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The Journal of Eukaryotic Microbiology Jul 2022The alternative oxidase (AOX) is a protein involved in supporting enzymatic reactions of the Krebs cycle in instances when the canonical (cytochrome-mediated)...
The alternative oxidase (AOX) is a protein involved in supporting enzymatic reactions of the Krebs cycle in instances when the canonical (cytochrome-mediated) respiratory chain has been inhibited, while allowing for the maintenance of cell growth and necessary metabolic processes for survival. Among eukaryotes, alternative oxidases have dispersed distribution and are found in plants, fungi, and protists, including Naegleria ssp. Naegleria species are free-living unicellular amoeboflagellates and include the pathogenic species of N. fowleri, the so-called "brain-eating amoeba." Using a multidisciplinary approach, we aimed to understand the evolution, localization, and function of AOX and the role that plays in Naegleria's biology. Our analyses suggest that AOX was present in last common ancestor of the genus and structure prediction showed that all functional residues are also present in Naegleria species. Using cellular and biochemical techniques, we also functionally characterize N. gruberi's AOX in its mitochondria, and we demonstrate that its inactivation affects its proliferation. Consequently, we discuss the benefits of the presence of this protein in Naegleria species, along with its potential pathogenicity role in N. fowleri. We predict that our findings will spearhead new explorations to understand the cell biology, metabolism, and evolution of Naegleria and other free-living relatives.
Topics: Eukaryota; Mitochondrial Proteins; Naegleria; Naegleria fowleri; Oxidoreductases; Plant Proteins
PubMed: 35322502
DOI: 10.1111/jeu.12908 -
Pharmaceutical Patent Analyst May 2021
Topics: Naegleria fowleri
PubMed: 34076529
DOI: 10.4155/ppa-2020-0023 -
Current Biology : CB May 2023Eukaryotic cells can undergo chemorepulsion, but the molecular mechanisms behind this phenomenon have remained unclear. Using Dictyostelium cells, a new study shows that...
Eukaryotic cells can undergo chemorepulsion, but the molecular mechanisms behind this phenomenon have remained unclear. Using Dictyostelium cells, a new study shows that competition of two ligands for the same receptors results in chemorepulsion, thus revealing a simple rule for eukaryotic cells to achieve negative chemotaxis.
Topics: Chemotaxis; Dictyostelium; Eukaryotic Cells
PubMed: 37160099
DOI: 10.1016/j.cub.2023.03.076 -
BioEssays : News and Reviews in... Apr 2021Ancient pathways promoting unicellularity and multicellularity are associated with cancer, the former being pro-oncogenic and the latter acting to suppress oncogenesis.... (Review)
Review
Ancient pathways promoting unicellularity and multicellularity are associated with cancer, the former being pro-oncogenic and the latter acting to suppress oncogenesis. However, there are only a limited number of non-vertebrate models for studying these pathways. Here, we review Dictyostelium discoideum and describe how it can be used to understand these gene networks. D. discoideum has a unicellular and multicellular life cycle, making it possible to study orthologs of cancer-associated genes in both phases. During development, differentiated amoebae form a fruiting body composed of a mass of spores that are supported atop a stalk. A portion of the cells sacrifice themselves to become non-reproductive stalk cells. Cheating disrupts the principles of multicellularity, as cheater cells alter their cell fate to preferentially become spores. Importantly, D. discoideum has gene networks and several strategies for maintaining multicellularity. Therefore, D. discoideum can help us better understand how conserved genes and pathways involved in multicellularity also influence cancer development, potentially identifying new therapeutic avenues.
Topics: Amoeba; Cell Differentiation; Dictyostelium; Humans; Neoplasms
PubMed: 33448043
DOI: 10.1002/bies.202000156 -
Methods in Molecular Biology (Clifton,... 2022The unicellular eukaryotic amoeba, Dictyostelium discoideum, represents a superb model for examining the molecular mechanism of chemotaxis. Under vegetative conditions,...
The unicellular eukaryotic amoeba, Dictyostelium discoideum, represents a superb model for examining the molecular mechanism of chemotaxis. Under vegetative conditions, the amoebae are chemotactically responsive to pterins, such as folic acid. Under starved conditions, they lose their sensitivity to pterins and become chemotactically responsive to cAMP. As an NIH model system, Dictyostelium offers a variety of advantages in studying chemotaxis, including ease of growth, genetic tractability, and the conservation of mammalian signaling pathways. In this chapter, we describe the use of the under-agarose chemotaxis assay to understand the signaling pathways controlling directional sensing and motility in Dictyostelium discoideum. Given the similarities between Dictyostelium and mammalian cells, this allows us to dissect conserved pathways involved in eukaryotic chemotaxis.
Topics: Amoeba; Animals; Chemotaxis; Cyclic AMP; Dictyostelium; Pterins; Sepharose
PubMed: 34542861
DOI: 10.1007/978-1-0716-1661-1_16 -
Biological Reviews of the Cambridge... Oct 2019Dictyostelium discoideum and the other dictyostelid slime moulds ('social amoebae') are popular model organisms best known for their demonstration of sorocarpic... (Review)
Review
Dictyostelium discoideum and the other dictyostelid slime moulds ('social amoebae') are popular model organisms best known for their demonstration of sorocarpic development. In this process, many cells aggregate to form a multicellular unit that ultimately becomes a fruiting body bearing asexual spores. Several other unrelated microorganisms undergo comparable processes, and in some it is evident that their multicellular development evolved from the differentiation process of encystation. While it has been argued that the dictyostelid fruiting body had similar origins, it has also been proposed that dictyostelid sorocarpy evolved from the unicellular fruiting process found in other amoebozoan slime moulds. This paper reviews the developmental biology of the dictyostelids and other relevant organisms and reassesses the two hypotheses on the evolutionary origins of dictyostelid development. Recent advances in phylogeny, genetics, and genomics and transcriptomics indicate that further research is necessary to determine whether or not the fruiting bodies of the dictyostelids and their closest relatives, the myxomycetes and protosporangids, are homologous.
Topics: Biological Evolution; Dictyostelium; Fruiting Bodies, Fungal; Phylogeny; Spores, Fungal
PubMed: 30989827
DOI: 10.1111/brv.12516 -
The Korean Journal of Parasitology Aug 2022The high percentage of Vermamoeba was found in tap water in Korea. This study investigated whether Vermamoeba induced allergic airway inflammation in mice. We selected 2...
The high percentage of Vermamoeba was found in tap water in Korea. This study investigated whether Vermamoeba induced allergic airway inflammation in mice. We selected 2 free-living amoebas (FLAs) isolated from tap water, which included Korean FLA 5 (KFA5; Vermamoeba vermiformis) and 21 (an homolog of Acanthamoeba lugdunensis KA/ E2). We axenically cultured KFA5 and KFA21. We applied approximately 1 × 106 to mice's nasal passages 6 times and investigated their pathogenicity. The airway resistance value was significantly increased after KFA5 and KFA21 treatments. The eosinophil recruitment and goblet cell hyperplasia were concomitantly observed in bronchial alveolar lavage (BAL) fluid and lung tissue in mice infected with KFA5 and KFA21. These infections also activated the Th2-related interleukin 25, thymic stromal lymphopoietin, and thymus and activation-regulated chemokines gene expression in mouse lung epithelial cells. The CD4+ interleukin 4+ cell population was increased in the lung, and the secretion of Th2-, Th17-, and Th1-associated cytokines were upregulated during KFA5 and KFA21 infection in the spleen, lung-draining lymph nodes, and BAL fluid. The pathogenicity (allergenicity) of KFA5 and KFA21 might not have drastically changed during the long-term in vitro culture. Our results suggested that Vermamoeba could elicit allergic airway inflammation and may be an airway allergen.
Topics: Acanthamoeba; Amoeba; Animals; Bronchoalveolar Lavage Fluid; Eosinophils; Inflammation; Mice; Water
PubMed: 36041484
DOI: 10.3347/kjp.2022.60.4.229 -
BMC Research Notes Apr 2020The amoeba Dictyostelium discoideum has been a valuable model organism to study numerous facets of eukaryotic cell biology, such as cell motility, cell adhesion,...
OBJECTIVE
The amoeba Dictyostelium discoideum has been a valuable model organism to study numerous facets of eukaryotic cell biology, such as cell motility, cell adhesion, macropinocytosis and phagocytosis, host-pathogen interactions and multicellular development. However, the relative small size of the Dictyostelium community hampers the production and distribution of reagents and tools, such as antibodies, by commercial vendors.
RESULTS
For the past 5 years, our laboratory has worked to promote an increased use of recombinant antibodies (rAbs) by academic laboratories. Here we report our efforts to ensure that Dictyostelium researchers have access to rAbs. Using hybridoma sequencing and phage display techniques, we generated a panel of recombinant antibodies against D. discoideum antigens, providing a useful and reliable set of reagents for labelling and characterization of proteins and subcellular compartments in D. discoideum, accessible to the entire Dictyostelium community.
Topics: Antibodies; Dictyostelium; Hybridomas; Models, Biological; Recombinant Proteins
PubMed: 32276653
DOI: 10.1186/s13104-020-05048-8 -
Infectious Disorders Drug Targets 2020Swine species are an important source of meat production worldwide, except in Islamic countries where pig breeding and pork consumption are forbidden. Hence, they are... (Review)
Review
BACKGROUND
Swine species are an important source of meat production worldwide, except in Islamic countries where pig breeding and pork consumption are forbidden. Hence, they are often neglected in these regions. A considerable number of wild boars (Sus scrofa) inhabit Iranian territories, particularly in dense forests of north, west and southwest of the country, but our knowledge regarding their parasites is very limited.
OBJECTIVE
The lack of a comprehensive record in this connection encouraged us to review the whole works of literature in the country.
METHODS
The current review presents all the information about the parasitic diseases of wild boar in Iran extracted from articles available in both Persian and English databases until June 2017.
RESULTS
So far, 8 genera of protozoa (Toxoplasma, Balanthidium, Tritrichomonas, Blastocystis, Entamoeba, Iodamoeba, Chilomastix and Sarcocystis) and 20 helminth species, including four cestode species, two trematode species, thirteen nematode species as well as a single species of Acanthocephala have been described in Iranian wild boars.
CONCLUSION
This review sheds light on the veterinary and public health aspects of the parasitic diseases of wild boars in the country and alerts authorities for future preventive measures.
Topics: Alveolata; Amoebozoa; Animals; Helminthiasis, Animal; Helminths; Iran; Protozoan Infections, Animal; Sus scrofa; Swine; Swine Diseases
PubMed: 31322074
DOI: 10.2174/1871526519666190716121824 -
BMC Microbiology Dec 2022Myxomycetes are a group of eukaryotes belonging to Amoebozoa, which are characterized by a distinctive life cycle, including the plasmodium stage and fruit body stage....
BACKGROUND
Myxomycetes are a group of eukaryotes belonging to Amoebozoa, which are characterized by a distinctive life cycle, including the plasmodium stage and fruit body stage. Plasmodia are all found to be associated with bacteria. However, the information about bacteria diversity and composition in different plasmodia was limited. Therefore, this study aimed to investigate the bacterial diversity of plasmodia from different myxomycetes species and reveal the potential function of plasmodia-associated bacterial communities.
RESULTS
The bacterial communities associated with the plasmodia of six myxomycetes (Didymium iridis, Didymium squamulosum, Diderma hemisphaericum, Lepidoderma tigrinum, Fuligo leviderma, and Physarum melleum) were identified by 16S rRNA amplicon sequencing. The six plasmodia harbored 38 to 52 bacterial operational taxonomic units (OTUs) that belonged to 7 phyla, 16 classes, 23 orders, 40 families, and 53 genera. The dominant phyla were Bacteroidetes, Firmicutes, and Proteobacteria. Most OTUs were shared among the six myxomycetes, while unique bacteria in each species only accounted for a tiny proportion of the total OTUs.
CONCLUSIONS
Although each of the six myxomycetes plasmodia had different bacterial community compositions, a high similarity was observed in the plasmodia-associated bacterial communities' functional composition. The high enrichment for gram-negative (> 90%) and aerobic (> 99%) bacteria in plasmodia suggest that myxomycetes may positively recruit certain kinds of bacteria from the surrounding environment.
Topics: Humans; Myxomycetes; RNA, Ribosomal, 16S; Physarum; Bacteria; Plasmodium
PubMed: 36544088
DOI: 10.1186/s12866-022-02725-5