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1.
Methods Mol Biol ; 2623: 97-111, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36602682

RESUMO

Long-range transport of organelles and other cellular cargoes along microtubules is driven by kinesin and dynein motor proteins in complex with cargo-specific adaptors. While some adaptors interact exclusively with a single motor, other adaptors interact with both kinesin and dynein motors. However, the mechanisms by which bidirectional motor adaptors coordinate opposing microtubule motors are not fully understood. While single-molecule studies of adaptors using purified proteins can provide key insight into motor adaptor function, these studies may be limited by the absence of cellular factors that regulate or coordinate motor function. As a result, motility assays using cell lysates have been developed to gain insight into motor adaptor function in a more physiological context. These assays are a powerful means to dissect the regulation of motor adaptors as cell lysates contain endogenous microtubule motors and additional factors that regulate motor function. Further, this system is highly tractable as individual proteins can readily be added or removed via overexpression or knockdown in cells. Here, we describe a protocol for in vitro reconstitution of motor-driven transport along dynamic microtubules at single-molecule resolution using total internal reflection fluorescence microscopy of cell lysates.


Assuntos
Dineínas , Proteínas Associadas aos Microtúbulos , Dineínas/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Cinesinas/metabolismo , Microtúbulos/metabolismo , Organelas/metabolismo
2.
Trends Neurosci ; 46(2): 137-152, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36635110

RESUMO

Efforts to understand how mitochondrial dysfunction contributes to neurodegeneration have primarily focussed on the role of mitochondria in neuronal energy metabolism. However, progress in understanding the etiological nature of emerging mitochondrial functions has yielded new ideas about the mitochondrial basis of neurological disease. Studies aimed at deciphering how mitochondria signal through interorganellar contacts, vesicular trafficking, and metabolic transmission have revealed that mitochondrial regulation of immunometabolism, cell death, organelle dynamics, and neuroimmune interplay are critical determinants of neural health. Moreover, the homeostatic mechanisms that exist to protect mitochondrial health through turnover via nanoscale proteostasis and lysosomal degradation have become integrated within mitochondrial signalling pathways to support metabolic plasticity and stress responses in the nervous system. This review highlights how these distinct mitochondrial pathways converge to influence neurological health and contribute to disease pathology.


Assuntos
Mitocôndrias , Doenças do Sistema Nervoso , Humanos , Mitocôndrias/metabolismo , Organelas/metabolismo , Homeostase , Transdução de Sinais , Doenças do Sistema Nervoso/metabolismo
3.
Nat Commun ; 14(1): 421, 2023 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-36702825

RESUMO

Inspired by the role of intracellular liquid-liquid phase separation (LLPS) in formation of membraneless organelles, there is great interest in developing dynamic compartments formed by LLPS of intrinsically disordered proteins (IDPs) or short peptides. However, the molecular mechanisms underlying the formation of biomolecular condensates have not been fully elucidated, rendering on-demand design of synthetic condensates with tailored physico-chemical functionalities a significant challenge. To address this need, here we design a library of LLPS-promoting peptide building blocks composed of various assembly domains. We show that the LLPS propensity, dynamics, and encapsulation efficiency of compartments can be tuned by changes to the peptide composition. Specifically, with the aid of Raman and NMR spectroscopy, we show that interactions between arginine and aromatic amino acids underlie droplet formation, and that both intra- and intermolecular interactions dictate droplet dynamics. The resulting sequence-structure-function correlation could support the future development of compartments for a variety of applications.


Assuntos
Condensados Biomoleculares , Proteínas Intrinsicamente Desordenadas , Aminoácidos Aromáticos , Espectroscopia de Ressonância Magnética , Peptídeos/análise , Proteínas Intrinsicamente Desordenadas/metabolismo , Organelas/metabolismo
4.
Nat Commun ; 14(1): 480, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36717559

RESUMO

Diatoms are unicellular algae characterized by silica cell walls. These silica elements are known to be formed intracellularly in membrane-bound silica deposition vesicles and exocytosed after completion. How diatoms maintain membrane homeostasis during the exocytosis of these large and rigid silica elements remains unknown. Here we study the membrane dynamics during cell wall formation and exocytosis in two model diatom species, using live-cell confocal microscopy, transmission electron microscopy and cryo-electron tomography. Our results show that during its formation, the mineral phase is in tight association with the silica deposition vesicle membranes, which form a precise mold of the delicate geometrical patterns. We find that during exocytosis, the distal silica deposition vesicle membrane and the plasma membrane gradually detach from the mineral and disintegrate in the extracellular space, without any noticeable endocytic retrieval or extracellular repurposing. We demonstrate that within the cell, the proximal silica deposition vesicle membrane becomes the new barrier between the cell and its environment, and assumes the role of a new plasma membrane. These results provide direct structural observations of diatom silica exocytosis, and point to an extraordinary mechanism in which membrane homeostasis is maintained by discarding, rather than recycling, significant membrane patches.


Assuntos
Diatomáceas , Diatomáceas/metabolismo , Parede Celular/metabolismo , Organelas/metabolismo , Dióxido de Silício/química , Exocitose
5.
Oxid Med Cell Longev ; 2023: 3400147, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36644574

RESUMO

Apoptosis has been extensively studied, whereas ferroptosis is a newly discovered form of regulated cell death that involves iron-dependent accumulations of lipid hydroperoxides. While these two cell death mechanisms were initially believed to be mutually exclusive, recent studies have revealed cellular contexts requiring a balanced interaction between them. Numerous subcellular sites and signaling molecules within these sites are involved in both processes, either as modules or switches that allow cells to choose on how to proceed. The close relationships between apoptosis and ferroptosis, as well as the possibility of switching from one to the other, are described in this review. To understand the crosstalk between apoptosis and ferroptosis, various organelle-specific mechanisms must be analyzed and compared. The ability to switch apoptosis to ferroptosis by targeting cellular organelles has a great potential in cancer therapy.


Assuntos
Ferroptose , Ferro/metabolismo , Apoptose , Morte Celular , Organelas/metabolismo
6.
Open Biol ; 13(1): 220238, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36629021

RESUMO

The endobiotic flagellate Monocercomonoides exilis is the only known eukaryote to have lost mitochondria and all its associated proteins in its evolutionary past. This final stage of the mitochondrial evolutionary pathway may serve as a model to explain events at their very beginning such as the initiation of protein import. We have assessed the capability of proteins from this eukaryote to enter emerging mitochondria using a specifically designed in vitro assay. Hydrogenosomes (reduced mitochondria) of Trichomonas vaginalis were incubated with a soluble protein pool derived from a cytosolic fraction of M. exilis, and proteins entering hydrogenosomes were subsequently detected by mass spectrometry. The assay detected 19 specifically and reproducibly imported proteins, and in 14 cases the import was confirmed by the overexpression of their tagged version in T. vaginalis. In most cases, only a small portion of the signal reached the hydrogenosomes, suggesting specific but inefficient transport. Most of these proteins represent enzymes of carbon metabolism, and none exhibited clear signatures of proteins targeted to hydrogenosomes or mitochondria, which is consistent with their inefficient import. The observed phenomenon may resemble a primaeval type of protein import which might play a role in the establishment of the organelle and shaping of its proteome in the initial stages of endosymbiosis.


Assuntos
Eucariotos , Proteínas de Protozoários , Eucariotos/metabolismo , Proteínas de Protozoários/metabolismo , Organelas/química , Organelas/metabolismo , Mitocôndrias/metabolismo , Transporte Proteico
7.
PLoS Biol ; 21(1): e3001937, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36602948

RESUMO

Apicomplexa are obligate intracellular parasites. While most species are restricted to specific hosts and cell types, Toxoplasma gondii can invade every nucleated cell derived from warm-blooded animals. This broad host range suggests that this parasite can recognize multiple host cell ligands or structures, leading to the activation of a central protein complex, which should be conserved in all apicomplexans. During invasion, the unique secretory organelles (micronemes and rhoptries) are sequentially released and several micronemal proteins have been suggested to be required for host cell recognition and invasion. However, to date, only few micronemal proteins have been demonstrated to be essential for invasion, suggesting functional redundancy that might allow such a broad host range. Cysteine Repeat Modular Proteins (CRMPs) are a family of apicomplexan-specific proteins. In T. gondii, two CRMPs are present in the genome, CRMPA (TGGT1_261080) and CRMPB (TGGT1_292020). Here, we demonstrate that both proteins form a complex that contains the additional proteins MIC15 and the thrombospondin type 1 domain-containing protein (TSP1). Disruption of this complex results in a block of rhoptry secretion and parasites being unable to invade the host cell. In conclusion, this complex is a central invasion complex conserved in all apicomplexans.


Assuntos
Toxoplasma , Animais , Toxoplasma/genética , Toxoplasma/metabolismo , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo , Organelas/metabolismo
8.
J Photochem Photobiol B ; 238: 112624, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36521315

RESUMO

Defects in mitochondrial proteostasis contribute to many disorders, including cancer, neurodegeneration, and metabolic and genetic diseases. A strategy aimed at restoring the damaged mitochondrial proteostasis is the mitochondrion-targeting and carrier-free delivery of exogenous functional proteins that can replace the endogenous dysfunctional proteins. The modification of a protein with a photolabile protecting group (PPG, i.e., photocage group) can be activated in situ by response to illumination, leading to release of the protein from its photocage. Here, the Cys and peptide photocages with coumarin were first prepared and characterized for proof of concept. Then, we designed a pair of photocage groups PPG-RhB and PPG-TPP using coumarin and mitochondrion-targeting Rhodamine B (RhB) and triphenylphosphine (TPP), and another pair of organelle-nontarget photocage groups Br-PPG and NO2-PPG for comparison. The proteins modified with these two pairs of photocage groups undergo photolysis in solutions, and can penetrate cell membrane toward their destinations in the carrier-free fashions. The intracellular protein photocages are in situ activated by illumination at 405 nm, and the proteins are released from their photocages in mitochondria and cytoplasm, respectively. This strategy of light-responsive and carrier-free cellular delivery enables mitochondrial and cytoplasmic accumulation of exogenous proteins.


Assuntos
Mitocôndrias , Organelas , Mitocôndrias/metabolismo , Fotólise , Organelas/metabolismo , Peptídeos/metabolismo , Cumarínicos
9.
Int J Biochem Cell Biol ; 154: 106345, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36521722

RESUMO

Mitochondria, endoplasmic reticulum and lysosomes are involved in different pathways that can regulate pre-synaptic function. In particular, they could modulate ATP availability in response to rapid changes, could control synaptic protein levels and adjust Ca2+ signalling, which could all impact on neuronal activity. Organelles functions in these processes need to be considered alone when describing the impact of pre-synaptic organelles on neurotransmission. However, the interplay among organelles, which occurs either via signalling pathways or through physical membranous contacts, has to be considered. In this brief review, the physiological role of organelles localized at the pre-synapse in neuronal function is discussed.


Assuntos
Neurônios , Organelas , Organelas/metabolismo , Neurônios/metabolismo , Sinapses/metabolismo , Retículo Endoplasmático/metabolismo , Mitocôndrias/metabolismo , Transmissão Sináptica , Cálcio/metabolismo
10.
Trends Cell Biol ; 32(1): 1-3, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34544610

RESUMO

Membraneless organelles (MLOs) present as a condensed metastable phase of different proteins and RNAs organized via liquid-liquid phase separation. Recent evidence suggests the extensive incorporation of molecular chaperones into the dynamic assembly of MLOs, where different chaperones coordinate to spatiotemporally maintain the protein homeostasis and avoid abnormal protein aggregation.


Assuntos
Condensados Biomoleculares , Organelas , Humanos , Chaperonas Moleculares/metabolismo , Organelas/metabolismo , RNA/metabolismo
11.
BMC Plant Biol ; 22(1): 583, 2022 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-36513981

RESUMO

BACKGROUND: Multiple organellar RNA editing factor (MORF) genes play key roles in chloroplast developmental processes by mediating RNA editing of Cytosine-to-Uracil conversion. However, the function of MORF genes in peach (Prunus persica), a perennial horticultural crop species of Rosaceae, is still not well known, particularly the resistance to biotic and abiotic stresses that threaten peach yield seriously. RESULTS: In this study, to reveal the regulatory roles of RNA editing in plant immunity, we implemented genome-wide analysis of peach MORF (PpMORF) genes in response to biotic and abiotic stresses. The chromosomal and subcellular location analysis showed that the identified seven PpMORF genes distributed on three peach chromosomes were mainly localized in the mitochondria and chloroplast. All the PpMORF genes were classified into six groups and one pair of PpMORF genes was tandemly duplicated. Based on the meta-analysis of two types of public RNA-seq data under different treatments (biotic and abiotic stresses), we observed down-regulated expression of PpMORF genes and reduced chloroplast RNA editing, especially the different response of PpMORF2 and PpMORF9 to pathogens infection between resistant and susceptible peach varieties, indicating the roles of MORF genes in stress response by modulating the RNA editing extent in plant immunity. Three upstream transcription factors (MYB3R-1, ZAT10, HSFB3) were identified under both stresses, they may regulate resistance adaption by modulating the PpMORF gene expression. CONCLUSION: These results provided the foundation for further analyses of the functions of MORF genes, in particular the roles of RNA editing in plant immunity. In addition, our findings will be conducive to clarifying the resistance mechanisms in peaches and open up avenues for breeding new cultivars with high resistance.


Assuntos
Prunus persica , Prunus persica/genética , Prunus persica/metabolismo , Edição de RNA , Melhoramento Vegetal , Organelas/metabolismo , Imunidade Vegetal/genética , Regulação da Expressão Gênica de Plantas
12.
Int J Mol Sci ; 23(23)2022 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-36499680

RESUMO

Interorganelle membrane contact sites (MCS) are areas of close vicinity between the membranes of two organelles that are maintained by protein tethers. Recently, a significant research effort has been made to study MCS, as they are implicated in a wide range of biological functions, such as organelle biogenesis and division, apoptosis, autophagy, and ion and phospholipid homeostasis. Their composition, characteristics, and dynamics can be studied by different techniques, but in recent years super-resolution fluorescence microscopy (SRFM) has emerged as a powerful tool for studying MCS. In this review, we first explore the main characteristics and biological functions of MCS and summarize the different approaches for studying them. Then, we center on SRFM techniques that have been used to study MCS. For each of the approaches, we summarize their working principle, discuss their advantages and limitations, and explore the main discoveries they have uncovered in the field of MCS.


Assuntos
Membranas Mitocondriais , Organelas , Microscopia de Fluorescência/métodos , Organelas/metabolismo
13.
Cells ; 11(24)2022 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-36552873

RESUMO

Ubiquitination is a critical type of post-translational modification in eukaryotic cells. It is involved in regulating nearly all cellular processes in the cytosol and nucleus. Mitochondria, known as the metabolism heart of the cell, are organelles that evolved from bacteria. Using the subcellular compartment-dependent α-complementation, we detect multiple components of ubiquitination machinery as being eclipsed distributed to yeast mitochondria. Ubiquitin conjugates and mono-ubiquitin can be detected in lysates of isolated mitochondria from cells expressing HA-Ub and treated with trypsin. By expressing MTS (mitochondrial targeting sequence) targeted HA-tagged ubiquitin, we demonstrate that certain ubiquitination events specifically occur in yeast mitochondria and are independent of proteasome activity. Importantly, we show that the E2 Rad6 affects the pattern of protein ubiquitination in mitochondria and provides an in vivo assay for its activity in the matrix of the organelle. This study shows that ubiquitination occurs in the mitochondrial matrix by eclipsed targeted components of the ubiquitin machinery, providing a new perspective on mitochondrial and ubiquitination research.


Assuntos
Mitocôndrias , Saccharomyces cerevisiae , Saccharomyces cerevisiae/metabolismo , Ubiquitinação , Mitocôndrias/metabolismo , Ubiquitina/metabolismo , Organelas/metabolismo
14.
Viruses ; 14(12)2022 11 29.
Artigo em Inglês | MEDLINE | ID: mdl-36560676

RESUMO

Oxysterol-binding protein (OSBP) is a host factor required for enterovirus (EV) replication. OSBP locates at membrane contact site and acts as a lipid exchanger of cholesterol and phosphatidylinositol 4-phosphate (PI4P) between cellular organelles; however, the essential domains required for the viral replication remain unknown. In this study, we define essential domains of OSBP for poliovirus (PV) replication by a functional dominance assay with a series of deletion variants of OSBP. We show that the pleckstrin homology domain (PHD) and the ligand-binding domain, but not the N-terminal intrinsically disordered domain, coiled-coil region, or the FFAT motif, are essential for PV replication. The PHD serves as the primary determinant of OSBP targeting to the replication organelle in the infected cells. These results suggest that not all the domains that support important biological functions of OSBP are essential for the viral replication.


Assuntos
Enterovirus , Oxisteróis , Poliovirus , Receptores de Esteroides , Poliovirus/genética , Poliovirus/metabolismo , Enterovirus/metabolismo , Organelas/metabolismo , Receptores de Esteroides/genética , Replicação Viral
15.
Cell Death Dis ; 13(12): 1040, 2022 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-36517470

RESUMO

Ferroptosis is a recently-defined tumor suppression mechanism, but the sensitivity of many tumorigenic cells to ferroptosis is limited by their deficient expression of acyl-CoA synthetase long-chain family member 4 (ACSL4). Here, we report the discovery of a photosensitizer, namely TPCI, which can evoke ACSL4-independent ferroptosis of cancer cells in photodynamic therapy. Through co-localization with 12-lipoxygenase (ALOX12) in multiple subcellular organelles, TPCI activates ALOX12 to generate lipid reactive oxygen species in large quantity and trigger cell ferroptosis. Intriguingly, confining TPCI exclusively in lysosomes switches the cell death from ferroptosis to apoptosis. More strikingly, the ferroptosis mediated by TPCI-induced ALOX12 activation does not require the participation of ACSL4. Therefore, our study identifies TPCI as the first ALOX12 activator to induce ferroptosis independent of ACSL4, which renders a viable therapeutic approach on the basis of distinct ferroptosis of cancer cells, regardless their ACSL4 expressions.


Assuntos
Ferroptose , Fármacos Fotossensibilizantes/farmacologia , Coenzima A Ligases/metabolismo , Apoptose , Organelas/metabolismo
16.
Mol Biol Cell ; 33(14): ae4, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36399622

RESUMO

In 1956, referring to the emerging application of electron microscopy to the study of eukaryotic cells, Keith R. Porter wrote, "For those of us who are fortunate to be part of this new development, these are days of great interest and opportunity." Those early days left us a rich legacy of knowledge on the internal organization of eukaryotic cells that provides a framework for current research on cell structure and function. In this vein, my long-time quest has been to understand how proteins and organelles travel through the cytoplasm to reach their respective destinations within the cell. This research has led us to elucidate various mechanisms of protein sorting and organelle transport and how defects in these mechanisms cause human disease.


Assuntos
Organelas , Humanos , Organelas/metabolismo , Microscopia Eletrônica , Transporte Biológico/fisiologia , Citoplasma/metabolismo , Transporte Proteico
17.
FEBS J ; 289(22): 6822-6831, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36377590

RESUMO

The major criterion that distinguishes eukaryotes from prokaryotes is the presence of organelles in the former. Organelles provide a compartment in which biochemical processes are corralled within bespoke biophysical conditions and act as storage depots, powerhouses, waste storage/recycling units and innate immune signalling hubs. A key challenge faced by organelles is to define, and then retain, their identity; this is mediated by complex proteostasis mechanisms including the import of an organelle-specific proteome, the exclusion of non-organellar proteins and the removal of misfolded proteins via dedicated quality control mechanisms. This Special Issue on Organelle Homeostasis provides an engaging, eclectic, yet integrative, perspective on organelle homeostasis in a range of organelles including those from the secretory and endocytic pathways, mitochondria, the autophagy-lysosomal pathway and the nucleus and its sub-compartments. Some lesser-known organelles including migrasomes (organelles that are released by migrating cells) and GOMED (a Golgi-specific form of autophagy) are also introduced. In the spirit of the principles of organelle biology, we hope you find the reviews in this Issue both encapsulating and captivating, and we thank the authors for their excellent contributions.


Assuntos
Retículo Endoplasmático , Organelas , Retículo Endoplasmático/metabolismo , Organelas/metabolismo , Complexo de Golgi/metabolismo , Lisossomos/metabolismo , Mitocôndrias , Homeostase
18.
Curr Opin Microbiol ; 70: 102226, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36332501

RESUMO

Members of the Apicomplexa phylum are unified by an apical complex tailored for motility and host cell invasion. It includes regulated secretory organelles and a conoid attached to the apical polar ring (APR) from which subpellicular microtubules emerge. In coccidia, the conoid is composed of a cone of spiraling tubulin fibers, two preconoidal rings, and two intraconoidal microtubules. The conoid extrudes through the APR in motile parasites. Recent advances in proteomics, cryo-electron tomography, super-resolution, and expansion microscopy provide a more comprehensive view of the spatial and temporal resolution of proteins belonging to the conoid subcomponents. In combination with the phenotyping of targeted mutants, the biogenesis, turnover, dynamics, and function of the conoid begin to be elucidated.


Assuntos
Apicomplexa , Toxoplasma , Toxoplasma/metabolismo , Apicomplexa/genética , Citoesqueleto/metabolismo , Microtúbulos/metabolismo , Organelas/metabolismo
19.
Proc Natl Acad Sci U S A ; 119(45): e2207402119, 2022 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-36322752

RESUMO

The intracellular metabolism of organelles, like lysosomes and mitochondria, is highly coordinated spatiotemporally and functionally. The activities of lysosomal enzymes significantly rely on the cytoplasmic temperature, and heat is constantly released by mitochondria as the byproduct of adenosine triphosphate (ATP) generation during active metabolism. Here, we developed temperature-sensitive LysoDots and MitoDots to monitor the in situ thermal dynamics of lysosomes and mitochondria. The design is based on upconversion nanoparticles (UCNPs) with high-density surface modifications to achieve the exceptionally high sensitivity of 2.7% K-1 and low uncertainty of 0.8 K for nanothermometry to be used in living cells. We show the measurement is independent of the ion concentrations and pH values. With Ca2+ ion shock, the temperatures of both lysosomes and mitochondria increased by ∼2 to 4 °C. Intriguingly, with chloroquine (CQ) treatment, the lysosomal temperature was observed to decrease by up to ∼3 °C, while mitochondria remained relatively stable. Lastly, with oxidative phosphorylation inhibitor treatment, we observed an ∼3 to 7 °C temperature increase and a thermal transition from mitochondria to lysosomes. These observations indicate different metabolic pathways and thermal transitions between lysosomes and mitochondria inside HeLa cells. The nanothermometry probes provide a powerful tool for multimodality functional imaging of subcellular organelles and interactions with high spatial, temporal, and thermal dynamics resolutions.


Assuntos
Lisossomos , Nanopartículas , Humanos , Temperatura , Células HeLa , Lisossomos/metabolismo , Organelas/metabolismo , Mitocôndrias/metabolismo
20.
Int J Mol Sci ; 23(21)2022 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-36362255

RESUMO

Mitochondrion-related organelles (MROs) are loosely defined as degenerated mitochondria in anaerobic and microaerophilic lineages. Opalinids are commonly regarded as commensals in the guts of cold-blooded amphibians. It may represent an intermediate adaptation stage between the conventional aerobic mitochondria and derived anaerobic MROs. In the present study, we sequenced and analyzed the MRO genome of Cepedea longa. It has a linear MRO genome with large inverted repeat gene regions at both ends. Compared to Blastocystis and Proteromonas lacertae, the MRO genome of C. longa has a higher G + C content and repeat sequences near the central region. Although three Opalinata species have different morphological characteristics, phylogenetic analyses based on eight concatenated nad genes indicate that they are close relatives. The phylogenetic analysis showed that C. longa clustered with P. lacertae with strong support. The 18S rRNA gene-based phylogeny resolved the Opalinea clade as a sister clade to Karotomorpha, which then further grouped with Proteromonas. The paraphyly of Proteromonadea needs to be verified due to the lack of MRO genomes for key species, such as Karotomorpha, Opalina and Protoopalina. Besides, our dataset and analyses offered slight support for the paraphyly of Bigyra.


Assuntos
Anuros , Estramenópilas , Animais , Filogenia , Anuros/genética , Estramenópilas/genética , Organelas/metabolismo , Mitocôndrias/genética
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