Cargando…
Nonproductive Splicing Prevents Expression of MYH7b Protein in the Mammalian Heart
BACKGROUND: Although the roles of alpha‐myosin heavy chain (α‐MyHC) and beta‐myosin heavy chain (β‐MyHC) proteins in cardiac contractility have long been appreciated, the biological contribution of another closely related sarcomeric myosin family member, MYH7b (myosin heavy chain 7b), has become a m...
Autores principales: | , , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
John Wiley and Sons Inc.
2021
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8483497/ https://www.ncbi.nlm.nih.gov/pubmed/34227390 http://dx.doi.org/10.1161/JAHA.121.020965 |
_version_ | 1784577141845786624 |
---|---|
author | Lee, Lindsey A. Broadwell, Lindsey J. Buvoli, Massimo Leinwand, Leslie A. |
author_facet | Lee, Lindsey A. Broadwell, Lindsey J. Buvoli, Massimo Leinwand, Leslie A. |
author_sort | Lee, Lindsey A. |
collection | PubMed |
description | BACKGROUND: Although the roles of alpha‐myosin heavy chain (α‐MyHC) and beta‐myosin heavy chain (β‐MyHC) proteins in cardiac contractility have long been appreciated, the biological contribution of another closely related sarcomeric myosin family member, MYH7b (myosin heavy chain 7b), has become a matter of debate. In mammals, MYH7b mRNA is transcribed but undergoes non‐productive alternative splicing that prevents protein expression in a tissue‐specific manner, including in the heart. However, several studies have recently linked MYH7b variants to different cardiomyopathies or have reported MYH7b protein expression in mammalian hearts. METHODS AND RESULTS: By analyzing mammalian cardiac transcriptome and proteome data, we show that the vast majority of MYH7b RNA is subject to exon skipping and cannot be translated into a functional myosin molecule. Notably, we discovered a lag in the removal of introns flanking the alternatively spliced exon, which could retain the non‐coding RNA in the nucleus. This process could play a significant role in controlling MYH7b expression as well as the activity of other cardiac genes. Consistent with the negligible level of full‐length protein coding mRNA, no MYH7b protein expression was detected in adult mouse, rat, and human hearts by Western blot analysis. Furthermore, proteome surveys including quantitative mass spectrometry analyses revealed only traces of cardiac MYH7b protein and even then, only in a subset of individual samples. CONCLUSIONS: The comprehensive analysis presented here suggests that previous studies showing cardiac MYH7b protein expression were likely attributable to antibody cross‐reactivity. More importantly, our data predict that the MYH7b disease‐associated variants may operate through the alternately spliced RNA itself. |
format | Online Article Text |
id | pubmed-8483497 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2021 |
publisher | John Wiley and Sons Inc. |
record_format | MEDLINE/PubMed |
spelling | pubmed-84834972021-10-06 Nonproductive Splicing Prevents Expression of MYH7b Protein in the Mammalian Heart Lee, Lindsey A. Broadwell, Lindsey J. Buvoli, Massimo Leinwand, Leslie A. J Am Heart Assoc Original Research BACKGROUND: Although the roles of alpha‐myosin heavy chain (α‐MyHC) and beta‐myosin heavy chain (β‐MyHC) proteins in cardiac contractility have long been appreciated, the biological contribution of another closely related sarcomeric myosin family member, MYH7b (myosin heavy chain 7b), has become a matter of debate. In mammals, MYH7b mRNA is transcribed but undergoes non‐productive alternative splicing that prevents protein expression in a tissue‐specific manner, including in the heart. However, several studies have recently linked MYH7b variants to different cardiomyopathies or have reported MYH7b protein expression in mammalian hearts. METHODS AND RESULTS: By analyzing mammalian cardiac transcriptome and proteome data, we show that the vast majority of MYH7b RNA is subject to exon skipping and cannot be translated into a functional myosin molecule. Notably, we discovered a lag in the removal of introns flanking the alternatively spliced exon, which could retain the non‐coding RNA in the nucleus. This process could play a significant role in controlling MYH7b expression as well as the activity of other cardiac genes. Consistent with the negligible level of full‐length protein coding mRNA, no MYH7b protein expression was detected in adult mouse, rat, and human hearts by Western blot analysis. Furthermore, proteome surveys including quantitative mass spectrometry analyses revealed only traces of cardiac MYH7b protein and even then, only in a subset of individual samples. CONCLUSIONS: The comprehensive analysis presented here suggests that previous studies showing cardiac MYH7b protein expression were likely attributable to antibody cross‐reactivity. More importantly, our data predict that the MYH7b disease‐associated variants may operate through the alternately spliced RNA itself. John Wiley and Sons Inc. 2021-07-06 /pmc/articles/PMC8483497/ /pubmed/34227390 http://dx.doi.org/10.1161/JAHA.121.020965 Text en © 2021 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley. https://creativecommons.org/licenses/by-nc-nd/4.0/This is an open access article under the terms of the http://creativecommons.org/licenses/by-nc-nd/4.0/ (https://creativecommons.org/licenses/by-nc-nd/4.0/) License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non‐commercial and no modifications or adaptations are made. |
spellingShingle | Original Research Lee, Lindsey A. Broadwell, Lindsey J. Buvoli, Massimo Leinwand, Leslie A. Nonproductive Splicing Prevents Expression of MYH7b Protein in the Mammalian Heart |
title | Nonproductive Splicing Prevents Expression of MYH7b Protein in the Mammalian Heart |
title_full | Nonproductive Splicing Prevents Expression of MYH7b Protein in the Mammalian Heart |
title_fullStr | Nonproductive Splicing Prevents Expression of MYH7b Protein in the Mammalian Heart |
title_full_unstemmed | Nonproductive Splicing Prevents Expression of MYH7b Protein in the Mammalian Heart |
title_short | Nonproductive Splicing Prevents Expression of MYH7b Protein in the Mammalian Heart |
title_sort | nonproductive splicing prevents expression of myh7b protein in the mammalian heart |
topic | Original Research |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8483497/ https://www.ncbi.nlm.nih.gov/pubmed/34227390 http://dx.doi.org/10.1161/JAHA.121.020965 |
work_keys_str_mv | AT leelindseya nonproductivesplicingpreventsexpressionofmyh7bproteininthemammalianheart AT broadwelllindseyj nonproductivesplicingpreventsexpressionofmyh7bproteininthemammalianheart AT buvolimassimo nonproductivesplicingpreventsexpressionofmyh7bproteininthemammalianheart AT leinwandlesliea nonproductivesplicingpreventsexpressionofmyh7bproteininthemammalianheart |