Cargando…
Different Localizations and Cellular Behaviors of Leiomodin and Tropomodulin in Mature Cardiomyocyte Sarcomeres
Leiomodin (Lmod) is a muscle-specific F-actin–nucleating protein that is related to the F-actin pointed-end–capping protein tropomodulin (Tmod). However, Lmod contains a unique ∼150-residue C-terminal extension that is required for its strong nucleating activity. Overexpression or depletion of Lmod...
Autores principales: | , , , , , , |
---|---|
Formato: | Texto |
Lenguaje: | English |
Publicado: |
The American Society for Cell Biology
2010
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2947471/ https://www.ncbi.nlm.nih.gov/pubmed/20685966 http://dx.doi.org/10.1091/mbc.E10-02-0109 |
_version_ | 1782187373146144768 |
---|---|
author | Skwarek-Maruszewska, Aneta Boczkowska, Malgorzata Zajac, Allison L. Kremneva, Elena Svitkina, Tatyana Dominguez, Roberto Lappalainen, Pekka |
author_facet | Skwarek-Maruszewska, Aneta Boczkowska, Malgorzata Zajac, Allison L. Kremneva, Elena Svitkina, Tatyana Dominguez, Roberto Lappalainen, Pekka |
author_sort | Skwarek-Maruszewska, Aneta |
collection | PubMed |
description | Leiomodin (Lmod) is a muscle-specific F-actin–nucleating protein that is related to the F-actin pointed-end–capping protein tropomodulin (Tmod). However, Lmod contains a unique ∼150-residue C-terminal extension that is required for its strong nucleating activity. Overexpression or depletion of Lmod compromises sarcomere organization, but the mechanism by which Lmod contributes to myofibril assembly is not well understood. We show that Tmod and Lmod localize through fundamentally different mechanisms to the pointed ends of two distinct subsets of actin filaments in myofibrils. Tmod localizes to two narrow bands immediately adjacent to M-lines, whereas Lmod displays dynamic localization to two broader bands, which are generally more separated from M-lines. Lmod's localization and F-actin nucleation activity are enhanced by interaction with tropomyosin. Unlike Tmod, the myofibril localization of Lmod depends on sustained muscle contraction and actin polymerization. We further show that Lmod expression correlates with the maturation of myofibrils in cultured cardiomyocytes and that it associates with sarcomeres only in differentiated myofibrils. Collectively, the data suggest that Lmod contributes to the final organization and maintenance of sarcomere architecture by promoting tropomyosin-dependent actin filament nucleation. |
format | Text |
id | pubmed-2947471 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2010 |
publisher | The American Society for Cell Biology |
record_format | MEDLINE/PubMed |
spelling | pubmed-29474712010-12-16 Different Localizations and Cellular Behaviors of Leiomodin and Tropomodulin in Mature Cardiomyocyte Sarcomeres Skwarek-Maruszewska, Aneta Boczkowska, Malgorzata Zajac, Allison L. Kremneva, Elena Svitkina, Tatyana Dominguez, Roberto Lappalainen, Pekka Mol Biol Cell Articles Leiomodin (Lmod) is a muscle-specific F-actin–nucleating protein that is related to the F-actin pointed-end–capping protein tropomodulin (Tmod). However, Lmod contains a unique ∼150-residue C-terminal extension that is required for its strong nucleating activity. Overexpression or depletion of Lmod compromises sarcomere organization, but the mechanism by which Lmod contributes to myofibril assembly is not well understood. We show that Tmod and Lmod localize through fundamentally different mechanisms to the pointed ends of two distinct subsets of actin filaments in myofibrils. Tmod localizes to two narrow bands immediately adjacent to M-lines, whereas Lmod displays dynamic localization to two broader bands, which are generally more separated from M-lines. Lmod's localization and F-actin nucleation activity are enhanced by interaction with tropomyosin. Unlike Tmod, the myofibril localization of Lmod depends on sustained muscle contraction and actin polymerization. We further show that Lmod expression correlates with the maturation of myofibrils in cultured cardiomyocytes and that it associates with sarcomeres only in differentiated myofibrils. Collectively, the data suggest that Lmod contributes to the final organization and maintenance of sarcomere architecture by promoting tropomyosin-dependent actin filament nucleation. The American Society for Cell Biology 2010-10-01 /pmc/articles/PMC2947471/ /pubmed/20685966 http://dx.doi.org/10.1091/mbc.E10-02-0109 Text en © 2010 by The American Society for Cell Biology This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0). |
spellingShingle | Articles Skwarek-Maruszewska, Aneta Boczkowska, Malgorzata Zajac, Allison L. Kremneva, Elena Svitkina, Tatyana Dominguez, Roberto Lappalainen, Pekka Different Localizations and Cellular Behaviors of Leiomodin and Tropomodulin in Mature Cardiomyocyte Sarcomeres |
title | Different Localizations and Cellular Behaviors of Leiomodin and Tropomodulin in Mature Cardiomyocyte Sarcomeres |
title_full | Different Localizations and Cellular Behaviors of Leiomodin and Tropomodulin in Mature Cardiomyocyte Sarcomeres |
title_fullStr | Different Localizations and Cellular Behaviors of Leiomodin and Tropomodulin in Mature Cardiomyocyte Sarcomeres |
title_full_unstemmed | Different Localizations and Cellular Behaviors of Leiomodin and Tropomodulin in Mature Cardiomyocyte Sarcomeres |
title_short | Different Localizations and Cellular Behaviors of Leiomodin and Tropomodulin in Mature Cardiomyocyte Sarcomeres |
title_sort | different localizations and cellular behaviors of leiomodin and tropomodulin in mature cardiomyocyte sarcomeres |
topic | Articles |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2947471/ https://www.ncbi.nlm.nih.gov/pubmed/20685966 http://dx.doi.org/10.1091/mbc.E10-02-0109 |
work_keys_str_mv | AT skwarekmaruszewskaaneta differentlocalizationsandcellularbehaviorsofleiomodinandtropomodulininmaturecardiomyocytesarcomeres AT boczkowskamalgorzata differentlocalizationsandcellularbehaviorsofleiomodinandtropomodulininmaturecardiomyocytesarcomeres AT zajacallisonl differentlocalizationsandcellularbehaviorsofleiomodinandtropomodulininmaturecardiomyocytesarcomeres AT kremnevaelena differentlocalizationsandcellularbehaviorsofleiomodinandtropomodulininmaturecardiomyocytesarcomeres AT svitkinatatyana differentlocalizationsandcellularbehaviorsofleiomodinandtropomodulininmaturecardiomyocytesarcomeres AT dominguezroberto differentlocalizationsandcellularbehaviorsofleiomodinandtropomodulininmaturecardiomyocytesarcomeres AT lappalainenpekka differentlocalizationsandcellularbehaviorsofleiomodinandtropomodulininmaturecardiomyocytesarcomeres |