Evaluation of stress resistances reveals that Δinp1 has significantly higher resistance to the apoptosis elicitor acetic acid. Old Δpex11 cells from an oleate culture are more susceptible to hydrogen peroxide treatment compared to Δinp1 and the wild type. Finally, aged cells are hyper-sensitive to heat shock treatment in contrast to young cells.
- MeSH
- delece genu MeSH
- membránové proteiny genetika metabolismus MeSH
- mikrobiální viabilita MeSH
- peroxiny genetika metabolismus MeSH
- peroxizomy genetika metabolismus MeSH
- proliferace buněk MeSH
- reaktivní formy kyslíku metabolismus MeSH
- Saccharomyces cerevisiae - proteiny genetika metabolismus MeSH
- Saccharomyces cerevisiae genetika růst a vývoj metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- INP1 protein, S cerevisiae MeSH Prohlížeč
- membránové proteiny MeSH
- peroxiny MeSH
- PEX11 protein, S cerevisiae MeSH Prohlížeč
- reaktivní formy kyslíku MeSH
- Saccharomyces cerevisiae - proteiny MeSH
The adaptation of eukaryotic cells to anaerobic conditions is reflected by substantial changes to mitochondrial metabolism and functional reduction. Hydrogenosomes belong among the most modified mitochondrial derivative and generate molecular hydrogen concomitant with ATP synthesis. The reduction of mitochondria is frequently associated with loss of peroxisomes, which compartmentalize pathways that generate reactive oxygen species (ROS) and thus protect against cellular damage. The biogenesis and function of peroxisomes are tightly coupled with mitochondria. These organelles share fission machinery components, oxidative metabolism pathways, ROS scavenging activities, and some metabolites. The loss of peroxisomes in eukaryotes with reduced mitochondria is thus not unexpected. Surprisingly, we identified peroxisomes in the anaerobic, hydrogenosome-bearing protist Mastigamoeba balamuthi We found a conserved set of peroxin (Pex) proteins that are required for protein import, peroxisomal growth, and division. Key membrane-associated Pexs (MbPex3, MbPex11, and MbPex14) were visualized in numerous vesicles distinct from hydrogenosomes, the endoplasmic reticulum (ER), and Golgi complex. Proteomic analysis of cellular fractions and prediction of peroxisomal targeting signals (PTS1/PTS2) identified 51 putative peroxisomal matrix proteins. Expression of selected proteins in Saccharomyces cerevisiae revealed specific targeting to peroxisomes. The matrix proteins identified included components of acyl-CoA and carbohydrate metabolism and pyrimidine and CoA biosynthesis, whereas no components related to either β-oxidation or catalase were present. In conclusion, we identified a subclass of peroxisomes, named "anaerobic" peroxisomes that shift the current paradigm and turn attention to the reductive evolution of peroxisomes in anaerobic organisms.
- Klíčová slova
- Mastigamoeba balamuthi, anaerobiosis, mitochodria, peroxisome,
- MeSH
- anaerobióza MeSH
- Archamoebae genetika metabolismus MeSH
- mitochondrie genetika metabolismus MeSH
- oxidace-redukce MeSH
- peroxiny genetika metabolismus MeSH
- peroxizomy genetika metabolismus MeSH
- protozoální proteiny genetika metabolismus MeSH
- reaktivní formy kyslíku metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- peroxiny MeSH
- protozoální proteiny MeSH
- reaktivní formy kyslíku MeSH
INTRODUCTION: Currently, no therapies are available for Zellweger spectrum disorders (ZSDs), a group of genetic metabolic disorders characterised by a deficiency of functional peroxisomes. In a previous study, we showed that oral cholic acid (CA) treatment can suppress bile acid synthesis in ZSD patients and, thereby, decrease plasma levels of toxic C27 -bile acid intermediates, one of the biochemical abnormalities in these patients. However, no effect on clinically relevant outcome measures could be observed after 9 months of CA treatment. It was noted that, in patients with advanced liver disease, caution is needed because of possible hepatotoxicity. METHODS: An extension study of the previously conducted pretest-posttest design study was conducted including 17 patients with a ZSD. All patients received oral CA for an additional period of 12 months, encompassing a total of 21 months of treatment. Multiple clinically relevant parameters and markers for bile acid synthesis were assessed after 15 and 21 months of treatment. RESULTS: Bile acid synthesis was still suppressed after 21 months of CA treatment, accompanied with reduced levels of C27 -bile acid intermediates in plasma. These levels significantly increased again after discontinuation of CA. No significant changes were found in liver tests, liver elasticity, coagulation parameters, fat-soluble vitamin levels or body weight. CONCLUSIONS: Although CA treatment did lead to reduced levels of toxic C27 -bile acid intermediates in ZSD patients without severe liver fibrosis or cirrhosis, no improvement of clinically relevant parameters was observed after 21 months of treatment. We discuss the implications for CA therapy in ZSD based on these results.
- MeSH
- aplikace orální MeSH
- biologické markery krev MeSH
- dítě MeSH
- dospělí MeSH
- játra metabolismus MeSH
- kyselina cholová krev terapeutické užití MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- nemoci jater farmakoterapie metabolismus MeSH
- peroxizomy metabolismus MeSH
- předškolní dítě MeSH
- Zellwegerův syndrom krev farmakoterapie metabolismus MeSH
- žlučové kyseliny a soli metabolismus MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- předškolní dítě MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- biologické markery MeSH
- kyselina cholová MeSH
- žlučové kyseliny a soli MeSH
: Jasmonic acid (JA) and its related derivatives are ubiquitously occurring compounds of land plants acting in numerous stress responses and development. Recent studies on evolution of JA and other oxylipins indicated conserved biosynthesis. JA formation is initiated by oxygenation of α-linolenic acid (α-LeA, 18:3) or 16:3 fatty acid of chloroplast membranes leading to 12-oxo-phytodienoic acid (OPDA) as intermediate compound, but in Marchantiapolymorpha and Physcomitrellapatens, OPDA and some of its derivatives are final products active in a conserved signaling pathway. JA formation and its metabolic conversion take place in chloroplasts, peroxisomes and cytosol, respectively. Metabolites of JA are formed in 12 different pathways leading to active, inactive and partially active compounds. The isoleucine conjugate of JA (JA-Ile) is the ligand of the receptor component COI1 in vascular plants, whereas in the bryophyte M. polymorpha COI1 perceives an OPDA derivative indicating its functionally conserved activity. JA-induced gene expressions in the numerous biotic and abiotic stress responses and development are initiated in a well-studied complex regulation by homeostasis of transcription factors functioning as repressors and activators.
- Klíčová slova
- JA biosynthetic enzymes, JA bypass, JA signaling, Jasmonic acid (JA) metabolites, active JA compounds, occurrence, transcription factors,
- MeSH
- chloroplasty metabolismus MeSH
- cyklopentany metabolismus MeSH
- druhová specificita MeSH
- kyselina alfa-linolenová metabolismus MeSH
- Marchantia metabolismus MeSH
- mastné kyseliny metabolismus MeSH
- mechy metabolismus MeSH
- metabolické sítě a dráhy MeSH
- nenasycené mastné kyseliny metabolismus MeSH
- oxylipiny metabolismus MeSH
- peroxizomy metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- Názvy látek
- 12-oxophytodienoic acid MeSH Prohlížeč
- cyklopentany MeSH
- jasmonic acid MeSH Prohlížeč
- kyselina alfa-linolenová MeSH
- mastné kyseliny MeSH
- nenasycené mastné kyseliny MeSH
- oxylipiny MeSH
