Suppressors suaC 109 and suaA 101 of Aspergillus nidulans alter the ribosomal phenotype in vitro

1987 ◽  
Vol 7 (12) ◽  
pp. 941-948 ◽  
Author(s):  
A. Zamir ◽  
S. S. Martinelli
Keyword(s):  
Protein Synthesis ◽  
Amino Acid ◽  
Aspergillus Nidulans ◽  
Ribosomal Proteins ◽  
Amino Acid Incorporation ◽  
Free System ◽  
Cell Free System ◽  
Translation Factors ◽  
Acid Incorporation

A new homologous, cell-free system for protein synthesis has been devised for use with ribosomes and elongation factors from Aspergillus nidulans. Ribosome preparations from strains with either the suaAlO1 or suaCl09 mutations have a higher misreading ratio (non-cognate:cognate amino acid incorporation) in the presence of hygromycin than controls. They can be classed as fidelity mutants. These results also prove that the mutations must be in genes coding for ribosomal proteins or enzymes which modify ribosomal proteins post-translationally. Alternatively, the genes could code for translation factors.

In vitro protein synthesis directed by R17 viral ribonucleic acid. II. On the fate of mRNA in the cell-free system

1969 ◽  
Vol 47 (12) ◽  
pp. 1179-1186 ◽  
Author(s):  
Satomi J. Igarashi
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Amino Acid Incorporation ◽  
Free System ◽  
Cell Free System ◽  
E Coli ◽  
Acid Incorporation ◽  
Binding Factor ◽  
Vitro Protein

In the crude E. coli B cell-free system, mRNA was hydrolyzed by contaminating nuclease activities before significant polymerization of amino acids took place. Ribosomes appeared to be one of the sources of nuclease. A modified high-salt washing procedure was developed to remove nuclease from ribosomes. RNase-free ribosomes thus obtained appeared to be inactive in poly-U-directed phenylalanine incorporation, unless poly-U binding factor was added to the system. R17 RNA could not direct amino acid incorporation in the presence of RNase-free ribosomes because binding of intact R17 RNA to ribosomes did not take place even in the presence of poly-U binding factor.

scholarly journals Regulation of polyribosome formation and protein synthesis in the uterus. Effect of ovariectomy and administration of oestradiol-17β on the amino acid-incorporation activity in vitro and the cytoplasmic concentration in vivo of polyribosomal preparation

1967 ◽  
Vol 105 (3) ◽  
pp. 1101-1109 ◽  
Author(s):  
Ching-Sung Teng ◽  
Terrell H. Hamilton
Keyword(s):  
Protein Synthesis ◽  
Amino Acid ◽  
Hormonal Regulation ◽  
Ovariectomized Rats ◽  
Cytoplasmic Protein ◽  
Amino Acid Incorporation ◽  
Free System ◽  
Acid Incorporation

1. The hormonal regulation of cytoplasmic protein synthesis in the uterus is described. Polyribosomal preparation from uteri of normal or ovariectomized rats was isolated by procedure 3 and assayed for [14C]leucine-incorporation activity in the cell-free system, as described by Teng & Hamilton (1967). 2. Ovariectomy of normal animals caused, 3 weeks after surgery, a 50–60% increase in the amino acid-incorporation activity in vitro of uterine polyribosomal preparation, but a 90–95% decrease in the cytoplasmic concentration in vivo of the preparation. 3. Administration of 10μg. of oestradiol-17β to ovariectomized rats at zero time caused, 10–12hr. later, a 100% stimulation in amino acid-incorporation activity in vitro of the uterine polyribosomal preparation. From 12hr. to 36hr. after hormone administration, the activity in vitro of the preparation decreased. If a second dose of hormone was administered at 36hr., the activity in vitro of the preparation continued to decrease, and approached at 48hr. and 72hr. the lower activity observed for the preparation from normal animals. The cytoplasmic concentration of polyribosomal preparation increased by 600–700% under these experimental conditions. If a second dose of oestradiol-17β was not administered at 36hr., the initially elevated cytoplasmic concentration of the preparation decreased by 50% from 36hr. to 72hr., and the activity in vitro of the preparation was not fully depressed to the ‘normal’ value. 4. Pretreatment of ovariectomized animals with actinomycin D or cycloheximide abolished 80–90% of the stimulatory effects of hormone treatment on the amino acid-incorporation activity in vitro and cytoplasmic concentration in vivo of uterine polyribosomal preparation. 5. Two major conclusions are drawn from the results reported: that during early oestrogen action new polyribosomes having amino acid-incorporation properties different from those of the old ones appear and accumulate in the cytoplasm of the uterus; and that the regulation of cytoplasmic protein synthesis in the organ by oestrogen is of an indirect nature, with dual effects of the hormone on genetic transcription resulting in turn in a regulation of the rate and amount of genetic translation.

scholarly journals Studies on the inhibition of protein synthesis by selenodiglutathione

1979 ◽  
Vol 180 (1) ◽  
pp. 213-218 ◽  
Author(s):  
L N Vernie ◽  
J G Collard ◽  
A P Eker ◽  
A de Wildt ◽  
I T Wilders
Keyword(s):  
Protein Synthesis ◽  
Amino Acid ◽  
Elongation Factor ◽  
Amino Acid Incorporation ◽  
Free System ◽  
Cell Free System ◽  
E Coli ◽  
Acid Incorporation ◽  
F Cells ◽  
A Cell

Amino acid incorporation in a cell-free system derived from rat liver has previously been found to be inhibited by GSSeSG (selenodiglutathione). In the present experiments the effect of GSSeSG on protein synthesis in 3T3-f cells, on growth and protein synthesis in Escherichia coli, and on amino acid incorporation in a cell-free system derived from E. coli, was studied. GSSeSG inhibits the incorporation of [3H]leucine into protein by 3T3-f cells. This inhibition cannot be reversed by removing GSSeSG and is correlated with the uptake of GSSeSG. Sodium selenite (Na2SeO3) and oxidized glutathione had no inhibitory effect in this system. [3H]Uridine or [3H]thymidine incorporation into RNA or DNA was not inhibited, indicating that the primary action of GSSeSG was on protein synthesis. GSSeSG did not influence the growth of E. coli in a synthetic medium, although enhanced amino acid incorporation was observed. In the cell-free system derived from E. coli, amino acid incorporation was not changed by GSSeSG, indicating that elongation factor G, in contrast to elongation factor 2 of mammalian cell systems, is not blocked by GSSeSG.

Effect of Cycloheximide on In Vitro and In Vivo Protein Synthesis by Certain Tissues of Rats and Pigeons with Special Reference to Muscle

1973 ◽  
Vol 51 (12) ◽  
pp. 933-941 ◽  
Author(s):  
Njanoor Narayanan ◽  
Jacob Eapen
Keyword(s):  
Amino Acids ◽  
Body Weight ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Amino Acid Incorporation ◽  
Contrast Administration ◽  
Acid Incorporation ◽  
Tissue Homogenates

The effect of cycloheximide in vitro and in vivo on the incorporation of labelled amino acids into protein by muscles, liver, kidneys, and brain of rats and pigeons was studied. In vitro incorporation of amino acids into protein by muscle microsomes, myofibrils, and myofibrillar ribosomes was not affected by cycloheximide. In contrast, administration of the antibiotic into intact animals at a concentration of 1 mg/kg body weight resulted in considerable inhibition of amino acid incorporation into protein by muscles, liver, kidneys, and brain. This inhibition was observed in all the subcellular fractions of these tissues during a period of 10–40 min after the administration of the precursor. Tissue homogenates derived from in vivo cycloheximide-treated animals did not show significant alteration in in vitro amino acid incorporation with the exception of brain, which showed a small but significant enhancement.

scholarly journals Action of growth hormone in vitro on the net uptake and incorporation into protein of amino acids in muscle from intact rabbits given protein-deficient diets

1976 ◽  
Vol 35 (1) ◽  
pp. 1-10 ◽  
Author(s):  
M. R. Turner ◽  
P. J. Reeds ◽  
K. A. Munday
Keyword(s):  
Amino Acids ◽  
Growth Hormone ◽  
Protein Synthesis ◽  
Amino Acid ◽  
De Novo ◽  
Amino Acid Uptake ◽  
Acid Uptake ◽  
Amino Acid Incorporation ◽  
Acid Incorporation

1. Net amino acid uptake, and incorporation into protein have been measured in vitro in the presence and absence of porcine growth hormone (GH) in muscle from intact rabbits fed for 5 d on low-protein (LP), protein-free (PF) or control diets.2. In muscle from control and LP animals GH had no effect on the net amino acid uptake but stimulated amino acid incorporation into protein, although this response was less in LP animals than in control animals.3. In muscle from PF animals, GH stimulated both amino acid incorporation into protein and the net amino acid uptake, a type of response which also occurs in hypophysectomized animals. The magnitude of the effect of GH on the incorporation of amino acids into protein was reduced in muscle from PF animals.4. The effect of GH on the net amino acid uptake in PF animals was completely blocked by cycloheximide; the uptake effect of GH in these animals was dependent therefore on de novo protein synthesis.5. It is proposed that in the adult the role of growth hormone in protein metabolism is to sustain cellular protein synthesis when there is a decrease in the level of substrate amino acids, similar to that which occurs during a short-term fast or when the dietary protein intake is inadequate.

scholarly journals Biotin-mediated protein biosynthesis

1974 ◽  
Vol 140 (3) ◽  
pp. 549-556 ◽  
Author(s):  
R. L. Boeckx ◽  
K. Dakshinamurti
Keyword(s):  
Protein Synthesis ◽  
Amino Acid ◽  
Rat Liver ◽  
Intestinal Mucosa ◽  
Protein Biosynthesis ◽  
Amino Acid Incorporation ◽  
Acid Incorporation ◽  
Stimulation Of

The effect of administration of biotin to biotin-deficient rats on protein biosynthesis was studied. Biotin treatment resulted in stimulation by more than twofold of amino acid incorporation into protein, both in vivo and in vitro in rat liver, pancreas, intestinal mucosa and skin. Analysis of the products of amino acid incorporation into liver proteins in vivo and in vitro indicated that the synthesis of some proteins was stimulated more than twofold, but others were not stimulated at all. This indicates a specificity in the stimulation of protein synthesis mediated by biotin.

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