Action of streptomycin on the growth of Streptomyces griseus

1974 ◽  
Vol 20 (11) ◽  
pp. 1591-1597 ◽  
Author(s):  
R. Cella ◽  
L. C. Vining
Keyword(s):  
Protein Synthesis ◽  
Natural Population ◽  
Streptomyces Griseus ◽  
Drastic Reduction ◽  
Cell Extracts ◽  
Polyuridylic Acid ◽  
Directed Polymerization ◽  
Selection Of

A streptomycin-producing culture of Streptomyces griseus was sensitive to streptomycin, but inhibition was temporary, and cultures supplemented with the antibiotic up to 100 μg/ml grew after a lag. Streptomycin tolerance developed, not by inactivation of the antibiotic but by selection of resistant variants in the natural population. Addition of streptomycin to growing cultures caused a drastic reduction in protein synthesis and an accumulation of "stuck" (70 S) ribosomes within the mycelium. Although the effect on protein synthesis could not be confirmed in vitro because cell extracts from S. griseus contained an inhibitor of polyuridylic-acid-directed polymerization of L-phenylalanine, it is concluded that streptomycin prevents the growth of this organism by a mechanism similar to that observed with other bacteria and that the tolerance of producing cultures cannot be attributed to the presence of streptomycin-resistant ribosomes.

Plasminogen Activator (PA) Activity In Metastatic Cells: An Amidolytic Approach

1981 ◽  
Author(s):  
D Coen ◽  
A Bini ◽  
G Balconi ◽  
F Delaini ◽  
L Mussoni ◽  
...  
Keyword(s):  
Primary Tumor ◽  
Fibrinolytic Activity ◽  
Tumor Tissue ◽  
Cultured Cells ◽  
Cell Extracts ◽  
Mechanical Disruption ◽  
Metastatic Cells ◽  
Triton X ◽  
Selection Of

It has been proposed that fibrinolytic activity can play an important role in the process of metastasis formation. Nevertheless, it is not yet clear in which phase of the tumor growth and dissemination this activity is involved. We measured the fibrinolytic activity of cells from primary tumor and metastatic nodules of 3LL, an i.m. implanted murine tumor which selectively metastasizes to the lungs. Tumor cells have been studied both immediately after mechanical disruption of tumor tissue and after in vitro culturing to confluence. Their P.A. activity was tested by an amidolytic assay in which cells were incubated with purified plasminogen (3CU/ml) and 4mM S-2251 (Kabi Diagnostica, Stockholm, Sweden), a plasmin specific chromogenic substrate. After 3 hour incubation at 37°C, the reaction was stopped with acetic acid and absorbance read at 405 nm.Cells from the primary tumor and metastatic nodules showed a similar fibrinolytic activity, which was in both cases in- increased 3 to 4 fold in cell extracts obtained after preincubation with TRITON X-100. A dose-response curve plotted with increasing urokinase concentrations showed a parallel course. This data suggests that, in the 3LL model, PA activity is not one of the properties characterizing the selection of metastatic cells.On the other hand,cultured cells presented consistently higher levels of PA than their native counterparts, suggesting that adhesion of cells in culture may stimulate PA production or, alternatively, that cultured cells are a selected population in comparison to the overall number of native cells.

Activation of Protein Synthesis in Aging Potato Tuber Slices

1971 ◽  
Vol 26 (10) ◽  
pp. 1064-1067 ◽  
Author(s):  
Günter Kahl
Keyword(s):  
Protein Synthesis ◽  
Potato Tuber ◽  
Actinomycin D ◽  
Leucine Incorporation ◽  
Amino Acid Incorporation ◽  
Acid Incorporation ◽  
Fresh Potato ◽  
Polyuridylic Acid ◽  
Storage Organs

Whereas ribosome preparations of freshly sliced potato disks do not show appreciable activity in an in-vitro amino acid incorporation system, aging of the tissue leads to a greatly enhanced incorporation activity which reaches its maximum 24 hours after slicing. If ribosomes from freshly excised disks are provided with polyuridylic acid, their activity in the incorporation of phenylalanine is increased about 8 fold.Moreover, an RNA-fraction can be dissociated by EDTA from ribosomes of aged potato tuber slices, which sediments at 15 —18S, has a base composition different from that of 16S — rRNA, 5S-and 4S —RNA, and is not present on ribosomes of fresh slices. Its appearance is inhibited by actinomycin D and therefore most probably dependent on transcription. This compound, purified from sucrose gradients, enhances in vitro leucine incorporation into peptide material by ribosomes of fresh potato slices.The possibility is discussed that this fraction-among other factors-is responsible for the enhanced protein synthesis after slicing plant storage organs, and is indicative of a general derepression phenomenon in these tissues.

scholarly journals Effect of mitochondrial protein synthesis inhibitors on erythroid differentiation of mouse erythroleukemia (Friend) cells.

1988 ◽  
Vol 8 (8) ◽  
pp. 3311-3315 ◽  
Author(s):  
T Kaneko ◽  
T Watanabe ◽  
M Oishi
Keyword(s):  
Protein Synthesis ◽  
Early Stage ◽  
Mitochondrial Protein ◽  
Specific Inhibitor ◽  
Erythroid Differentiation ◽  
Mitochondrial Protein Synthesis ◽  
Cell Extracts ◽  
Factor Ii ◽  
Mouse Erythroleukemia

When mouse erythroleukemia (MEL) cells were incubated in the presence of chloramphenicol (a specific inhibitor for mitochondrial protein synthesis) during the early stage of in vitro erythroid differentiation, the number of induced erythroid cells was greatly reduced. By use of cell fusion between two genetically marked MEL cells, this finding was further investigated. We found that the drug, along with other agents which inhibit mitochondrial protein synthesis, blocked the induction and turnover of the DMSO-inducible intracellular-erythroid-inducing activity (differentiation-inducing factor II) in a manner similar to that of cycloheximide, an inhibitor for nuclear protein synthesis. The inhibitory effect was confirmed by directly assaying differentiation-inducing factor II in the cell extracts. These results strongly suggest that mitochondrial protein synthesis is closely associated with in vitro erythroid differentiation of MEL cells.

scholarly journals Magnetic Tracking of Protein Synthesis in Microfluidic Environments—Challenges and Perspectives

Nanomaterials ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 585 ◽  
Author(s):  
Wegener ◽  
Ennen ◽  
Walhorn ◽  
Anselmetti ◽  
Hütten ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Cell Biology ◽  
Ex Vivo ◽  
Microfluidic Devices ◽  
Cellular Protein ◽  
Fine Tuning ◽  
Superparamagnetic Particles ◽  
Magnetic Tracking ◽  
Selection Of

A novel technique to study protein synthesis is proposed that uses magnetic nanoparticles in combination with microfluidic devices to achieve new insights into translational regulation. Cellular protein synthesis is an energy-demanding process which is tightly controlled and is dependent on environmental and developmental requirements. Processivity and regulation of protein synthesis as part of the posttranslational nano-machinery has now moved back into the focus of cell biology, since it became apparent that multiple mechanisms are in place for fine-tuning of translation and conditional selection of transcripts. Recent methodological developments, such as ribosome foot printing, propel current research. Here we propose a strategy to open up a new field of labelling, separation, and analysis of specific polysomes using superparamagnetic particles following pharmacological arrest of translation during cell lysis and subsequent analysis. Translation occurs in polysomes, which are assemblies of specific transcripts, associated ribosomes, nascent polypeptides, and other factors. This supramolecular structure allows for unique approaches to selection of polysomes by targeting the specific transcript, ribosomes, or nascent polypeptides. Once labeled with functionalized superparamagnetic particles, such assemblies can be separated in microfluidic devices or magnetic ratchets and quantified. Insights into the dynamics of translation is obtained through quantifying large numbers of ribosomes along different locations of the polysome. Thus, an entire new concept for in vitro, ex vivo, and eventually single cell analysis will be realized and will allow for magnetic tracking of protein synthesis.

Effect of mitochondrial protein synthesis inhibitors on erythroid differentiation of mouse erythroleukemia (Friend) cells

1988 ◽  
Vol 8 (8) ◽  
pp. 3311-3315
Author(s):  
T Kaneko ◽  
T Watanabe ◽  
M Oishi
Keyword(s):  
Protein Synthesis ◽  
Early Stage ◽  
Mitochondrial Protein ◽  
Specific Inhibitor ◽  
Erythroid Differentiation ◽  
Mitochondrial Protein Synthesis ◽  
Cell Extracts ◽  
Factor Ii ◽  
Mouse Erythroleukemia

When mouse erythroleukemia (MEL) cells were incubated in the presence of chloramphenicol (a specific inhibitor for mitochondrial protein synthesis) during the early stage of in vitro erythroid differentiation, the number of induced erythroid cells was greatly reduced. By use of cell fusion between two genetically marked MEL cells, this finding was further investigated. We found that the drug, along with other agents which inhibit mitochondrial protein synthesis, blocked the induction and turnover of the DMSO-inducible intracellular-erythroid-inducing activity (differentiation-inducing factor II) in a manner similar to that of cycloheximide, an inhibitor for nuclear protein synthesis. The inhibitory effect was confirmed by directly assaying differentiation-inducing factor II in the cell extracts. These results strongly suggest that mitochondrial protein synthesis is closely associated with in vitro erythroid differentiation of MEL cells.

scholarly journals A new in vitro assay measuring direct interaction of nonsense suppressors with the eukaryotic protein synthesis machinery

2018 ◽  
Author(s):  
Martin Y. Ng ◽  
Haibo Zhang ◽  
Amy Weil ◽  
Vijay Singh ◽  
Ryan Jamiolkowski ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Single Molecule ◽  
Direct Interaction ◽  
Vitro Assay ◽  
Premature Termination Codons ◽  
Protein Synthesis Machinery ◽  
Nonsense Suppressor ◽  
Nonsense Suppressors ◽  
Selection Of

ABSTRACTNonsense suppressors (NonSups) induce “readthrough”, i.e., the selection of near cognate tRNAs at premature termination codons and insertion of the corresponding amino acid into nascent polypeptide. Prior readthrough measurements utilized contexts in which NonSups can promote readthrough directly, by binding to one or more of the components of the protein synthesis machinery, or indirectly, by several other mechanisms. Here we utilize a new, highly-purified in vitro assay to measure exclusively direct nonsense suppressor-induced readthrough. Of 16 NonSups tested, 12 display direct readthrough, with results suggesting that such NonSups act by at least two different mechanisms. In preliminary work we demonstrate the potential of single molecule fluorescence energy transfer measurements to elucidate mechanisms of NonSup-induced direct readthrough, which will aid efforts to identify NonSups having improved clinical efficacy.Table of Contents artwork

Protein synthesis by cell-free extracts of Proteus vulgaris

1971 ◽  
Vol 17 (12) ◽  
pp. 1545-1551
Author(s):  
K. L. Backler ◽  
W. E. Inniss
Keyword(s):  
Protein Synthesis ◽  
Ribonucleic Acid ◽  
Supernatant Fraction ◽  
Proteus Vulgaris ◽  
Guanosine Triphosphate ◽  
Cell Extracts ◽  
Polyuridylic Acid ◽  
A Cell ◽  
Directed System ◽  
Low Activity

A cell-free protein-synthesizing system from Proteus vulgaris was developed and characterized. Initially, a very low activity was found to occur; it was shown to be due to a deficiency in the endogenous transfer ribonucleic acid (tRNA) content of the cell extracts. When tRNA was added to the polyuridylic acid (poly U) directed system, incorporation of 14C-phenylalanine into polypeptide readily occurred. This incorporation was dependent on ribosomes and supernatant fraction and the optimum concentrations of the various components of the system were found to be as follows: 120 μg/ml tRNA, 30 mM magnesium, 0.5 mM spermidine, 60 mM potassium, 50 mM adenosine triphosphate (ATP), 5 mM guanosine triphosphate (GTP), 0.03 mM cytosine triphosphate (CTP) and uridine triphosphate (UTP), 5 mM phosphoenolpyruvate (PEP), 50 μg/ml poly U, and 30 mM 2-mercaptoethanol.

Proteinsynthese mit Zellextrakten von Micrococcus radiodurans/ Protein Synthesis with Cell Extracts of Micrococcus radiodurans

1978 ◽  
Vol 33 (11-12) ◽  
pp. 948-954
Author(s):  
Annette Widmann ◽  
Roland Süssmuth
Keyword(s):  
Protein Synthesis ◽  
Optimal Conditions ◽  
Free System ◽  
Cell Free System ◽  
E Coli ◽  
Cell Extracts ◽  
Polyuridylic Acid ◽  
A Cell ◽  
Ribosomal Activity ◽  
Cell Free Protein Synthesis

Abstract Pure active ribosomes of cells of Micrococcus radiodurans could be obtained when cultivated in trypton, glucose and nutrient broth by adding natrium citrate. The optimal conditions for a cell-free protein synthesis were investigated at the (polyuridylic acid) dependent polyphenylalanine synthesis. When exchanging ribosomes and S100-fractions with the corresponding fractions of E. coli, we found that the enzyme fractions of M. radiodurans extremely inhibit the ribosomal activity. The incorporation rates in the cell-free system of M. radiodurans yield, at com parable conditions, in relation to E. coli under 10%.

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