Comparative studies on mitochondrial and cytoplasmic ribosomes of Tetrahymena pyriformis

Chi, Jo-Feng; Suyama, Yoshitaka

doi:10.1016/0022-2836(70)90082-3

Cited by 86 publications

(21 citation statements)

References 32 publications

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“…Different protein compositions of mitochondrial and cytoplasmic ribosomes have been observed in fungi [7], plants [8] and protozoa [9] . Until now differences in the subunit proteins have been shown only with Neurospora [lo]…”

Section: Electrophoretic Patterns Of Ribosomal Proteinsmentioning

confidence: 99%

The mitochondrial ribosome from Locusta migratoria: Dissociation into subunits

Kleinow

Neupert

1971

FEBS Letters

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Section: Electrophoretic Patterns Of Ribosomal Proteinsmentioning

confidence: 99%

The mitochondrial ribosome from Locusta migratoria: Dissociation into subunits

Kleinow

Neupert

1971

FEBS Letters

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“…With regard to RNA in mitochondria in animal cells or plastids in plant cells, many studies have reported on various cells of various plants and animals since the 1960s with biochemical approaches (Knight, 1969;Chi and Suyama, 1970) or by biochemical and morphological approaches (André and Marinozzi, 1965;Swift, 1965;O'Brien and Kalf, 1967a,b;Schatz, 1970;Tandler and Hoppel, 1972). Most of these authors observed mitochondrial ribosomes in the matrix compartment as small particles, 10-15 nm in diameter, by electron microscopic observation, which were extracted with RNase.…”

Section: Discussionmentioning

confidence: 99%

Electron microscopic radioautographic study of RNA synthesis in hepatocyte mitochondria of aging mouse

Nagata

2005

Microsc. Res. Tech.

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In order to study the aging changes of intramitochondrial RNA synthesis in mouse hepatocytes, 10 groups of aging mice, each consisting of three individuals (total 30) from fetal day 19 to postnatal month 24 were injected with 3 H-uridine, an RNA precursor, sacrificed 1 hour later, and the liver tissues processed for electron microscopic radioautography. On EM radioautograms obtained from each animal the number of mitochondria, the number of labeled mitochondria, and the mitochondrial labeling index labeled with 3 H-uridine showing RNA synthesis in each hepatocytes, both mononucleate and binucleate cells, were counted and the averages in respective aging groups were compared. From the results it was demonstrated that the numbers of mitochondria, the numbers of labeled mitochondria, and the labeling indices of intramitochondrial RNA syntheses in both mononucleate and binucleate hepatocytes of mice at various ages increased and decreased according to the age of the animals. INTRODUCTIONIntramitochondrial nucleic acid syntheses, both DNA and RNA, in mammalian and avian cells were first demonstrated morphologically by the present authors by means of electron microscopic radioautography with accurate localization in primary cultured cells of the livers and kidneys of mice and chickens in vitro (Nagata et al., 1967a,b) and then in some other established cell lines such as HeLa cells (Nagata, 1972a-d) or mitochondrial fractions prepared from in vivo cells (Nagata, 1974;Nagata et al., 1975Nagata et al., , 1976. It was later commonly found in various cells and tissues not only in vitro obtained from various organs in vivo (Nagata, 1984; Nagata and Murata, 1977; Nagata et al., 1977a-c), but also in vivo cells of various organs such as the salivary glands (Nagata et al., 2000), the liver (Nagata et al., 1979(Nagata et al., , 1982a Ma and Nagata, 1988;Ma et al., 1994), the pancreas (Nagata, 1992;Nagata et al., 1986), the trachea (Sun et al., 1997), the kidneys (Hanai et al., 1994), the testis (Gao et al., , 1995, the uterus (Yamada and Nagata, 1994a,b), the adrenals (Ito and Nagata, 1996;Liang et al., 1999), the brains , the retina (Gunarso, 1984;Gunarso et al., 1996Gunarso et al., , 1997Kong and Nagata, 1994) of mice, rats, and chickens. The relationship between the intramitochondrial RNA synthesis and cell cycle was formerly studied and it was clarified that the intramitochondrial DNA synthesis was performed without nuclear involvement (Nagata, 1972b). However, the relationship between RNA synthesis and the aging of individual animals has not yet been clarified. This article deals with the relationship between RNA synthesis and aging in hepatocytes of mice in vivo at various ages by means of electron microscopic radioautography as part of a serial studies on special cytochemistry (Nagata, 2001) and radioautographology (Nagata, 2002).

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“…of 95% ethanol. For preparation of a post-ribosomal supernatant [14], purified mitochondria were resuspended in buffer (100 mM KC1, 10 mM MgCI 2, 10 mM Tris-HCl, pH 7.4) and lysed at a final concentration of 2% Triton X-100. After removal of membrane fragments by centrifugation at 10,000 rpm for 10 rain (IEC), the clarified mitochondrial lysate was centrifuged at 42,000 rpm for 90 min in a Ti50 rotor to sediment ribosomes.…”

Section: Methodsmentioning

confidence: 99%

Primary sequence and post‐transcriptional modification pattern of an unusual mitochondrial tRNA^Met from Tetrahymena pyriformis

1995

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We have now isolated and characterized the smallest T. pyriformis mitochondrial tRNA and we show here that it has the primary sequence that we had predicted from the trnM sequence. The transcript also contains a Y-terminal CCA sequence, not encoded in the mtDNA, as well as several modified nucleosides characteristic of known functional tRNAs. Materials and methodsT. pyriformis, amicronucleate strain ST (obtained from Y. Suyama, Department of Biology, University of Pennsylvania), was grown at 28°C with constant shaking in 500 ml NeWs medium [9]. The culture was chilled on ice for 10 15 min, following which cells were collected by centrifugation at 2000 rpm for 5 min, resuspended, and centrifuged at 2000 rpm for 5 min through a layer of ice-cold homogenizing medium (0.35 M sucrose, 10 mM Tris-HC1, pH 7.2, 2 mM EDTA) [10]. Resuspended cells in 50 ml homogenizing medium were disrupted by three passages through a hand emulsifier (nozzle unscrewed 2.5 turns) [11]. Unbroken cells and debris were removed by centrifugation at 3000 rpm (IEC) for 5 min. A mitochondrial pellet was recovered from the resulting supernatant by centrifugation at 8000 rpm for 5 min and washed twice by resuspension in 50 ml homogenizing medium followed by centrifugation (5 min, 8000 rpm). The final mitochondrial pellet was resuspended in 10 ml 0.15 M NaC1, 0.1 M EDTA (pH 9.0) [12] at room temperature. Ten ml of 4% SDS in the same buffer were added and the mitochondrial lysate was then extracted three times with phenol/cresol [13] at room temperature. Nucleic acids were precipitated by addition of 2 vols. of 95% ethanol. For preparation of a post-ribosomal supernatant [14], purified mitochondria were resuspended in buffer (100 mM KC1, 10 mM MgCI 2, 10 mM Tris-HCl, pH 7.4) and lysed at a final concentration of 2% Triton X-100. After removal of membrane fragments by centrifugation at 10,000 rpm for 10 rain (IEC), the clarified mitochondrial lysate was centrifuged at 42,000 rpm for 90 min in a Ti50 rotor to sediment ribosomes. Transfer RNA was isolated from the supernatant by detergent phenol/cresol extraction.Nucleic acid samples were either used directly for 3'-end-labeling or, alternatively, the RNA samples (5 ~tg post-ribosomal supernatant RNA or 20/lg total nucleic acid) were dissolved in 7.5/11 NMF/urea loading buffer [15] containing 0.1% (w/v) xylene cyanol or Bromophenol blue and heated to 65°C for 5 min. After electrophoresis in a thin (0.5 ram) 6% polyacrylamide gel containing 7 M urea, the smallest tRNA was visualized by ethidium bromide staining and eluted [16] in the presence of 20 gtg linear polyacrylamide carrier (prepared as in [17], extracted with phenol, precipitated with ethanol and re-dissolved at 2.5 flg//.tl). The unlabeled tRNA was either re-purified by gel-electrophoresis and then subjected to modified nucleotide analysis [16] or used directly for end-labeling. 3'-End-labeled tRNA [18] was purified by gel-electrophoresis and used for chemical sequence analysis [18]; both 3'-and 5'-endlabeled tRNAs were subjected to enzymatic s...

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Comparative studies on mitochondrial and cytoplasmic ribosomes of Tetrahymena pyriformis

Cited by 86 publications

References 32 publications

The mitochondrial ribosome from Locusta migratoria: Dissociation into subunits

The mitochondrial ribosome from Locusta migratoria: Dissociation into subunits

Electron microscopic radioautographic study of RNA synthesis in hepatocyte mitochondria of aging mouse

Primary sequence and post‐transcriptional modification pattern of an unusual mitochondrial tRNA^Met from Tetrahymena pyriformis

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Comparative studies on mitochondrial and cytoplasmic ribosomes of Tetrahymena pyriformis

Cited by 86 publications

References 32 publications

The mitochondrial ribosome from Locusta migratoria: Dissociation into subunits

The mitochondrial ribosome from Locusta migratoria: Dissociation into subunits

Electron microscopic radioautographic study of RNA synthesis in hepatocyte mitochondria of aging mouse

Primary sequence and post‐transcriptional modification pattern of an unusual mitochondrial tRNAMet from Tetrahymena pyriformis

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Primary sequence and post‐transcriptional modification pattern of an unusual mitochondrial tRNA^Met from Tetrahymena pyriformis