Distinct hypertrophic cardiomyopathy genotypes result in convergent sarcomeric proteoform profiles revealed by top-down proteomics

Tucholski, Trisha and Cai, Wenxuan and Gregorich, Zachery R. and Bayne, Elizabeth F. and Mitchell, Stanford D. and McIlwain, Sean J. and de Lange, Willem J. and Wrobbel, Max and Karp, Hannah and Hite, Zachary and Vikhorev, Petr G. and Marston, Steven B. and Lal, Sean and Li, Amy and dos Remedios, Cristobal and Kohmoto, Takushi and Hermsen, Joshua and Ralphe, J. Carter and Kamp, Timothy J. and Moss, Richard L. and Ge, Ying (2020) Distinct hypertrophic cardiomyopathy genotypes result in convergent sarcomeric proteoform profiles revealed by top-down proteomics. Proceedings of the National Academy of Sciences, 117 (40). pp.24691-24700. ISSN 0027-8424

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Link to published document: http://doi.org/10.1073/pnas.2006764117


Hypertrophic cardiomyopathy (HCM) is the most common heritable heart disease. Although the genetic cause of HCM has been linked to mutations in genes encoding sarcomeric proteins, the ability to predict clinical outcomes based on specific mutations in HCM patients is limited. Moreover, how mutations in different sarcomeric proteins can result in highly similar clinical phenotypes remains unknown. Posttranslational modifications (PTMs) and alternative splicing regulate the function of sarcomeric proteins; hence, it is critical to study HCM at the level of proteoforms to gain insights into the mechanisms underlying HCM. Herein, we employed high-resolution mass spectrometry-based top-down proteomics to comprehensively characterize sarcomeric proteoforms in septal myectomy tissues from HCM patients exhibiting severe outflow track obstruction (n = 16) compared to nonfailing donor hearts (n = 16). We observed a complex landscape of sarcomeric proteoforms arising from combinatorial PTMs, alternative splicing, and genetic variation in HCM. A coordinated decrease of phosphorylation in important myofilament and Z-disk proteins with a linear correlation suggests PTM cross-talk in the sarcomere and dysregulation of protein kinase A pathways in HCM. Strikingly, we discovered that the sarcomeric proteoform alterations in the myocardium of HCM patients undergoing septal myectomy were remarkably consistent, regardless of the underlying HCM-causing mutations. This study suggests that the manifestation of severe HCM coalesces at the proteoform level despite distinct genotype, which underscores the importance of molecular characterization of HCM phenotype and presents an opportunity to identify broad-spectrum treatments to mitigate the most severe manifestations of this genetically heterogenous disease.

Item Type: Article
Subjects: R Medicine > R Medicine (General)
Depositing User: Repository Administrator
Date Deposited: 28 Oct 2021 02:06
Last Modified: 28 Oct 2021 02:06
URI: http://eprints.victorchang.edu.au/id/eprint/1157

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