Incorporation of Labeled Amino Acids into the Protein of Muscle and Liver Mitochondria

McLean, John H.; Cohn, George L.; Brandt, Ira K.; Simpson, Melvin V.

doi:10.1016/s0021-9258(18)64722-2

Cited by 211 publications

(15 citation statements)

References 23 publications

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“…Nuclei (1) and mitochondria (55,61) possess recognized mechanisms for production of proteins . When expressed as grain concentration per unit area (Table I), the 4 min values for nuclei and mitochondria are below the average for liver, in accord with the lower incorporation of labeled amino acids into nuclei and mitochondria found when these components were isolated after labeling (14,36,54) .…”

Section: Discussionmentioning

confidence: 65%

Electron Microscopic Radioautographic Detection of Sites of Protein Synthesis and Migration in Liver

Ashley

Peters

1969

The Journal of Cell Biology

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The sites of synthesis of proteins and their subsequent migration in rat liver have been studied during a 75 min period after labeling of liver-slice proteins by exposure to leucine-H3 for 2 min. Incorporation of the label into protein began after 1 min and was maximal by 4 min. Electron microscopic radioautography showed that synthesis of proteins in hepatocytes occurs mainly on ribosomes, particularly those in rough endoplasmic reticulum and, to some extent, in nuclei and mitochondria. Most of the newly formed proteins leave the endoplasmic reticulum in the course of 40 min, and concurrently labeled proteins appear in Golgi bodies, smooth membranes, microbodies, and lysosomes. A likely pathway for the secretion of some or all plasma proteins is from typical rough endoplasmic reticulum to a zone of reticulum which is partially coated with ribosomes, to the Golgi apparatus, and thence to the cell periphery. The formation of protein by reticuloendothelial cells was measured and found to be about 5% of the total protein formed by the liver.

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Section: Discussionmentioning

confidence: 65%

Electron Microscopic Radioautographic Detection of Sites of Protein Synthesis and Migration in Liver

Ashley

Peters

1969

The Journal of Cell Biology

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“…M . Simpson's group (108) found this held for liver mitochondria . Also, a correlation had been made (19,109) between the occurrence of membrane-bound ribosomes and the secretory status of the cells that contain them.…”

Section: Structure and Function Of The Ribosomementioning

confidence: 93%

Ribosomes and protein synthesis.

Siekevitz¹,

Zamecnik²

1981

The Journal of Cell Biology

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Let us start at the very beginning. Between 1897 and 1899, G. Gamier, in France, published elegant microscope studies describing a basophilic component ofthe cytoplasm of glandular cells (1) . Because of what he thought its role might be in the elaboration and transformation of secretory products, he gave a Greek name to these concepts-ergastoplasm (work plasm) . Gamier's research was extended by others-particularly A. Prenant, R. R. Bensley, and A. Matthews-to include other cell types, so that by the early part of this century ergastoplasm came to be a generally accepted term for a specific basophilic area of the cytoplasm . These early studies are extensively reviewed by F. Haguenau (1) . The next major advance was to show that basophilia was due to RNA: in 1933, J. Brachet used RNase (2) ; in 1939, T. Caspersson used ultraviolet spectrophotometry (3); in 1943, J. N. Davidson and C. Waymouth used chemical methods (4) . The high correlation which was shown between the amount ofRNA in various cells and the postulated protein-synthesizing capacity of those cells led Caspersson in 1941 (5) and Brachet in 1942 (6) to proclaim the importance of RNA in the process of protein synthesis . As can be imagined, this conjecture spurred many scientists in the next decade to try to answerthree questions. In what form was this cytoplasmic RNA? Did it really have a role in protein synthesis? Ifso, what was the role? Various methods were used: extraction and chemical procedures; extraction and physicochemical procedures, such as ultracentrifugation; and, because electron microscopy was becoming more and more refined, visualization . We now know that the RNA is in the form of ribosomes, and that the proteins of the ribosomes are involved in the many individual steps of protein synthesis; however, the function of ribosomal RNA is still elusive .The intensity of the research in the 1940s is caught very well in Haguenau's chapter on the visualization aspect (1) and in Magasanik's 1955 monograph ( 7) on the extraction and chemical properties of what were then called "pentose nucleoprotein." Confusion abounded, in good part due to the terminologies developed for the different techniques, such as Gamier's ergastoplasm, K. Porter's "endoplasmic reticulum" (8), A. Claude's "microsome" fraction (9), G. Palade's "small particulate component" (10), and the "nucleoprotein" preparations or particles discovered by various workers . The last are re-

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“…Generally, however, the mitochondrial incorporation system shows a requirement for oxidizable substrate, inorganic phosphate, Mg2+ ions and certain adenine nucleotides (Beattie et al 1967), is inhibited almost completely by chloramphenicol at concentrations as low as 50,ug./ml. (Kroon, 1965) and is insensitive to concentrations of ribonuclease far above those that would completely abolish microsomal incorporation (McLean, Cohn, Brandt & Simpson, 1958).…”

Section: Biochem J (1967) 105 44cmentioning

confidence: 99%

Short Communications

1967

Biochemical Journal

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The biochemical significance of 'lethal synthesis' has been repeatedly emphasized by Peters (1963) and this has undoubtedly provided the rationale for the synthesis of a wide range of fluorinated analogues in the steroid (reviewed by Taylor & Kent, 1965), carboxylic acid (Pattison, 1959) and heterocyclic (e.g. 5-fluorouracil; Hartman & Heidelberger, 1961) fields in which hydrogen has been replaced by fluorine. Comparative physicochemical studies with 6deoxy-6-fluoro-D-galactose (Kent, Morris & Taylor, 1960) and X-ray crystallographic studies with 2-deoxy-2-fluoroerythritol and erythritol (Bekoe & Powell, 1959) show that only minor differences in physical and chemical properties result when a hydroxyl group is replaced by fluorine in these compounds. These results, together with the similarity in size and electronegativity between the hydroxyl group and fluorine, suggest the possibility that suitably substituted fluoro sugars and related compounds might provide new inhibitors of carbohydrate metabolism. Biochemical studies already reported with 2-deoxy-2-fluoroerythritol (Smith, Anderson, Keppie, Kent & Timmis, 1965), which acts as a growth inhibitor of Brucella abortus, and 2-deoxy-2-fluoroglycerol (O'Brien & Peters, 1958) support this suggestion. It is only recently, however, that fluoropentoses (Wright & Taylor, 1967) and fluorohexoses (Buck, Foster, Hems & Weber, 1966) with fluorine in other than the anomeric (reviewed by Michael & Klemer, 1961) or terminal positions (Taylor & Kent, 1958) of monosaccharides have become available.We now report some preliminary biochemical results with 3FG* (Buck et al. 1966). The structure of this compound has been established (Foster, Hems & Weber, 1967) by degradation to the known 3-deoxy-3-fluoro-D-xylose (Wright & Taylor, 1967).Materials and methods. 3FG was a gift from Professor A. B. Foster and Mr R. Hems. C02 evolution, determined by the method of Johnson (Umbreit, Burris & Stauffer, 1964), and oxygen uptake were measured in a Warburg respirometer. The extent of respiration was determined by continuing the experiments until

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Incorporation of Labeled Amino Acids into the Protein of Muscle and Liver Mitochondria

Cited by 211 publications

References 23 publications

Electron Microscopic Radioautographic Detection of Sites of Protein Synthesis and Migration in Liver

Electron Microscopic Radioautographic Detection of Sites of Protein Synthesis and Migration in Liver

Ribosomes and protein synthesis.

Short Communications

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