Synthesis of nuclear and chromosomal proteins on light polyribosomes during cleavage in the sea urchin embryo

Kedes, Laurence H.; Gross, Paul R.; Cognetti, Goffredo; Hunter, Anne L.

doi:10.1016/0022-2836(69)90109-0

Cited by 121 publications

(20 citation statements)

References 18 publications

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“…In a series of elegant studies, Robbins and coworkers have identified a class of small cytoplasmic polysomes in HeLa cells which is present only during histone synthesis and which incorporates labeled amino acids into a product resembling histones (1)(2)(3). Similar results have been obtained by others (4,5), and it has been inferred by these investigators that histones are synthesized in the cytoplasm and then transferred to the nucleus. On the other hand, several groups of workers have demonstrated that isolated thymus nuclei can incorporate labeled amino acids into histones (6)(7)(8)(9); these investigators have concluded that histone synthesis occurs within the cell nucleus.…”

Section: Introductionmentioning

confidence: 55%

“…Thus, Zetterberg has concluded from cytophotometric and radioautographic studies that 65% of the nuclear mass of growing mouse fibroblasts is synthesized in the cytoplasm (10), and Byers et al have shown by nuclear transplantation experiments that, in amoebae, several classes of nuclear proteins are of cytoplasmic origin (11). Transfer of newly synthesized, labeled proteins from the cytoplasm into the nucleus has also been demonstrated in HeLa cells (12) and in sea urchin embryos (5).…”

Section: Introductionmentioning

confidence: 99%

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Studies on the Site of Synthesis of Several Soluble Enzymes of the Cell Nucleus

Kuehl

Sumsion

1971

The Journal of Cell Biology

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A B S T R A C TRats were given radioactive L-leucinc intravcnously. At various timcs after injcction, the livers were removed and separated into nuclear and cytoplasmic fractions by a nonaqueous technique. Glyccraldehydc-3-phosphate dehydrogenase, aldolase, and lactic dehydrogenase were isolated from each cell fraction by antibody precipitation followed by gel clectrophorcsis, and the spccific radioactivities of the isolated enzymes were determined. In all three cases, the onset of labeling and the rate of incorporation were thc same for the nuclear enzyme as for the corresponding enzyme from the cytoplasm. If wc assume that equilibration of the enzymes between the cytoplasmic and nuclear pools occurs slowly rclativc to the labeling times employed, we may conclude that the labeled nuclcar enzymes either were synthesized in the nucleus or moved into the nucleus from a cytoplasmic site of synthesis without first passing into the cytoplasmic pool of enzyme. Treatment with puromycin, an antibiotic which depresses incorporation into cytoplasmic proteins to a greater extent than into nuclear proteins, led to a situation in which the specific activities of the nuclear enzymes were several times as high as those of the corresponding cytoplasmic enzymes following a short pcriod of incorporation. Thcse data substantiate the assumption that equilibration between the cytoplasmic and nuclear enzyme pools occurs slowly and provide further evidence that the labeled nuclear enzymes do not arise from the cytoplasmic enzyme pool.

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Section: Introductionmentioning

confidence: 55%

Section: Introductionmentioning

confidence: 99%

Studies on the Site of Synthesis of Several Soluble Enzymes of the Cell Nucleus

Kuehl

Sumsion

1971

The Journal of Cell Biology

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“…Histone synthesis by n-polysomes is coupled to DNA replication: inhibition of DNA synthesis led to dissociation of the histone-making polyribosomes, the effect being also observed in HeLa cells [ 1,2,5,1 l] and sea urchin embryos [3,4]. However, in contrast to loach embryos, in sea urchin embryos and other kinds of animal cells, histone polyribosomes have been repeatedly reported to belong to the free polyribosome class [6-81.…”

Section: Discussionmentioning

confidence: 99%

Nucleus‐associated polyribosomes are engaged in the replication‐ and transcription‐dependent histone synthesis in early fish embryos

Strelkov¹,

Chiaureli²,

Kafiani³

1983

FEBS Letters

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“…After SDGC and fractionation, 100 pg of BSA (bovine serum albumin) in 0.5 ml of distilled water and then an equal volume of 15% cold TCA containing 0.5% casamino acids were added to each fraction. The fractions were then heated at 80°C for 30 min (10). The resulting precipitates of each fraction were collected on glass fiber filters (Whatman, GF/C) and washed.…”

Section: N Hirama and Y Man0mentioning

confidence: 99%

Polysomes of the Sea Urchin Embryo: Nature of So-Called "Cyclic Amino Acid Incorporation" and Conditions to Prepare Cell-Free Systems for Protein Synthesis

Hirama¹,

Mano²

1976

Dev Growth Differ

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Cyclic formation of active polysomes in a cell-free system, as reported previously, could not be demonstrated under the conditions reported. However, cyclic fluctuation was observed in incorporation of amino acids into the hot TCA-insoluble fraction. Failure to demonstrate polysome formation seemed to be due to the. lack of GTP and to the necessity to protect SH groups during preparation of the system and its assay. Addition of exogenous GTP and ME effectively restored polysomal activity in the cell-free system. The previously reported cyclic incorporation of amino acids into the hot TCA-insoluble fraction in cell-free systems in the absence of these reagents might be due to cyclic variation in some partial reactions or some phenomenon other than protein synthesis.Cell-free systems for protein synthesis have been well developed and have provided a good deal of useful information on protein synthesis. Using sea urchin embryos, a cell-free system was studied in this laboratory (12,13,14). From these experiments, it was reported that in a cell-free system protein synthesis and formation of active polysomes were observed in parallel. However, it was later shown that the conditions used for preparation of the cell-free system at that time were not suitable for experiments on protein synthesis (4), since, integrated polysomes could not be extracted successfully under those conditions. Moreover, there is a report indicating that cell-free protein synthesis was not observed in sea urchin embryos (1 8). Thus, it was necessary to develop a cell-free system actively engaging in protein synthesis and to study such a system again to investigate the cyclic variation in protein synthesis.The present paper reports that it was found impossible to prepare a cell-free system capable of demonstrating cyclic protein synthesis, even under improved conditions which were effective for preparing a cell-free system that could carry out protein synthesis to some extent. MATERIALS AND METHODSMature eggs of the sea urchin, Anthocidaris crassispina, were used. The methods used for collection of eggs, fertilization and culture were as described previously (4,5, 12).Fertilized eggs were collected 5 min after fertilization or at the blastula stage. The collected embryos were washed once with CMF-SW (Ca2+-, Mg2'-free artificial sea water, 6), and homogenized in 4 vol. of TKMbuffer (0.05 M Tris, pH 7.5, 0.005 M MgClz, 0.32 M KCl and 0.5 mM EDTA-2K) using a Dounce homogenizer (4). In this case, cycloheximide, ME (2-mercaptoethanol) and Nonidet P-40 were not added to the system.

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Synthesis of nuclear and chromosomal proteins on light polyribosomes during cleavage in the sea urchin embryo

Cited by 121 publications

References 18 publications

Studies on the Site of Synthesis of Several Soluble Enzymes of the Cell Nucleus

Studies on the Site of Synthesis of Several Soluble Enzymes of the Cell Nucleus

Nucleus‐associated polyribosomes are engaged in the replication‐ and transcription‐dependent histone synthesis in early fish embryos

Polysomes of the Sea Urchin Embryo: Nature of So-Called "Cyclic Amino Acid Incorporation" and Conditions to Prepare Cell-Free Systems for Protein Synthesis

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