Chapter 19 Macromolecular Movement into Mitochondria

Glaser, Elzbieta; Knorpp, Carina; Hugosson, Marie; E, von Stedingk

doi:10.1016/s0091-679x(08)61036-5

Cited by 11 publications

(7 citation statements)

References 24 publications

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“…Commercially purchased spinach green leaves were used as starting material. Mitochondria were partially purified using a standard procedure by differential centrifugation and Percoll density gradient centrifugation (27). Pure chloroplasts were isolated as previously described (28 -30).…”

Section: Methodsmentioning

confidence: 99%

“Respirasome”-like Supercomplexes in Green Leaf Mitochondria of Spinach

Krause

Reifschneider

Vocke

et al. 2004

Journal of Biological Chemistry

125

107

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Higher plant mitochondria have many unique features compared with their animal and fungal counterparts. This is to a large extent related to the close functional interdependence of mitochondria and chloroplasts, in which the two ATP-generating processes of oxidative phosphorylation and photosynthesis, respectively, take place. We show that digitonin treatment of mitochondria contaminated with chloroplasts from spinach (Spinacia oleracea) green leaves at two different buffer conditions, performed to solubilize oxidative phosphorylation supercomplexes, selectively extracts the mitochondrial membrane protein complexes and only low amounts of stroma thylakoid membrane proteins. By analysis of digitonin extracts from partially purified mitochondria of green leaves from spinach using blue and colorless native electrophoresis, we demonstrate for the first time that in green plant tissue a substantial proportion of the respiratory complex IV is assembled with complexes I and III into "respirasome"-like supercomplexes, previously observed in mammalian, fungal, and non-green plant mitochondria only. Thus, fundamental features of the supramolecular organization of the standard respiratory complexes I, III, and IV as a respirasome are conserved in all higher eukaryotes. Because the plant respiratory chain is highly branched possessing additional alternative enzymes, the functional implications of the occurrence of respiratory supercomplexes in plant mitochondria are discussed.

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Section: Methodsmentioning

confidence: 99%

“Respirasome”-like Supercomplexes in Green Leaf Mitochondria of Spinach

Krause

Reifschneider

Vocke

et al. 2004

Journal of Biological Chemistry

125

107

View full text Add to dashboard Cite

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“…Intact chloroplasts were isolated from 10-d-old pea leaves as described by Bruce et al (1994) and from potato (Solanum tuberosum) tuber mitochondria as described by Glaser et al (1995). Chloroplast and mitochondria import assays were carried out as described by Waegemann and Soll (1995) and Glaser et al (1995), respectively. The following precursor proteins were used as controls: soybean (Glycine max) AOX (Whelan et al, 1993) and, for pea, the small subunit of Rubisco (Anderson and Smith, 1986).…”

Section: Import Of Radiolabeled Proteins Into Isolated Mitochondria Amentioning

confidence: 99%

Mitochondrial and Nuclear Localization of a Novel Pea Thioredoxin: Identification of Its Mitochondrial Target Proteins

et al. 2009

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Plants contain several genes encoding thioredoxins (Trxs), small proteins involved in the regulation of the activity of many enzymes through dithiol-disulfide exchange. In addition to chloroplastic and cytoplasmic Trx systems, plant mitochondria contain a reduced nicotinamide adenine dinucleotide phosphate-dependent Trx reductase and a specific Trx o, and to date, there have been no reports of a gene encoding a plant nuclear Trx. We report here the presence in pea (Pisum sativum) mitochondria and nuclei of a Trx isoform (PsTrxo1) that seems to belong to the Trx o group, although it differs from this Trx type by its absence of introns in the genomic sequence. Western-blot analysis with isolated mitochondria and nuclei, immunogold labeling, and green fluorescent protein fusion constructs all indicated that PsTrxo1 is present in both cell compartments. Moreover, the identification by tandem mass spectrometry of the native mitochondrial Trx after gel filtration using the fast-protein liquid chromatography system of highly purified mitochondria and the in vitro uptake assay into isolated mitochondria also corroborated a mitochondrial location for this protein. The recombinant PsTrxo1 protein has been shown to be reduced more effectively by the Saccharomyces cerevisiae mitochondrial Trx reductase Trr2 than by the wheat (Triticum aestivum) cytoplasmic reduced nicotinamide adenine dinucleotide phosphate-dependent Trx reductase. PsTrxo1 was able to activate alternative oxidase, and it was shown to interact with a number of mitochondrial proteins, including peroxiredoxin and enzymes mainly involved in the photorespiratory process.

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“…Another control in such experiments involves the prior treatment of cells with N-Myr inhibitors, such as fumagillin (inhibits MetAP2) or 2hydroxymyristate, a potent inhibitor of N-Myr in animal cells [150,151]. For studies of LPR, in vitro-translated [ 35 ]S-labeled full-length proteins are generally used in isolated organelles, in the presence of high (3 mM) concentrations of ATP [152,153]. Cleavage is followed by means of time-course experiments and analyses of [ATP] dependence, a major criterion for cleavage specificity.…”

Section: Use Of Radioactive Precursorsmentioning

confidence: 99%

Tools for analyzing and predicting N‐terminal protein modifications

Meinnel

Giglione

2008

Proteomics

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The vast majority of the proteins encoded in any genome naturally undergo a large number of different N-terminal modifications, hindering their characterization by routine proteomic approaches. These modifications are often irreversible, usually cotranslational and are crucial, as their occurrence may reflect or affect the status, fate and function of the protein. For example, large signal peptide cleavages and N-blocking mechanisms reflect targeting to various cell compartments, whereas N-ligation events tend to be related to protein half-life. N-terminal positional proteomic strategies hold promise as a new generation of approaches to the fine analysis of such modifications. However, further biological investigation is required to resolve problems associated with particular low-abundance or challenging N-terminal modifications. Recent progress in genomics and bioinformatics has provided us with a means of assessing the impact of these modifications in proteomes. This review focuses on methods for characterizing the occurrence and diversity of N-terminal modifications and for assessing their contribution to function in complete proteomes. Progress is being made towards the annotation of databases containing information for complete proteomes, and should facilitate research into all areas of proteomics.

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Chapter 19 Macromolecular Movement into Mitochondria

Cited by 11 publications

References 24 publications

“Respirasome”-like Supercomplexes in Green Leaf Mitochondria of Spinach

“Respirasome”-like Supercomplexes in Green Leaf Mitochondria of Spinach

Mitochondrial and Nuclear Localization of a Novel Pea Thioredoxin: Identification of Its Mitochondrial Target Proteins

Tools for analyzing and predicting N‐terminal protein modifications

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