scholarly journals EXPRESSION OF THE MITOCHONDRIAL GENOME IN HELA CELLS

1973 ◽  
Vol 56 (3) ◽  
pp. 819-831 ◽  
Author(s):  
Brian Storrie ◽  
Giuseppe Attardi
Keyword(s):  
Protein Synthesis ◽  
Mitochondrial Genome ◽  
Hela Cells ◽  
Mitochondrial Protein ◽  
Selective Inhibition ◽  
Mitochondrial Protein Synthesis ◽  
Cloning Efficiency ◽  
Cell Growth Inhibition ◽  
Progressive Loss ◽  
Two Generations

The effect of selective inhibition of mitochondrial protein synthesis by chloramphenicol at 40 or 200 µg/ml on the formation of mitochondria in HeLa cells was investigated. HeLa cells, under the conditions used in the present work, grow at a decreasing rate for at least four cell generations in the presence of 40 µg/ml chloramphenicol, and for two generations in the presence of 200 µg/ml chloramphenicol. The progressive cell growth inhibition which begins after 2 days of exposure of the cells to 40 µg/ml chloramphenicol is immediately or gradually reversible, upon removal of the drug, for periods up to at least 8 days of treatment, though there is a progressive loss of cloning efficiency. In cells which have been treated for 6–7 days with 40 or 200 µg/ml of chloramphenicol, mitochondrial protein synthesis occurs at a normal or near-normal rate 1 h after removal of the drug. Mitochondria increase normally in number and show a normal size and amount of cristae in the presence of either concentration of drug. However, in 4–5% of the mitochondrial profiles the cristae appear to be arranged in unusual, circular, looped or whorled configuration.

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.

scholarly journals Mitonuclear Interactions in the Maintenance of Mitochondrial Integrity

Life ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 173
Author(s):  
Panagiotis Karakaidos ◽  
Theodoros Rampias
Keyword(s):  
Mitochondrial Dna ◽  
Protein Synthesis ◽  
Mitochondrial Genome ◽  
Aging Process ◽  
Mitochondrial Protein ◽  
Eukaryotic Cells ◽  
Mitochondrial Protein Synthesis ◽  
Respiratory Chain Complexes ◽  
Chain Complexes ◽  
Insight Into

In eukaryotic cells, mitochondria originated in an α-proteobacterial endosymbiont. Although these organelles harbor their own genome, the large majority of genes, originally encoded in the endosymbiont, were either lost or transferred to the nucleus. As a consequence, mitochondria have become semi-autonomous and most of their processes require the import of nuclear-encoded components to be functional. Therefore, the mitochondrial-specific translation has evolved to be coordinated by mitonuclear interactions to respond to the energetic demands of the cell, acquiring unique and mosaic features. However, mitochondrial-DNA-encoded genes are essential for the assembly of the respiratory chain complexes. Impaired mitochondrial function due to oxidative damage and mutations has been associated with numerous human pathologies, the aging process, and cancer. In this review, we highlight the unique features of mitochondrial protein synthesis and provide a comprehensive insight into the mitonuclear crosstalk and its co-evolution, as well as the vulnerabilities of the animal mitochondrial genome.

MITOCHONDRIAL PROTEIN SYNTHESIS IN HeLa CELLS

1973 ◽  
Vol 74 (Suppl) ◽  
pp. S263-S293 ◽  
Author(s):  
Giuseppe Attardi ◽  
Paolo Costantino ◽  
James England ◽  
Muriel Lederman ◽  
Deanna Ojala ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Hela Cell ◽  
Hela Cells ◽  
Messenger Rna ◽  
Polyacrylamide Gel Electrophoresis ◽  
Cell Mass ◽  
Mitochondrial Protein ◽  
Mitochondrial Protein Synthesis ◽  
Functional Protein ◽  
Strong Constraint

ABSTRACT HeLa cell mitochondrial polysomes, estimated to consist of two to seven 60S monomers, exhibit an unusual resistance to RNase and EDTA, possibly related to the strongly hydrophobic nature of their polypeptide products which makes the nascent chains particularly "sticky". Mitochondria-specific ribosomal and 4S RNA are coded for by mitochondrial DNA (mit-DNA): there is one gene for each ribosomal RNA (rRNA) species and nine genes for 4S RNA on the heavy (H) mit-DNA strand, and three 4S RNA genes on the light (L) strand. The existence of messenger RNA (mRNA) transcribed from mit-DNA is strongly suggested by the occurrence in mitochondria of poly(A) stretches, 60 to 80 residues long, most of which are covalently linked to RNA molecules coded for by mit-DNA. Mitochondrial poly(A) is not a transcription product of mit-DNA. The in vivo and in vitro products of mitochondrial protein synthesis exhibit by polyacrylamide gel electrophoresis a group of not well resolved components in the molecular weight range from 12 000 to 25 000 daltons, and another group, more abundant, in the range from 40 000 to 55 000 daltons. A strong constraint appears to exist in the pattern of amino acid utilization by HeLa cell mitochondria, with a very low level, if any, of incorporation of the charged polar amino acids, and a predominant utilization of the most hydrophobic ones. Block of mitochondrial protein synthesis by chloramphenicol for up to four generations of cell growth has no effect on mitochondrial growth and replication, on the rate of mitochondrial nucleic acid synthesis, and on the formation of a functional protein synthesizing apparatus; however, mitochondrial protein synthesis is required for the formation of a functional cytochrome c oxidase. No significant differences in the rate of mitochondrial protein synthesis per unit of cell mass, nor in the size distribution of the protein products, were found in HeLa cells in different phases of the cell cycle.

scholarly journals 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.

Sign in / Sign up

Export Citation Format

Share Document