scholarly journals Differences in the products of mitochondrial protein synthesis in vivo in human and mouse cells and their potential use as markers for the mitochondrial genome in human–mouse cell hybrids

1974 ◽  
Vol 144 (1) ◽  
pp. 161-164 ◽  
Author(s):  
Alec Jeffreys ◽  
Ian Craig
Keyword(s):  
Protein Synthesis ◽  
Mitochondrial Protein ◽  
Detailed Comparison ◽  
Cell Types ◽  
Mouse Cell ◽  
Human Cells ◽  
Mitochondrial Protein Synthesis ◽  
Cell Hybrids ◽  
Different Cell Types

The proteins synthesized in the mitochondria of mouse and human cells grown in tissue culture were examined by electrophoresis in polyacrylamide gels. The proteins were labelled by incubating the cells in the presence of [35S]methionine and an inhibitor of cytoplasmic protein synthesis (emetine or cycloheximide). A detailed comparison between the labelled products of mouse and human mitochondrial protein synthesis was made possible by developing radioautograms after exposure to slab-electrophoresis gels. Patterns obtained for different cell types of the same species were extremely similar, whereas reproducible differences were observed on comparison of the profiles obtained for mouse and human cells. Four human–mouse somatic cell hybrids were examined, and in each one only components corresponding to mouse mitochondrially synthesized proteins were detected.

Mitochondrial protein synthesis in interspecific somatic cell hybrids

1986 ◽  
Vol 12 (5) ◽  
pp. 449-458 ◽  
Author(s):  
S. H. Zuckerman ◽  
F. P. Gillespie ◽  
J. F. Solus ◽  
R. Rybczynski ◽  
J. M. Eisenstadt
Keyword(s):  
Protein Synthesis ◽  
Somatic Cell ◽  
Mitochondrial Protein ◽  
Mitochondrial Protein Synthesis ◽  
Somatic Cell Hybrids ◽  
Cell Hybrids

scholarly journals THE INTRACELLULAR SITE OF SYNTHESIS OF MITOCHONDRIAL RIBOSOMAL PROTEINS IN NEUROSPORA CRASSA

1972 ◽  
Vol 54 (1) ◽  
pp. 56-74 ◽  
Author(s):  
Paul M. Lizardi ◽  
David J. L. Luck
Keyword(s):  
Protein Synthesis ◽  
Isoelectric Focusing ◽  
Gel Electrophoresis ◽  
Ribosomal Proteins ◽  
Mitochondrial Protein ◽  
Selective Inhibitor ◽  
Mitochondrial Protein Synthesis ◽  
Ribosomal Subunits

The intracellular site of synthesis of mitochondrial ribosomal proteins (MRP) in Neurospora crassa has been investigated using three complementary approaches. (a) Mitochondrial protein synthesis in vitro: Tritium-labeled proteins made by isolated mitochondria were compared to 14C-labeled marker MRP by cofractionation in a two-step procedure involving isoelectric focusing and polyacrylamide gel electrophoresis. Examination of the electrophoretic profiles showed that essentially none of the peaks of in vitro product corresponded exactly to any of the MRP marker peaks. (b) Sensitivity of in vivo MRP synthesis to chloramphenicol: Cells were labeled with leucine-3H in the presence of chloramphenicol, mitochondrial ribosomal subunits were subsequently isolated, and their proteins fractionated by isoelectric focusing followed by gel electrophoresis. The labeling of every single MRP was found to be insensitive to chloramphenicol, a selective inhibitor of mitochondrial protein synthesis. (c) Sensitivity of in vivo MRP synthesis to anisomycin: We have found this antibiotic to be a good selective inhibitor of cytoplasmic protein synthesis in Neurospora. In the presence of anisomycin the labeling of virtually all MRP is inhibited to the same extent as the labeling of cytoplasmic ribosomal proteins. On the basis of these three types of studies we conclude that most if not all 53 structural proteins of mitochondrial ribosomal subunits in Neurospora are synthesized by cytoplasmic ribosomes.

Glutamyl-tRNAGln amidotransferase is essential for mammalian mitochondrial translation in vivo

2014 ◽  
Vol 460 (1) ◽  
pp. 91-101 ◽  
Author(s):  
Lucía Echevarría ◽  
Paula Clemente ◽  
Rosana Hernández-Sierra ◽  
María Esther Gallardo ◽  
Miguel A. Fernández-Moreno ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Mammalian Cells ◽  
Mitochondrial Protein ◽  
Mitochondrial Protein Synthesis ◽  
Indirect Pathway ◽  
Mitochondrial Translation

We have demonstrated that in mitochondria of mammalian cells the aminoacylation of tRNAGln is produced by an indirect pathway involving the enzyme glutamyl-tRNAGln amidotransferase. Misaminoacylated Glu-tRNAGln is rejected from the ribosomes maintaining the fidelity of the mitochondrial protein synthesis.

Nuclear Inheritance of Erythromycin Resistance in Human Cells: New Class of Mitochondrial Protein Synthesis Mutants

1982 ◽  
Vol 2 (6) ◽  
pp. 694-700
Author(s):  
Claus-Jens Doersen ◽  
Eric J. Stanbridge
Keyword(s):  
Protein Synthesis ◽  
Hela Cells ◽  
Mitochondrial Protein ◽  
Human Cells ◽  
Recessive Trait ◽  
Mitochondrial Protein Synthesis ◽  
Erythromycin Resistance ◽  
New Class ◽  
Resistant Mutants

The characterization of two new erythromycin-resistant mutants of HeLa cells is described. The strains ERY2305 and ERY2309 both exhibited resistance to erythromycin in growth assays and cell-free mitochondrial protein synthesis assays. The erythromycin resistance phenotype could not be transferred by cybridization. The mutation appeared to be encoded in the nucleus and inherited as a recessive trait. These two mutants, therefore, represent a new class of erythromycin-resistant mutants in human cells that is distinct from the cytoplasmically inherited mutation in strain ERY2301 described previously.

THYROXINE STIMULATION OF AMINO ACID INCORPORATION INTO MITOCHONDRIAL PROTEIN: DIFFERENCES BETWEEN IN VIVO AND IN VITRO EFFECTS

1973 ◽  
Vol 72 (4) ◽  
pp. 684-696 ◽  
Author(s):  
Amirav Gordon ◽  
Martin I. Surks ◽  
Jack H. Oppenheimer
Keyword(s):  
Protein Synthesis ◽  
Amino Acid ◽  
Mitochondrial Protein ◽  
Leucine Incorporation ◽  
Mitochondrial Protein Synthesis ◽  
Amino Acid Incorporation ◽  
Acid Incorporation ◽  
Stimulation Of

ABSTRACT The in vivo and in vitro stimulation of rat hepatic mitochondrial protein synthesis by thyroxine (T4) was compared. In confirmation of Buchanan & Tapley (1966). T4 added to isolated mitochondria rapidly stimulated [14C] leucine incorporation into mitochondrial protein. The in vitro stimulation was reversed after T4 was removed by incubating the mitochondria with bovine serum albumin (BSA). The decrease in T4 stimulation of protein synthesis appeared proportional to the T4 removed by BSA. Thus, it appears probable that exchangeable T4 controls the in vitro system. In contrast, the increase in mitochondrial protein synthesis which was observed 3 to 4 days after pretreatment of hypothyroid rats with labelled and non-radioactive T4 was not reversed by BSA treatment. Moreover, mitochondrial radioactivity could not be extracted with albumin. The in vivo phenomenon does not, therefore, appear to be related to exchangeable hormone in the mitochondria. Furthermore, the estimated quantity of T4 associated with mitochondria after in vivo stimulation was at least two orders of magnitude less than that required to produce comparable stimulation of mitochondrial protein synthesis in vitro. These findings strongly suggest that in vitro and in vivo stimulation of amino acid incorporation by T4 may be mediated by different biochemical mechanisms.

FK506 affects mitochondrial protein synthesis and oxygen consumption in human cells

2013 ◽  
Vol 29 (6) ◽  
pp. 407-414 ◽  
Author(s):  
María Palacín ◽  
Eliecer Coto ◽  
Laura Llobet ◽  
David Pacheu-Grau ◽  
Julio Montoya ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Oxygen Consumption ◽  
Mitochondrial Protein ◽  
Human Cells ◽  
Mitochondrial Protein Synthesis

scholarly journals The lability of the products of mitochondrial protein synthesis in Saccharomyces cerevisiae. A novel method for protein half-life determination

1978 ◽  
Vol 170 (3) ◽  
pp. 569-576 ◽  
Author(s):  
G Y Bakalkin ◽  
S L Kalnov ◽  
A V Galkin ◽  
A S Zubatov ◽  
V N Luzikov
Keyword(s):  
Protein Synthesis ◽  
Half Life ◽  
Mitochondrial Protein ◽  
Double Labelling ◽  
Mitochondrial Protein Synthesis ◽  
Mitochondrial Translation ◽  
Novel Method ◽  
The Difference ◽  
First Time

A method for the determination of the half-life of mitochondrial translation products in yeast in vivo is proposed. The method uses inhibitors of cytoplasmic and mitochondrial protein synthesis and is based on double-labelling pulse-chase techniques, the second label being used to estimate ‘post-incorporation’ during the ‘chase’. For the first time the difference between post-incroporation and the widely known recycling of the label is considered. These studies show that, in the turnover of mitochondrial translation products, the problem is of post-incorporation into mitochondria (especially from the cell sap) is predominant. The results obtained with this procedure indicate that the half-life of the products of mitochondrial protein synthesis in yeast at the late-exponential phase is about 60 min. The results suggest that mitochondrial transplantation products are subject to proteolysis to acid-soluble forms.

scholarly journals High resolution imaging of nascent mitochondrial protein synthesis in cultured human cells

2020 ◽  
Author(s):  
Matthew Zorkau ◽  
Christin A Albus ◽  
Rolando Berlinguer-Palmini ◽  
Zofia MA Chrzanowska-Lightowlers ◽  
Robert N. Lightowlers
Keyword(s):  
Protein Synthesis ◽  
Outer Membrane ◽  
Mitochondrial Protein ◽  
Human Cells ◽  
Mitochondrial Rna ◽  
Mitochondrial Protein Synthesis ◽  
Inner Mitochondrial Membrane ◽  
Rna Granules ◽  
Cultured Human Cells ◽  
Boundary Membrane

AbstractHuman mitochondria contain their own genome, mtDNA, that is expressed in the mitochondrial matrix. This genome encodes thirteen vital polypeptides that are components of the multi-subunit complexes that couple oxidative phosphorylation (OXPHOS). The inner mitochondrial membrane that houses these complexes comprises the inner boundary membrane that runs parallel to the outer membrane, infoldings that form the cristae membranes, and the cristae junctions that separate the two. It is in these cristae membranes that the OXPHOS complexes have been shown to reside in various species. The majority of the OXPHOS subunits are nuclear-encoded and must therefore be imported from the cytosol through the outer membrane at contact sites with the inner boundary membrane. As the mitochondrially-encoded components are also integral members of these complexes, where does nascent protein synthesis occur? Transcription, mRNA processing, maturation and at least part of the mitoribosome assembly process occur at the nucleoid and the spatially juxtaposed mitochondrial RNA granules, is protein synthesis also performed at the RNA granules close to these entities, or does it occur distal to these sites ? We have adapted a click chemistry based method, coupled with STED nanoscopy to address these questions. We report that in human cells in culture, within the limits of our methodology, the majority of mitochondrial protein synthesis occurs at the cristae membranes and is spatially separated from the sites of RNA processing and maturation.

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