Strategies for maximizing ATP supply in the microsporidian Encephalitozoon cuniculi: direct binding of mitochondria to the parasitophorous vacuole and clustering of the mitochondrial porin VDAC

Microsporidia are obligate intracellular parasites with extremely reduced genomes and a dependence on host-derived ATP. The microsporidium Encephalitozoon cuniculi proliferates within a membranous vacuole and we investigated how the ATP supply is optimized at the vacuole–host interface. Using spatial EM quantification (stereology), we found a single layer of mitochondria coating substantial proportions of the parasitophorous vacuole. Mitochondrial binding occurred preferentially over the vegetative ‘meront’ stages of the parasite, which bulged into the cytoplasm, thereby increasing the membrane surface available for mitochondrial interaction. In a broken cell system mitochondrial binding was maintained and was typified by electron dense structures (<10 nm long) bridging between outer mitochondrial and vacuole membranes. In broken cells mitochondrial binding was sensitive to a range of protease treatments. The function of directly bound mitochondria, as measured by the membrane potential sensitive dye JC-1, was indistinguishable from other mitochondria in the cell although there was a generalized depression of the membrane potential in infected cells. Finally, quantitative immuno-EM revealed that the ATP-delivering mitochondrial porin, VDAC, was concentrated atthe mitochondria-vacuole interaction site. Thus E. cuniculi appears to maximize ATP supply by direct binding of mitochondria to the parasitophorous vacuole bringing this organelle within 0.020 microns of the growing vegetative form of the parasite. ATP-delivery is further enhanced by clustering of ATP transporting porins in those regions of the outer mitochondrial membrane lying closest to the parasite

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Article is devoted to the oil and gas situation in Russia. The article presents the forecasts of demand for natural gas, also referred to is not a stable situation in the country and Russian companies are struggling with these changes

Characterization of a protein of the plastid inner envelope having homology to animal inorganic phosphate, chloride and organic-anion transporters

A protein from Arabidopsis thaliana (L.) Heynh. showing homology to animal proteins of the NaPi-1 family, involved in the transport of inorganic phosphate, chloride, glutamate and sialic acid, has been characterized. This protein, named ANTR2 (for anion transporters) was shown by chloroplast subfractionation to be localized to the plastid inner envelope in both A. thaliana and Spinacia oleracea (L.). Immunolocalization revealed that ANTR2 was expressed in the leaf mesophyll cells as well as in the developing embryo at the upturned-U stage. Five additional homologues of ANTR2 are found in the Arabidopsis genome, of which one was shown by green fluorescent protein (GFP) fusion to be also located in the chloroplast. All ANTR proteins share homology to the animal NaPi-1 family, as well as to other organic-anion transporters that are members of the Anion:Cation Symporter (ACS) family, and share the main features of transporters from this family, including the presence of 12 putative transmembrane domains and of a 7-amino acid motif in the fourth putative transmembrane domain. ANTR2 thus represent a novel protein of the plastid inner envelope that is likely to be involved in anion transpor

An oxaloacetate decarboxylase homologue protein influences the intracellular survival of Legionella pneumophila

Legionella pneumophila is a facultative intracellular parasite which is able to survive in various eukaryotic cells. We characterised a Tn5-mutant of the L. pneumophila Corby strain and were able to identify the insertion site of the transposon. It is localised within an open reading frame which shows high homology to the α-subunit of the oxaloacetate decarboxylase (OadA) of Klebsiella pneumoniae. The OadA homologous protein of L. pneumophila was detected in the wild-type strain by Western blotting. Since the intracellular multiplication of the oadA− mutant strain is reduced in guinea pig alveolar macrophages and human monocytes, it is concluded that the oadA gene product has an effect on the intracellular survival of L. pneumophil

Erich Fromm and the Critical Theory of Communication

Erich Fromm (1900-1980) was a Marxist psychoanalyst, philosopher and socialist humanist. This paper asks: How can Fromm’s critical theory of communication be used and updated to provide a critical perspective in the age of digital and communicative capitalism? In order to provide an answer, the article discusses elements from Fromm’s work that allow us to better understand the human communication process. The focus is on communication (section 2), ideology (section 3), and technology (section 4). Fromm’s approach can inform a critical theory of communication in multiple respects: His notion of the social character allows to underpin such a theory with foundations from critical psychology. Fromm’s distinction between the authoritarian and the humanistic character can be used for discerning among authoritarian and humanistic communication. Fromm’s work can also inform ideology critique: The ideology of having shapes life, thought, language and social action in capitalism. In capitalism, technology (including computing) is fetishized and the logic of quantification shapes social relations. Fromm’s quest for humanist technology and participatory computing can inform contemporary debates about digital capitalism and its alternatives