scholarly journals Fractionation of nuclear and cytoplasmic ribonucleic acids from rat tissues on the methylated albumin–kieselguhr column

1971 ◽  
Vol 125 (1) ◽  
pp. 225-234 ◽  
Author(s):  
A. V. Lichtenstein ◽  
V. S. Shapot
Keyword(s):  
Rat Liver ◽  
Selective Adsorption ◽  
Resolving Power ◽  
Rat Tissues ◽  
Preparative Scale ◽  
Ribonucleic Acids ◽  
Cytoplasmic Rna ◽  
Special Procedure ◽  
Cytoplasmic Dna ◽  
Nuclear Rna

1. The conformation of RNA was found to affect its behaviour on methylated albumin–kieselguhr chromatography. The less regular the secondary structure of RNA, the more tightly it binds to the methylated albumin–kieselguhr column. 2. The presence of various denaturing agents (such as urea or perchlorate) in the medium while RNA was adsorbed on the column increased the resolving power of the technique as exemplified by the separation of rat liver rRNA into two distinct peaks. A special procedure for selective adsorption of the cytoplasmic DNA-like RNA on the preparative scale has been developed. Polyribosomal mRNA (rapidly labelled RNA formed in the presence of small doses of actinomycin D) can also be adsorbed selectively by the column. 3. A type of tissue specificity was detected in nuclear RNA from rat liver, kidney, thymus and spleen by using a modified salt and temperature gradient for the chromatographic fractionation (Lichtenstein, Piker & Shapot, 1967; Shapot, Lichtenstein & Piker, 1967). It was also found that cytoplasmic RNA from the different rat tissues contained no tenaciously bound fraction at all, whereas it constituted about 50% of the nuclear RNA. The problem of the possible biological function of the tenaciously bound fraction is discussed.

scholarly journals Ribosomal and informational ribonucleoprotein complexes of animal cells. Study on rat liver ribonucleic acids as constituents of ribonucleoprotein complexes by chromatography on nucleoprotein-celite columns.

1975 ◽  
Vol 147 (3) ◽  
pp. 447-456 ◽  
Author(s):  
A V Lichtenstein ◽  
R P Alechina ◽  
V S Shapot
Keyword(s):  
Rat Liver ◽  
Gradient Elution ◽  
Animal Cells ◽  
Ribonucleic Acids ◽  
Rna Molecules ◽  
Ribonucleoprotein Complexes ◽  
Cytoplasmic Rna ◽  
Novel Method ◽  
Gradual Release ◽  
Linear Concentration

A novel method of RNA fractionation has been developed. Nuclear and cytoplasmic rat liver RNA species were fractionated as constituents of corresponding ribonucleoprotein particles, which were previously adsorbed on a Celite-column by their protein component. The fractionation is based on a dissociation of the particles (linear concentration gradient of LiCl and urea with subsequent temperature gradient), which results in a gradual release of the RNA molecules from ribonucleoprotein complexes. Thus the fractionation is in accordance with the tightness of the RNA-protein bonds. A gradient elution of RNA from a nucleoprotein-Celite column permitted fractionation of both ribosomal and rapidly labelled non-ribosomal RNA. The latter, both nuclear and cytoplasmic, could be separated by chromatography on nucleoprotein-Celite columns into two main fractions (components I and V). In cytoplasmic RNA components I and V presumably correspond to mlRNA (messenger-like RNA of free cytoplasmic particles) and mRNA (template RNA associated with ribosomes) respectively.

scholarly journals Re-utilization of pyrimidine nucleotides during rat liver regeneration

1985 ◽  
Vol 228 (1) ◽  
pp. 27-33 ◽  
Author(s):  
E N Nikolov ◽  
M D Dabeva
Keyword(s):  
Rat Liver ◽  
Rna Degradation ◽  
Total Acid ◽  
Pyrimidine Nucleotides ◽  
True Rate ◽  
Cytoplasmic Rna ◽  
Nuclear Rna ◽  
Rat Liver Cells ◽  
Ribonucleoside Triphosphate ◽  
Uridine Nucleotides

The changes in the specific radioactivities of the pool of total acid-soluble uridine nucleotides and of uridine and cytidine components of total cellular and nuclear RNA were monitored in regenerating rat liver for 12 days after partial hepatectomy. Evidence is presented for the re-utilization of pyrimidine nucleotides derived from cytoplasmic RNA degradation for the synthesis of new RNA. The extent of recycling was assessed and the true rate of rRNA turnover determined more accurately. The reutilization of the uridine components of RNA was 7.0%/day during the proliferative and 3.2%/day during the post-proliferative phase, whereas that of the cytidine nucleotides was more pronounced (9.6%/day and 18.1%/day respectively). The results reveal the existence of partial compartmentalization of pyrimidine ribonucleoside triphosphate pools in the nucleus and cytoplasm of rat liver cells.

scholarly journals Properties of subunits of the multicatalytic proteinase complex revealed by the use of subunit-specific antibodies

1991 ◽  
Vol 278 (1) ◽  
pp. 171-177 ◽  
Author(s):  
A J Rivett ◽  
S T Sweeney
Keyword(s):  
Molecular Mass ◽  
Rat Liver ◽  
Gel Filtration ◽  
Immunoblot Analysis ◽  
Rat Tissues ◽  
Specific Antibodies ◽  
Multicatalytic Proteinase ◽  
Cell Extracts ◽  
Liver And Kidney ◽  
Lysosomal Proteinase

The multicatalytic proteinase (MCP) is a high-molecular-mass non-lysosomal proteinase that gives rise to a characteristic pattern of bands of molecular mass 22-34 kDa on SDS/PAGE gels. Isoelectric-focusing gels of the enzyme purified from rat liver show 16 bands with isoelectric points in the range of pH 5-8.5. Two-dimensional PAGE gels reveal that there are more than the previously reported 13 polypeptides associated with the MCP from rat liver and show a pattern of 15-20 major spots and several minor ones, similar to that of MCP isolated from some other sources. Possible relationships between the different polypeptides were investigated by immunoblot analysis of electrophoretically purified proteinase subunits with affinity-purified subunit-specific antibodies as well as antibodies raised against individual denatured subunits of the complex. The results demonstrate that many of the major polypeptide components of the MCP complex are antigenically distinct. Moreover comparison of immunoreactive material in crude cell extracts with that in purified MCP preparations has shown that the polypeptides are not derived from a smaller number of higher-molecular-mass subunits. Also, individual subunits have the same apparent molecular mass in a variety of rat tissues, suggesting close similarity between MCPs of different tissues. The highest concentrations of MCP subunits occur in liver and kidney. Gel-filtration analysis of crude extracts has demonstrated that MCP polypeptides are also associated with a higher-molecular-mass complex, which may be the 26 S proteinase that has been implicated in the degradation of ubiquitin-protein conjugates.

INACTIVATION AND DEGRADATION OF PORCINE CALCITONIN BY RAT LIVER, AND RELATIVE STABILITY OF SALMON CALCITONIN

1970 ◽  
Vol 48 (2) ◽  
pp. 181-188 ◽  
Author(s):  
M. de LUISE ◽  
T. J. MARTIN ◽  
R. A. MELICK
Keyword(s):  
Biological Activity ◽  
Rat Liver ◽  
Salmon Calcitonin ◽  
Trichloroacetic Acid ◽  
Maximal Activity ◽  
Active Principle ◽  
Rat Tissues ◽  
Prolonged Action ◽  
High Potency ◽  
Dose Dependent

SUMMARY Slices and homogenates of a number of rat tissues inactivated porcine calcitonin labelled with 125I; the most active tissue was the liver. Maximal activity was found in rat liver supernatant. The reaction was pH- and dose-dependent, the active principle was non-diffusible, inhibited by p-chloromercuribenzoate and EDTA, and destroyed by heat. Biological activity of calcitonin was lost parallel with the breakdown of the labelled calcitonin (as measured by loss of trichloroacetic acid precipitability). Salmon ultimobranchial calcitonin was much less susceptible to inactivation by rat liver supernatant than the porcine hormone, which may explain the high potency and prolonged action of the salmon hormone in the rat.

Effect of Irradiation on the Biosynthesis of Liver Ribonucleic acids in Intact and Adrenalectomized Rats

1971 ◽  
Vol 26 (12) ◽  
pp. 1282-1287 ◽  
Author(s):  
P. G. Popov ◽  
L. I. Valeva-Dimitrova ◽  
A. A. Hadjiolov
Keyword(s):  
Rna Synthesis ◽  
Whole Body ◽  
Agar Gel ◽  
Ribonucleic Acids ◽  
Cytoplasmic Rna ◽  
Combined Action ◽  
Agar Gel Electrophoresis ◽  
Uridine Nucleotides ◽  
Adrenalectomized Rats ◽  
Hydrocortisone Treatment

Intact and adrenalectomized rats were irradiated with 900 R or treated with 10 mg per 100 g body weight of hydrocortisone. The incorporation of orotic acid-6-14C for 2 hours into liver free uridine nucleotides, nuclear and cytoplasmic RNA and RNA fractions obtained by agar gel electrophoresis, were studied.The obtained results show that in intact animals both irradiation and hydrocortisone induce a higher labelling of cytoplasmic and nuclear liver RNA. The higher labelling of RNA is not correlated with a higher labelling of the free uridine nucleotides. The labelling of all electrophoretic RNA fractions is increased to approximately the same extent under the action of either hydrocortisone or irradiation.Irradiation or hydrocortisone treatment of adrenalectomized rats causes also a higher labelling of liver nuclear and cytoplasmic RNA. The higher labelling of RNA is not correlated with that of free uridine nucleotides and affects all electrophoretic RNA fractions.. The combined action of irradiation and hydrocortisone shows an additive effect on the labelling of nuclear and cytoplasmic liver RNA.The obtained results indicate that whole body irradiation causes an increased synthesis of both ribosomal and non-ribosomal RNA’s of rat liver. Since the same effect is observed in intact and adrenalectomized animals it may be concluded that the stimulation of liver RNA synthesis by irradiation is not mediated by the adrenals.

scholarly journals Effects of the hepatotoxic agents retrorsine and aflatoxin B1 on hepatic protein synthesis in the rat

1968 ◽  
Vol 109 (1) ◽  
pp. 87-91 ◽  
Author(s):  
S. Villa-Treviño ◽  
D. D. Leaver
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Rat Liver ◽  
Aflatoxin B1 ◽  
Plasma Proteins ◽  
Pyrrolizidine Alkaloid ◽  
Main Site ◽  
Nuclear Rna ◽  
Hepatic Protein Synthesis

1. Aflatoxin and the pyrrolizidine alkaloid retrorsine inhibited the incorporation of labelled amino acids into rat liver and plasma proteins in vivo. Inhibition was greater and detected earlier with retrorsine (1hr.) than with aflatoxin (3hr.). 2. Both toxins affected the liver ribosomal aggregates, causing increases in the proportion of monomers plus dimers. The effect of retrorsine was greater than that of aflatoxin. 3. Incorporation of labelled amino acids into proteins of cell-free preparations of liver from rats treated with aflatoxin was lower than in control preparations. The main site of inhibition appeared to be the ribosomes. 4. Both toxins inhibited the incorporation of orotate into liver nuclear RNA 1hr. after administration.

Sign in / Sign up

Export Citation Format

Share Document