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Membrane changes during cartilage maturation. Increase in 5'- nucleotidase and decrease in adenosine inhibition of adenylate cyclase

To examine the potential participation of the plasma membrane in differentiation, we studied the enzymatic activities of 5'-nucleotidase and adenylate cyclase as a function of chondrocyte maturation. 16-day- old chick embryo tibiae epiphyses were dissected into proliferative, growing and hypert...

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Detalles Bibliográficos
Formato: Texto
Lenguaje:English
Publicado: The Rockefeller University Press 1977
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2111015/
https://www.ncbi.nlm.nih.gov/pubmed/833206
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description To examine the potential participation of the plasma membrane in differentiation, we studied the enzymatic activities of 5'-nucleotidase and adenylate cyclase as a function of chondrocyte maturation. 16-day- old chick embryo tibiae epiphyses were dissected into proliferative, growing and hypertrophying zones. Partially purified membrane fractions prepared by differential centrifugation from the respective tissue segments were assayed for enzymatic activity. Cell suspensions from the same segments were examined cytochemically for the presence of 5'- nucleotidase. The findings show that the 5'-nucleotidase activity of the chick embryo epiphyseal cartilage has the following characteristics: (a) it has a Km of about 25 muM for 5'AMP, and is inhibited by a mixture of 2' and 3'AMP (apparent Ki about 10(-4) M) and by AOPCP; (b) it is predominantly localized at the cell surface but is also detected in the cytoplasm and in association with nuclear heterochromatin; and (c) it increases 10-fold (on a DNA basis) during the maturation of the epiphyseal cartilage cells. The adenylate cyclase activity has these characteristics: (a) it does not change during chondrocyte maturation (on a DNA basis); (b) its susceptibility to adenosine inhibition decreases at least 10-fold. The implication of these findings relative to a possible role of adenosine in cellular communication is discussed.
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spelling pubmed-21110152008-05-01 Membrane changes during cartilage maturation. Increase in 5'- nucleotidase and decrease in adenosine inhibition of adenylate cyclase J Cell Biol Articles To examine the potential participation of the plasma membrane in differentiation, we studied the enzymatic activities of 5'-nucleotidase and adenylate cyclase as a function of chondrocyte maturation. 16-day- old chick embryo tibiae epiphyses were dissected into proliferative, growing and hypertrophying zones. Partially purified membrane fractions prepared by differential centrifugation from the respective tissue segments were assayed for enzymatic activity. Cell suspensions from the same segments were examined cytochemically for the presence of 5'- nucleotidase. The findings show that the 5'-nucleotidase activity of the chick embryo epiphyseal cartilage has the following characteristics: (a) it has a Km of about 25 muM for 5'AMP, and is inhibited by a mixture of 2' and 3'AMP (apparent Ki about 10(-4) M) and by AOPCP; (b) it is predominantly localized at the cell surface but is also detected in the cytoplasm and in association with nuclear heterochromatin; and (c) it increases 10-fold (on a DNA basis) during the maturation of the epiphyseal cartilage cells. The adenylate cyclase activity has these characteristics: (a) it does not change during chondrocyte maturation (on a DNA basis); (b) its susceptibility to adenosine inhibition decreases at least 10-fold. The implication of these findings relative to a possible role of adenosine in cellular communication is discussed. The Rockefeller University Press 1977-02-01 /pmc/articles/PMC2111015/ /pubmed/833206 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/).
spellingShingle Articles
Membrane changes during cartilage maturation. Increase in 5'- nucleotidase and decrease in adenosine inhibition of adenylate cyclase
title Membrane changes during cartilage maturation. Increase in 5'- nucleotidase and decrease in adenosine inhibition of adenylate cyclase
title_full Membrane changes during cartilage maturation. Increase in 5'- nucleotidase and decrease in adenosine inhibition of adenylate cyclase
title_fullStr Membrane changes during cartilage maturation. Increase in 5'- nucleotidase and decrease in adenosine inhibition of adenylate cyclase
title_full_unstemmed Membrane changes during cartilage maturation. Increase in 5'- nucleotidase and decrease in adenosine inhibition of adenylate cyclase
title_short Membrane changes during cartilage maturation. Increase in 5'- nucleotidase and decrease in adenosine inhibition of adenylate cyclase
title_sort membrane changes during cartilage maturation. increase in 5'- nucleotidase and decrease in adenosine inhibition of adenylate cyclase
topic Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2111015/
https://www.ncbi.nlm.nih.gov/pubmed/833206