STUDIES ON THE FUNCTION OF INTRACELLULAR RIBONUCLEASES : V. Ribonuclease Activity in Ribosomes and Polysomes Prepared from Rat Liver and Hepatomas

STUDIES ON THE FUNCTION OF INTRACELLULAR RIBONUCLEASES : V. Ribonuclease Activity in Ribosomes and Polysomes Prepared from Rat Liver and Hepatomas

The RNase activity and properties of ribosome and polysome preparations from normal rat liver and some hepatomas have been examined. Polysome and ribosome preparations from the Novikoff, McCoy MDAB, and Dunning hepatomas had considerably higher specific RNase activity than corresponding preparation...

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Main Authors: Utsunomiya, Takeshi, Roth, Jay S.
Format: Online
Language:English
Published: The Rockefeller University Press 1966
Online Access:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2106969/
id pubmed-2106969
recordtype oai_dc
spelling pubmed-21069692008-05-01 STUDIES ON THE FUNCTION OF INTRACELLULAR RIBONUCLEASES : V. Ribonuclease Activity in Ribosomes and Polysomes Prepared from Rat Liver and Hepatomas Utsunomiya, Takeshi Roth, Jay S. Article The RNase activity and properties of ribosome and polysome preparations from normal rat liver and some hepatomas have been examined. Polysome and ribosome preparations from the Novikoff, McCoy MDAB, and Dunning hepatomas had considerably higher specific RNase activity than corresponding preparations from normal rat liver, Novikoff ascites, or Morris 5123 hepatomas. The optimum pH of the RNase was approximately 8.5 for all samples tested, and the samples showed no evidence of latent RNase activity when treated with 3 M sodium chloride, EDTA, urea, or p-chloromercuribenzenesulfonic acid. The RNase activity appeared to be associated principally with breakdown products and/or subunits smaller than 80S. In the presence of Mg++ ions, subunits could reaggregate to form monomer ribosomes indistinguishable from the natural products, but some of the reassociated ribosomes could contain RNase activity which had been bound to the smaller particles. Similar results were obtained with spermine. In the hepatomas, evidence was obtained for the preexistence of considerable amounts of the smaller, RNase-containing subunits in the cell. When a small amount of crystalline bovine pancreatic RNase was added to partly dissociated ribosomes, the RNase was found only in association with the smaller subunits, and little or no enzyme was taken up by ribosomes or polysomes. The results have led to the conclusion that RNase is not a normal constituent of the ribosome or polysome, but that RNase may become associated with these particulates if dissociation and reassociation take place. Some implications of these findings for the stability of messenger RNA and for the mechanism of its breakdown are discussed. The Rockefeller University Press 1966-06-01 /pmc/articles/PMC2106969/ /pubmed/4289964 Text en This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/4.0/).
repository_type Open Access Journal
institution_category Foreign Institution
institution US National Center for Biotechnology Information
building NCBI PubMed
collection Online Access
language English
format Online
author Utsunomiya, Takeshi
Roth, Jay S.
spellingShingle Utsunomiya, Takeshi
Roth, Jay S.
STUDIES ON THE FUNCTION OF INTRACELLULAR RIBONUCLEASES : V. Ribonuclease Activity in Ribosomes and Polysomes Prepared from Rat Liver and Hepatomas
author_facet Utsunomiya, Takeshi
Roth, Jay S.
author_sort Utsunomiya, Takeshi
title STUDIES ON THE FUNCTION OF INTRACELLULAR RIBONUCLEASES : V. Ribonuclease Activity in Ribosomes and Polysomes Prepared from Rat Liver and Hepatomas
title_short STUDIES ON THE FUNCTION OF INTRACELLULAR RIBONUCLEASES : V. Ribonuclease Activity in Ribosomes and Polysomes Prepared from Rat Liver and Hepatomas
title_full STUDIES ON THE FUNCTION OF INTRACELLULAR RIBONUCLEASES : V. Ribonuclease Activity in Ribosomes and Polysomes Prepared from Rat Liver and Hepatomas
title_fullStr STUDIES ON THE FUNCTION OF INTRACELLULAR RIBONUCLEASES : V. Ribonuclease Activity in Ribosomes and Polysomes Prepared from Rat Liver and Hepatomas
title_full_unstemmed STUDIES ON THE FUNCTION OF INTRACELLULAR RIBONUCLEASES : V. Ribonuclease Activity in Ribosomes and Polysomes Prepared from Rat Liver and Hepatomas
title_sort studies on the function of intracellular ribonucleases : v. ribonuclease activity in ribosomes and polysomes prepared from rat liver and hepatomas
description The RNase activity and properties of ribosome and polysome preparations from normal rat liver and some hepatomas have been examined. Polysome and ribosome preparations from the Novikoff, McCoy MDAB, and Dunning hepatomas had considerably higher specific RNase activity than corresponding preparations from normal rat liver, Novikoff ascites, or Morris 5123 hepatomas. The optimum pH of the RNase was approximately 8.5 for all samples tested, and the samples showed no evidence of latent RNase activity when treated with 3 M sodium chloride, EDTA, urea, or p-chloromercuribenzenesulfonic acid. The RNase activity appeared to be associated principally with breakdown products and/or subunits smaller than 80S. In the presence of Mg++ ions, subunits could reaggregate to form monomer ribosomes indistinguishable from the natural products, but some of the reassociated ribosomes could contain RNase activity which had been bound to the smaller particles. Similar results were obtained with spermine. In the hepatomas, evidence was obtained for the preexistence of considerable amounts of the smaller, RNase-containing subunits in the cell. When a small amount of crystalline bovine pancreatic RNase was added to partly dissociated ribosomes, the RNase was found only in association with the smaller subunits, and little or no enzyme was taken up by ribosomes or polysomes. The results have led to the conclusion that RNase is not a normal constituent of the ribosome or polysome, but that RNase may become associated with these particulates if dissociation and reassociation take place. Some implications of these findings for the stability of messenger RNA and for the mechanism of its breakdown are discussed.
publisher The Rockefeller University Press
publishDate 1966
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2106969/
_version_ 1611409226992713728

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