STRUCTURAL ALTERATION IN ISOLATED RAT LIVER NUCLEI AFTER REMOVAL OF TEMPLATE RESTRICTION BY POLYANIONS

Structural Alteration in Isolated Rat Liver Nuclei after Removal of Template Restriction by Polyanions

Specific polyanions release DNA template restrictions for DNA synthesis in isolated rat liver nuclei. The degree to which DNA synthesis is enhanced can be correlated with a spectrum of changes in nuclear structure Each polyanion which is effective in the release of template restriction produces a characteristic alteration in nuclear ultrastructure. Polyanions which have no effect on DNA synthes...

The metabolism of isolated rat-liver nuclei.

The investigations described in this paper were undertaken as a preliminary to the study of the biochemical changes in the nucleus of the rat-liver cell during the induction of liver cancer. Allfrey (1954) and Stern & Mirsky (1953) described the isolation in aqueous media of nuclei from the thymus gland of the calf. Such preparations in vitro incorporated glycine and other amino acids into nucl...

Modulation by exogenous histones of phosphorylation of non-histone nuclear proteins in isolated rat liver nuclei.

The phosphorylation of specific non-histone proteins in isolated rat liver nuclei is modified by the addition of exogenous histone fractions. The added histones are quantitatively adsorbed and their presence in the chromatin has been verified by electron microscope autoradiography. Histone fractions Fl and FZAl stimulate phosphorylation of different nuclear phosphoproteins. Fl stimulates the ph...

Alteration of tumor response in rat liver by carbon tetrachloride.

Synthesis of deoxyribonucleic acid by isolated liver nuclei.

The incorporation of 3H-TTP into the DNA of intact nuclei isolated from the livers of normal and partially hepatectomized rats has been studied. The regenerating nuclei incorporate 3H-TTP at about 10 times the rate of normal nuclei. The requirements for a maximal rate of incorporation include the three unlabeled deoxynucleoside triphosphates, ATP, and Mg++. Three pieces of evidence are presente...