Cytoplasmic contaminants in Triton X-100 washed rat liver nuclei — a possible way of further purification

1979 ◽  
Vol 35 (3) ◽  
pp. 328-330 ◽  
Author(s):  
C. Viticchi ◽  
F. Szeszák
Keyword(s):  
Rat Liver ◽  
Rat Liver Nuclei ◽  
Liver Nuclei ◽  
Triton X

scholarly journals ISOLATION OF TWO DISTINCT CLASSES OF POLYSOMES FROM A NUCLEAR FRACTION OF RAT LIVER

1968 ◽  
Vol 37 (1) ◽  
pp. 163-181 ◽  
Author(s):  
Paul D. Sadowski ◽  
Janet Alcock Howden
Keyword(s):  
Outer Membrane ◽  
Rat Liver ◽  
Orotic Acid ◽  
Specific Activity ◽  
Nuclear Fraction ◽  
Differential Centrifugation ◽  
Rat Liver Nuclei ◽  
Liver Nuclei ◽  
Triton X

Isolated rat liver nuclei were washed with Triton-X-100 in the presence of liver cell sap. This treatment liberated a fraction of polysomes which were isolated by differential centrifugation and were designated "outer membrane polysomes." The outer membrane polysomes synthesized protein in vivo. Shortly after injection of orotic acid-14C, the RNA of outer membrane polysomes had a higher specific activity than that of cytoplasmic polysomes. It was postulated that outer membrane polysomes may be an intermediate in the transfer of newly synthesized RNA from the nucleus to the cytoplasm. In other experiments, Triton-washed rat liver nuclei were lysed in the presence of deoxycholate and deoxyribonuclease. A ribonucleoprotein fraction was isolated from the lysate by differential centrifugation. This fraction contained "intranuclear ribosomes," which sedimented like partially degraded polysomes in sucrose gradients. This degradation could be partially prevented if intranuclear ribosomes were purified by sedimentation through heavy sucrose. The resulting pellets were termed "intranuclear polysomes" because they contained some undergraded polysomes. Intranuclear polysomes were highly radioactive after a brief pulse with orotic acid-14C, but did not appear to synthesize protein rapidly in vivo. Intranuclear polysomes may represent the initial stage of assembly of polyribosomes in the nucleus.

scholarly journals Phosphoinositide signalling enzymes in rat liver nuclei: phosphoinositidase C isoform β1 is specifically, but not predominantly, located in the nucleus

1993 ◽  
Vol 289 (3) ◽  
pp. 617-620 ◽  
Author(s):  
N Divecha ◽  
S G Rhee ◽  
A J Letcher ◽  
R F Irvine
Keyword(s):  
Nuclear Envelope ◽  
Rat Liver ◽  
Rat Liver Nuclei ◽  
Liver Nuclei ◽  
G Alpha Q ◽  
Triton X ◽  
Total Beta

The presence of phosphoinositide-mobilizing enzymes has been investigated in purified rat liver nuclei by radiolabelling and by probing with antibodies. A Ca(2+)-activated phosphoinositidase C (PIC) is present and was shown immunologically to be the beta 1 isoform. No gamma- or delta-PIC was found. However, only 5% of the total beta 1-PIC isoform is nuclear, with the majority being cytosolic. G alpha q and G alpha 11, the suggested physiological activators of beta 1-PIC, were not present. A PtdIns4P 5-kinase is also present, which immunologically is shown to be the C isoform. All of these nuclear inositide enzymes still remained after the removal of the nuclear envelope with Triton X-100, consistent with the concept of an intranuclear inositide cycle [Divecha, Banfic and Irvine (1991) EMBO. J. 10, 3207-3214].

Labelling of Proteins by Isolated Rat Liver Nuclei

1972 ◽  
Vol 50 (2) ◽  
pp. 190-199 ◽  
Author(s):  
K. M. Anderson ◽  
M. Slavik ◽  
O. P. Elebute
Keyword(s):  
Protein Synthesis ◽  
Rat Liver ◽  
Nuclear Protein ◽  
Sucrose Solution ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Rat Liver Nuclei ◽  
Teleological Argument ◽  
Liver Nuclei ◽  
Triton X

Rat liver nuclei, isolated in hypertonic sucrose solution and washed with Triton X-100, incorporate radioactive amino acids into hot trichloroacetic acid insoluble materials.Optical and biochemical evidence of nuclear purity is presented. The temperature-dependent incorporation continued for 20–30 min, and was proportional to the concentrations of both nuclear protein between 0.5–1.5 mg/ml, and radioactive amino acid. The radioactive product was degraded by pronase, and a number of inhibitors reduced incorporation, but only if present at [Formula: see text]. Proteins extracted from labelled nuclei and microsomes and examined by sodium dodecyl sulfate–polyacrylamide gel electrophoresis at pH 7.2 exhibited different patterns of radioactivity. This provides further support for the concept of protein synthesis intrinsic to rat liver nuclei.A teleological argument for the function of nuclear protein synthesis is discussed.

scholarly journals Modulation by Exogenous Histones of Phosphorylation of Non-Histone Nuclear Proteins in Isolated Rat Liver Nuclei

1973 ◽  
Vol 248 (21) ◽  
pp. 7595-7600
Author(s):  
Edward M. Johnson ◽  
Giorgio Vidali ◽  
Virginia C. Littau ◽  
Vincent G. Allfrey
Keyword(s):  
Rat Liver ◽  
Nuclear Proteins ◽  
Isolated Rat Liver ◽  
Rat Liver Nuclei ◽  
Liver Nuclei ◽  
Isolated Rat
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