scholarly journals Identification of Novel Mitochondrial Protein Components ofChlamydomonas reinhardtii. A Proteomic Approach

2003 ◽  
Vol 132 (1) ◽  
pp. 318-330 ◽  
Author(s):  
Robert van Lis ◽  
Ariane Atteia ◽  
Guillermo Mendoza-Hernández ◽  
Diego González-Halphen
Keyword(s):  
Mitochondrial Protein ◽  
Proteomic Approach ◽  
Protein Components

Preparation of oligomycin-sensitive ATPase enriched submitochondrial fraction from beef heart mitochondria

1979 ◽  
Vol 44 (9) ◽  
pp. 2854-2860 ◽  
Author(s):  
Petr Svoboda ◽  
Zdeněk Drahota
Keyword(s):  
Specific Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Mitochondrial Protein ◽  
Sucrose Density Gradient ◽  
Heart Mitochondria ◽  
Beef Heart ◽  
Simple Method ◽  
Beef Heart Mitochondria ◽  
Relative Molecular Weight ◽  
Protein Components

A simple method for purification of oligomycin-sensitive ATPase from beef heart mitochondria is described. The isolation procedure is based on short term solubilization of mitochondrial membrane in deoxycholate and 1M-KCl followed by sequential precipitation of hydrofobic proteins and isopycnic centrifugation of crude particulate enzyme on sucrose density gradient. The oligomycin-sesitive ATPase preparation has a specific activity 15-20μmol P/min/mg protein and contains 5% of the total mitochondrial protein which can be separated by SDS-polyacrylamide gel electrophoresis into 13 protein components of relative molecular weight from 6 000 - 65 000 daltons, respectively.

scholarly journals MRPS25 mutations impair mitochondrial translation and cause encephalomyopathy

2019 ◽  
Vol 28 (16) ◽  
pp. 2711-2719 ◽  
Author(s):  
Enrico Bugiardini ◽  
Alice L Mitchell ◽  
Ilaria Dalla Rosa ◽  
Hue-Tran Horning-Do ◽  
Alan M Pitmann ◽  
...  
Keyword(s):  
Respiratory Chain ◽  
Mitochondrial Protein ◽  
In Silico Analysis ◽  
Small Subunit ◽  
Mitochondrial Translation ◽  
Transgenic Expression ◽  
Mitochondrial Ribosomes ◽  
Mitochondrial Ribosome ◽  
Protein Components ◽  
Biochemical Analyses

Abstract Mitochondrial disorders are clinically and genetically heterogeneous and are associated with a variety of disease mechanisms. Defects of mitochondrial protein synthesis account for the largest subgroup of disorders manifesting with impaired respiratory chain capacity; yet, only a few have been linked to dysfunction in the protein components of the mitochondrial ribosomes. Here, we report a subject presenting with dyskinetic cerebral palsy and partial agenesis of the corpus callosum, while histochemical and biochemical analyses of skeletal muscle revealed signs of mitochondrial myopathy. Using exome sequencing, we identified a homozygous variant c.215C>T in MRPS25, which encodes for a structural component of the 28S small subunit of the mitochondrial ribosome (mS25). The variant segregated with the disease and substitutes a highly conserved proline residue with leucine (p.P72L) that, based on the high-resolution structure of the 28S ribosome, is predicted to compromise inter-protein contacts and destabilize the small subunit. Concordant with the in silico analysis, patient’s fibroblasts showed decreased levels of MRPS25 and other components of the 28S subunit. Moreover, assembled 28S subunits were scarce in the fibroblasts with mutant mS25 leading to impaired mitochondrial translation and decreased levels of multiple respiratory chain subunits. Crucially, these abnormalities were rescued by transgenic expression of wild-type MRPS25 in the mutant fibroblasts. Collectively, our data demonstrate the pathogenicity of the p.P72L variant and identify MRPS25 mutations as a new cause of mitochondrial translation defect.

Altered mitochondrial morphology and defective protein import reveal novel roles for Bax and/or Bak in skeletal muscle

2013 ◽  
Vol 305 (5) ◽  
pp. C502-C511 ◽  
Author(s):  
Yuan Zhang ◽  
Sobia Iqbal ◽  
Michael F. N. O'Leary ◽  
Keir J. Menzies ◽  
Ayesha Saleem ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Mitochondrial Function ◽  
Protein Import ◽  
Mitochondrial Dynamics ◽  
Mitochondrial Protein ◽  
Heat Shock Protein 90 ◽  
Mitochondrial Morphology ◽  
Double Knockout ◽  
Mitochondrial Protein Import ◽  
Protein Components

The function Bax and/or Bak in constituting a gateway for mitochondrial apoptosis in response to apoptotic stimuli has been unequivocally demonstrated. However, recent work has suggested that Bax/Bak may have unrecognized nonapoptotic functions related to mitochondrial function in nonstressful environments. Wild-type (WT) and Bax/Bak double knockout (DKO) mice were used to determine alternative roles for Bax and Bak in mitochondrial morphology and protein import in skeletal muscle. The absence of Bax and/or Bak altered mitochondrial dynamics by regulating protein components of the organelle fission and fusion machinery. Moreover, DKO mice exhibited defective mitochondrial protein import, both into the matrix and outer membrane compartments, which was consistent with our observations of impaired membrane potential and attenuated expression of protein import machinery (PIM) components in intermyofibrillar mitochondria. Furthermore, the cytosolic chaperones heat-shock protein 90 (Hsp90) and binding immunoglobulin protein (BiP) were markedly increased with the deletion of Bax/Bak, indicating that the cytosolic environment related to protein folding may be changed in DKO mice. Interestingly, endurance training fully restored the deficiency of protein import in DKO mice, likely via the upregulation of PIM components and through improved cytosolic chaperone protein expression. Thus our results emphasize novel roles for Bax and/or Bak in mitochondrial function and provide evidence, for the first time, of a curative function of exercise training in ameliorating a condition of defective mitochondrial protein import.

scholarly journals Generation of a mitochondrial protein compendium in Dictyostelium discoideum

2021 ◽  
Author(s):  
Hong Xu
Keyword(s):  
Dictyostelium Discoideum ◽  
Mitochondrial Protein ◽  
Metabolic Reprogramming ◽  
Mitochondrial Proteins ◽  
Mitochondrial Proteome ◽  
Cellular Processes ◽  
Proteomic Approach ◽  
The Social ◽  
Cellular Pathways ◽  
Alpha Proteobacteria

The social amoeba Dictyostelium discoideum is a well-established model to study numerous cellular processes including cell motility, chemotaxis, and differentiation. As energy metabolism is involved in these processes, mitochondrial genetics and bioenergetics are of interest, though many features of Dictyostelium mitochondria differ from metazoans. A comprehensive inventory of mitochondrial proteins is critical to understanding mitochondrial processes and their involvement in various cellular pathways. Here, we utilized high-throughput multiplexed protein quantitation and homology analyses to generate a high-confidence mitochondrial protein compendium. Our proteomic approach, which utilizes quantitative mass spectrometry in combination with mathematical modeling, was validated through mitochondrial targeting sequence prediction and live-cell imaging. Our final compendium consists of 1082 proteins. Within our D. discoideum mitochondrial proteome, we identify many proteins that are not present in humans, yeasts, or the ancestral alpha-proteobacteria, which can serve as a foundation for future investigations into the unique mitochondria of Dictyostelium. Additionally, we leverage our compendium to highlight the complexity of metabolic reprogramming during starvation-induced development. Our compendium lays a foundation to investigate mitochondrial processes that are unique in protists, as well as for future studies to understand the functions of conserved mitochondrial proteins in health and diseases using D. discoideum as the model.

scholarly journals 388 MITOCHONDRIAL PROTEIN ALTERATIONS IN HUMAN ARTICULAR CHONDROCYTES REVEALED BY A PROTEOMIC APPROACH

2007 ◽  
Vol 15 ◽  
pp. C212-C213
Author(s):  
C. Ruiz-Romero ◽  
V. Carreira ◽  
S. Remeseiro ◽  
V. Calamia ◽  
J. Mateos ◽  
...  
Keyword(s):  
Articular Chondrocytes ◽  
Mitochondrial Protein ◽  
Human Articular Chondrocytes ◽  
Proteomic Approach ◽  
Protein Alterations

scholarly journals Regulation of mitochondrial protein turnover by thyroid hormone(s)

1975 ◽  
Vol 152 (2) ◽  
pp. 379-387 ◽  
Author(s):  
Medha S. Rajwade ◽  
Surendra S. Katyare ◽  
Prema Fatterpaker ◽  
Arunachala Sreenivasan
Keyword(s):  
Thyroid Hormone ◽  
Protein Turnover ◽  
Mitochondrial Protein ◽  
Brain Mitochondria ◽  
Mitochondrial Proteins ◽  
Proteinase Activity ◽  
Turnover Rates ◽  
Kidney Mitochondria ◽  
Liver And Kidney ◽  
Protein Components

1. The effect of thyroidectomy on turnover rates of liver, kidney and brain mitochondrial proteins was examined. 2. In the euthyroid state, liver and kidney mitochondria show a synchronous turnover with all protein components showing more or less identical half-lives compared with the whole mitochondria. The brain mitochondrial proteins show asynchronous turnover, the soluble proteins having shorter half-lives. 3. Mitochondrial DNA (m-DNA) of liver and kidney has half-lives comparable with that of whole mitochondria from these tissues. 4. Thyroidectomy results in increased half-lives of liver and kidney mitochondria, with no apparent change in the half-life of brain mitochondria. 5. A detailed investigation of the turnover rates of several protein components revealed a significant decrease in the turnover rates of mitochondrial insoluble proteins from the three tissues under study. 6. The turnover rates of m-DNA of liver and kidney show a parallel decrease. 7. Thus it is apparent that thyroid hormone(s) may have a regulatory role in maintaining the synchrony of turnover of liver and kidney mitochondria in the euthyroid state. Turnover of brain mitochondria may perhaps be regulated by some other factor(s) in addition to thyroid hormone(s). 8. It seems likely that during mitochondrial turnover m-DNA and insoluble proteins may constitute a major unit. 9. The mitochondrial protein contents of the three tissues are not affected by thyroidectomy. 10. No correlation was seen between the turnover rate of mitochondria and cathepsin activity in any of the tissues under study in normal or thyroidectomized animals. 11. On the other hand, mitochondrial proteinase activity shows good correlation with the turnover rates of mitochondria in normal animals, and a parallel decrease in activity comparable with the decreased rates of turnover is observed after thyroidectomy. 12. It is concluded that mitochondrial proteinase activity may play a significant role in their protein turnover.

scholarly journals Generation of a Mitochondrial Protein Compendium in Dictyostelium Discoideum

2021 ◽  
Author(s):  
Anna V Freitas ◽  
Jake T Herb ◽  
Miao Pan ◽  
Yong Cheng ◽  
Marjan Gucek ◽  
...  
Keyword(s):  
Dictyostelium Discoideum ◽  
Mitochondrial Protein ◽  
Metabolic Reprogramming ◽  
Mitochondrial Proteins ◽  
Mitochondrial Proteome ◽  
Cellular Processes ◽  
Proteomic Approach ◽  
The Social ◽  
Cellular Pathways ◽  
Alpha Proteobacteria

Abstract The social amoeba Dictyostelium discoideum is a well-established model to study numerous cellular processes including cell motility, chemotaxis, and differentiation. As energy metabolism is involved in these processes, mitochondrial genetics and bioenergetics are of interest, though many features of Dictyostelium mitochondria differ from metazoans. A comprehensive inventory of mitochondrial proteins is critical to understanding mitochondrial processes and their involvement in various cellular pathways. Here, we utilized high-throughput multiplexed protein quantitation and homology analyses to generate a high-confidence mitochondrial protein compendium. Our proteomic approach, which utilizes quantitative mass spectrometry in combination with mathematical modeling, was validated through mitochondrial targeting sequence prediction and live-cell imaging. Our final compendium consists of 1082 proteins. Within our D. discoideum mitochondrial proteome, we identify many proteins that are not present in humans, yeasts, or the ancestral alpha-proteobacteria, which can serve as a foundation for future investigations into the unique mitochondria of Dictyostelium. Additionally, we leverage our compendium to highlight the complexity of metabolic reprogramming during starvation-induced development. Our compendium lays a foundation to investigate mitochondrial processes that are unique in protists, as well as for future studies to understand the functions of conserved mitochondrial proteins in health and diseases using D. discoideum as the model.

scholarly journals Pulse-chase SILAC–based analyses reveal selective oversynthesis and rapid turnover of mitochondrial protein components of respiratory complexes

2020 ◽  
Vol 295 (9) ◽  
pp. 2544-2554 ◽  
Author(s):  
Daniel F. Bogenhagen ◽  
John D. Haley
Keyword(s):  
Nuclear Dna ◽  
Isotope Labeling ◽  
Mitochondrial Protein ◽  
Cluster Assembly ◽  
Mitochondrial Ribosomes ◽  
Mammalian Mitochondria ◽  
The Matrix ◽  
Assembly Kinetics ◽  
Rieske Fes Protein ◽  
Protein Components

Mammalian mitochondria assemble four complexes of the respiratory chain (RCI, RCIII, RCIV, and RCV) by combining 13 polypeptides synthesized within mitochondria on mitochondrial ribosomes (mitoribosomes) with over 70 polypeptides encoded in nuclear DNA, translated on cytoplasmic ribosomes, and imported into mitochondria. We have previously observed that mitoribosome assembly is inefficient because some mitoribosomal proteins are produced in excess, but whether this is the case for other mitochondrial assemblies such as the RCs is unclear. We report here that pulse-chase stable isotope labeling with amino acids in cell culture (SILAC) is a valuable technique to study RC assembly because it can reveal considerable differences in the assembly rates and efficiencies of the different complexes. The SILAC analyses of HeLa cells indicated that assembly of RCV, comprising F1/Fo-ATPase, is rapid with little excess subunit synthesis, but that assembly of RCI (i.e. NADH dehydrogenase) is far less efficient, with dramatic oversynthesis of numerous proteins, particularly in the matrix-exposed N and Q domains. Unassembled subunits were generally degraded within 3 h. We also observed differential assembly kinetics for individual complexes that were immunoprecipitated with complex-specific antibodies. Immunoprecipitation with an antibody that recognizes the ND1 subunit of RCI co-precipitated a number of proteins implicated in FeS cluster assembly and newly synthesized ubiquinol-cytochrome c reductase Rieske iron-sulfur polypeptide 1 (UQCRFS1), the Rieske FeS protein in RCIII, reflecting some coordination between RCI and RCIII assemblies. We propose that pulse-chase SILAC labeling is a useful tool for studying rates of protein complex assembly and degradation.

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