GRSF1 regulates RNA processing in mitochondrial RNA granules.

Various specialized domains have been described in the cytosol and the nucleus; however, little is known about compartmentalization within the mitochondrial matrix. GRSF1 (G-rich sequence factor 1) is an RNA binding protein that was previously reported to localize in the cytosol. We found that an isoform of GRSF1 accumulates in discrete foci in the mitochondrial matrix. These foci are composed of nascent mitochondrial RNA and also contain RNase P, an enzyme that participates in mitochondrial RNA processing. GRSF1 was found to interact with RNase P and to be required for processing of both classical and tRNA-less RNA precursors. In its absence, cleavage of primary RNA transcripts is abnormal, leading to decreased expression of mitochondrially encoded proteins and mitochondrial dysfunction. Our findings suggest that the foci containing GRSF1 and RNase P correspond to sites where primary RNA transcripts converge to be processed. We have termed these large ribonucleoprotein structures "mitochondrial RNA granules.

Political economy of oil production from 1850s to 1974

A study of the oil industry in its modern development from the 1850s to 1973. During this period the industry underwent significant changes in terms of its productive expansion, the diversity of its products, its role in general production, its corporate organisation and in terms of its significance to the very reproduction of advanced societies. The examination of the oil industry focuses on a political economy of its historical expansion. The thesis uses a Marxist theoretical framework to examine issues related to oil production as well as synthesising the elemental features of oil production into a structured conceptual model of the oil industry. The thesis divides the analysis of oil between chapters dealing with economic and political concerns in the context of historic epochs. The economic components of the thesis deal with the capitalist development of oil, its relationship with other sectors of production and consumption and an assessment of its role in economic growth as a whole. This provides the basis for the subsequent politically focused analyses. The political chapters deal with two primary issues, including the state response to the monopolisation of the oil industry and the effect of the expanding importance of oil on political relations. The analysis of the monopolisation of the oil industry provides an opportunity to study the relationship between the state in a regulatory function and the subsequent constraint on oil industry autonomy. The study of interstate relations focuses in turn on the effect of expanding oil production on the economic interests of states, in their support for the reproduction of capital in their domains

DNA import competence and mitochondrial genetics

Aim. To understand the mechanism(s) underlying mitochondrial competence for DNA uptake and to exploit these pathways for the development of in vivo models of gene therapy. Methods. DNA uptake into isolated mitochondria from plant or from mutant Saccharomyces cerevisiae defective for mitochondrial proteins and carriers, biochemical approaches and transfection of mammalian cells with DNA bound to mitochondriotropic liposomes. Results. Special focus on the inner membrane showed the involvement of isoforms of the adenine nucleotide translocator and the contribution of proteins controlling mitochondrial morphology in DNA uptake into yeast organelles. Transfection assays led to significant incorporation of a mitochondrial construct into mammalian cells and expression of a marker gene. Conclusions. The data imply that there are multiple mitochondrial DNA import pathways. On the other hand, preliminary results suggest that mitochondriotropic liposomes can deliver DNA to mitochondria in live mammalian cells.Мета. Визначити механізми поглинання ДНК мітохондріями і використати їх для удосконалення існуючих моделей генної терапії in vivo. Методи. Поглинання ДНК ізольованими мітохондріями рослин або мітохондріями мутантних ліній Saccharomyces cerevisiae, дефектних за мітохондріальними білками та переносниками, біохімічні підходи і трансфекція в клітини ссавців ДНК, зв’язаної з мітохондріотропними ліпосомами. Результати. Основним підсумком вивчення внутрішньої мембрани виявилося встановлення того факта, що до процесу перенесення ДНК дріжджовими органелами залучені кілька ізоформ аденіннуклеотидтранслокази, а також білки, які контролюють мітохондріальну морфологію. В експериментах з трансфекції ДНК у клітини ссавців виявлено вбудовування в них мітохондріальної конструкції і експресію маркерного гена. Висновки. Отримані дані дозволяють припустити існування декількох механизмів імпорту ДНК у мітохондрії. Проте є попередні результати, які показують, що мітохондріотропні ліпосоми можуть бути використані для доставки ДНК у мітохондрії клітин ссавців in vivo.Цель. Выяснить механизмы поглощения ДНК митохондриями и использовать их для усовершенствования существующих моделей генной терапии in vivo. Методы. Поглощение ДНК изолированными митохондриями растений или митохондриями мутантных линий Saccharomyces cerevisiae, дефектных по митохондриальным белкам и переносчикам, биохимические подходы и трансфекция в клетки млекопитающих ДНК, связанной с митохондриотропными липосомами. Результаты. Основным итогом изучения внутренней мембраны оказалось установление того факта, что в процесс переноса ДНК дрожжевыми органеллами вовлечены несколько изоформ адениннуклеотидтранслоказы, а также белки, контролирующие митохондриальную морфологию. В экспериментах по трансфекции ДНК в клетки млекопитающих выявлены встраивание в них митохондриальной конструкции и экспрессию маркерного гена. Выводы. Полученные данные позволяют предположить существование нескольких механизмов импорта ДНК в митохондрии. Однако есть предварительные результаты, показывающие, что митохондриотропные липосомы могут быть использованы для доставки ДНК в митохондрии клеток млекопитающих in vivo

Mitochondrial transfection for studying organellar DNA repair, genome maintenance and aging

International audienc

Analysis of 953 human proteins from a mitochondrial HEK293 fraction by complexome profiling

Contains fulltext : 128506.pdf (publisher's version ) (Open Access)Complexome profiling is a novel technique which uses shotgun proteomics to establish protein migration profiles from fractionated blue native electrophoresis gels. Here we present a dataset of blue native electrophoresis migration profiles for 953 proteins by complexome profiling. By analysis of mitochondrial ribosomal complexes we demonstrate its potential to verify putative protein-protein interactions identified by affinity purification-mass spectrometry studies. Protein complexes were extracted in their native state from a HEK293 mitochondrial fraction and separated by blue native gel electrophoresis. Gel lanes were cut into gel slices of even size and analyzed by shotgun proteomics. Subsequently, the acquired protein migration profiles were analyzed for co-migration via hierarchical cluster analysis. This dataset holds great promise as a comprehensive resource for de novo identification of protein-protein interactions or to underpin and prioritize candidate protein interactions from other studies. To demonstrate the potential use of our dataset we focussed on the mitochondrial translation machinery. Our results show that mitoribosomal complexes can be analyzed by blue native gel electrophoresis, as at least four distinct complexes. Analysis of these complexes confirmed that 24 proteins that had previously been reported to co-purify with mitoribosomes indeed co-migrated with subunits of the mitochondrial ribosome. Co-migration of several proteins involved in biogenesis of inner mitochondrial membrane complexes together with mitoribosomal complexes suggested the possibility of co-translational assembly in human cells. Our data also highlighted a putative ribonucleotide complex that potentially contains MRPL10, MRPL12 and MRPL53 together with LRPPRC and SLIRP

A truncating<em> PET100</em> variant causing fatal infantile lactic acidosis and isolated cytochrome <em>c</em> oxidase deficiency.

Isolated mitochondrial complex IV (cytochrome c oxidase) deficiency is an important cause of mitochondrial disease in children and adults. It is genetically heterogeneous, given that both mtDNA-encoded and nuclear-encoded gene products contribute to structural components and assembly factors. Pathogenic variants within these proteins are associated with clinical variability ranging from isolated organ involvement to multisystem disease presentations. Defects in more than 10 complex IV assembly factors have been described including a recent Lebanese founder mutation in PET100 in patients presenting with Leigh syndrome. We report the clinical and molecular investigation of a patient with a fatal, neonatal-onset isolated complex IV deficiency associated with multiorgan involvement born to consanguineous, first-cousin British Asian parents. Exome sequencing revealed a homozygous truncating variant (c.142C&gt;T, p.(Gln48*)) in the PET100 gene that results in a complete loss of enzyme activity and assembly of the holocomplex. Our report confirms PET100 mutation as an important cause of isolated complex IV deficiency outside of the Lebanese population, extending the phenotypic spectrum associated with abnormalities within this gene