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Thin Filament Protein Dynamics in Fully Differentiated Adult Cardiac Myocytes: Toward A Model of Sarcomere Maintenance
Sarcomere maintenance, the continual process of replacement of contractile proteins of the myofilament lattice with newly synthesized proteins, in fully differentiated contractile cells is not well understood. Adenoviral-mediated gene transfer of epitope-tagged tropomyosin (Tm) and troponin I (TnI)...
Autores principales: | , , |
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Formato: | Texto |
Lenguaje: | English |
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The Rockefeller University Press
1999
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2133172/ https://www.ncbi.nlm.nih.gov/pubmed/10385527 |
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author | Michele, Daniel E. Albayya, Faris P. Metzger, Joseph M. |
author_facet | Michele, Daniel E. Albayya, Faris P. Metzger, Joseph M. |
author_sort | Michele, Daniel E. |
collection | PubMed |
description | Sarcomere maintenance, the continual process of replacement of contractile proteins of the myofilament lattice with newly synthesized proteins, in fully differentiated contractile cells is not well understood. Adenoviral-mediated gene transfer of epitope-tagged tropomyosin (Tm) and troponin I (TnI) into adult cardiac myocytes in vitro along with confocal microscopy was used to examine the incorporation of these newly synthesized proteins into myofilaments of a fully differentiated contractile cell. The expression of epitope-tagged TnI resulted in greater replacement of the endogenous TnI than the replacement of the endogenous Tm with the expressed epitope-tagged Tm suggesting that the rates of myofilament replacement are limited by the turnover of the myofilament bound protein. Interestingly, while TnI was first detected in cardiac sarcomeres along the entire length of the thin filament, the epitope-tagged Tm preferentially replaced Tm at the pointed end of the thin filament. These results support a model for sarcomeric maintenance in fully differentiated cardiac myocytes where (a) as myofilament proteins turnover within the cell they are rapidly exchanged with newly synthesized proteins, and (b) the nature of replacement of myofilament proteins (ordered or stochastic) is protein specific, primarily affected by the structural properties of the myofilament proteins, and may have important functional consequences. |
format | Text |
id | pubmed-2133172 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 1999 |
publisher | The Rockefeller University Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-21331722008-05-01 Thin Filament Protein Dynamics in Fully Differentiated Adult Cardiac Myocytes: Toward A Model of Sarcomere Maintenance Michele, Daniel E. Albayya, Faris P. Metzger, Joseph M. J Cell Biol Regular Articles Sarcomere maintenance, the continual process of replacement of contractile proteins of the myofilament lattice with newly synthesized proteins, in fully differentiated contractile cells is not well understood. Adenoviral-mediated gene transfer of epitope-tagged tropomyosin (Tm) and troponin I (TnI) into adult cardiac myocytes in vitro along with confocal microscopy was used to examine the incorporation of these newly synthesized proteins into myofilaments of a fully differentiated contractile cell. The expression of epitope-tagged TnI resulted in greater replacement of the endogenous TnI than the replacement of the endogenous Tm with the expressed epitope-tagged Tm suggesting that the rates of myofilament replacement are limited by the turnover of the myofilament bound protein. Interestingly, while TnI was first detected in cardiac sarcomeres along the entire length of the thin filament, the epitope-tagged Tm preferentially replaced Tm at the pointed end of the thin filament. These results support a model for sarcomeric maintenance in fully differentiated cardiac myocytes where (a) as myofilament proteins turnover within the cell they are rapidly exchanged with newly synthesized proteins, and (b) the nature of replacement of myofilament proteins (ordered or stochastic) is protein specific, primarily affected by the structural properties of the myofilament proteins, and may have important functional consequences. The Rockefeller University Press 1999-06-28 /pmc/articles/PMC2133172/ /pubmed/10385527 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 | Regular Articles Michele, Daniel E. Albayya, Faris P. Metzger, Joseph M. Thin Filament Protein Dynamics in Fully Differentiated Adult Cardiac Myocytes: Toward A Model of Sarcomere Maintenance |
title | Thin Filament Protein Dynamics in Fully Differentiated Adult Cardiac Myocytes: Toward A Model of Sarcomere Maintenance |
title_full | Thin Filament Protein Dynamics in Fully Differentiated Adult Cardiac Myocytes: Toward A Model of Sarcomere Maintenance |
title_fullStr | Thin Filament Protein Dynamics in Fully Differentiated Adult Cardiac Myocytes: Toward A Model of Sarcomere Maintenance |
title_full_unstemmed | Thin Filament Protein Dynamics in Fully Differentiated Adult Cardiac Myocytes: Toward A Model of Sarcomere Maintenance |
title_short | Thin Filament Protein Dynamics in Fully Differentiated Adult Cardiac Myocytes: Toward A Model of Sarcomere Maintenance |
title_sort | thin filament protein dynamics in fully differentiated adult cardiac myocytes: toward a model of sarcomere maintenance |
topic | Regular Articles |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2133172/ https://www.ncbi.nlm.nih.gov/pubmed/10385527 |
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