Alterations in cytoskeletal and Ca2+ cycling regulators in atria lacking the obscurin Ig58/59 module

IntroductionObscurin (720–870 kDa) is a giant cytoskeletal and signaling protein that possesses both structural and regulatory functions in striated muscles. Immunoglobulin domains 58/59 (Ig58/59) of obscurin bind to a diverse set of proteins that are essential for the proper structure and function...

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Main Authors: Alyssa Grogan, Weiliang Huang, Annie Brong, Maureen A. Kane, Aikaterini Kontrogianni-Konstantopoulos
Format: Article
Language:English
Published: Frontiers Media S.A. 2023-04-01
Series:Frontiers in Cardiovascular Medicine
Subjects:
Online Access:https://www.frontiersin.org/articles/10.3389/fcvm.2023.1085840/full
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author Alyssa Grogan
Weiliang Huang
Annie Brong
Maureen A. Kane
Aikaterini Kontrogianni-Konstantopoulos
author_facet Alyssa Grogan
Weiliang Huang
Annie Brong
Maureen A. Kane
Aikaterini Kontrogianni-Konstantopoulos
author_sort Alyssa Grogan
collection DOAJ
description IntroductionObscurin (720–870 kDa) is a giant cytoskeletal and signaling protein that possesses both structural and regulatory functions in striated muscles. Immunoglobulin domains 58/59 (Ig58/59) of obscurin bind to a diverse set of proteins that are essential for the proper structure and function of the heart, including giant titin, novex-3, and phospholamban (PLN). Importantly, the pathophysiological significance of the Ig58/59 module has been further underscored by the discovery of several mutations within Ig58/59 that are linked to various forms of myopathy in humans. We previously generated a constitutive deletion mouse model, Obscn-ΔIg58/59, that expresses obscurin lacking Ig58/59, and characterized the effects of this deletion on cardiac morphology and function through aging. Our findings demonstrated that Obscn-ΔIg58/59 male animals develop severe arrhythmia, primarily manifesting as episodes of junctional escape and spontaneous loss of regular p-waves, reminiscent of human atrial fibrillation, accompanied by significant atrial enlargement that progresses in severity with aging.Methods and ResultsTo comprehensively characterize the molecular alterations responsible for these pathologies, we performed proteomic and phospho-proteomic analyses in aging Obscn-ΔIg58/59 atria. Our studies revealed extensive and novel alterations in the expression and phosphorylation profile of major cytoskeletal proteins, Ca2+ regulators, and Z-disk associated protein complexes in the Obscn-ΔIg58/59 atria through aging.DiscussionThese studies implicate obscurin, particularly the Ig58/59 module, as an essential regulator of the Z-disk associated cytoskeleton and Ca2+ cycling in the atria and provide new molecular insights into the development of atrial fibrillation and remodeling.
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spelling doaj.art-43a7f9973aee416da0afaef2d5e76c962023-05-26T08:13:40ZengFrontiers Media S.A.Frontiers in Cardiovascular Medicine2297-055X2023-04-011010.3389/fcvm.2023.10858401085840Alterations in cytoskeletal and Ca2+ cycling regulators in atria lacking the obscurin Ig58/59 moduleAlyssa Grogan0Weiliang Huang1Annie Brong2Maureen A. Kane3Aikaterini Kontrogianni-Konstantopoulos4Department of Biochemistry and Molecular Biology, University of Maryland, Baltimore, MD, United StatesDepartment of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD, United StatesDepartment of Biochemistry and Molecular Biology, University of Maryland, Baltimore, MD, United StatesDepartment of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD, United StatesDepartment of Biochemistry and Molecular Biology, University of Maryland, Baltimore, MD, United StatesIntroductionObscurin (720–870 kDa) is a giant cytoskeletal and signaling protein that possesses both structural and regulatory functions in striated muscles. Immunoglobulin domains 58/59 (Ig58/59) of obscurin bind to a diverse set of proteins that are essential for the proper structure and function of the heart, including giant titin, novex-3, and phospholamban (PLN). Importantly, the pathophysiological significance of the Ig58/59 module has been further underscored by the discovery of several mutations within Ig58/59 that are linked to various forms of myopathy in humans. We previously generated a constitutive deletion mouse model, Obscn-ΔIg58/59, that expresses obscurin lacking Ig58/59, and characterized the effects of this deletion on cardiac morphology and function through aging. Our findings demonstrated that Obscn-ΔIg58/59 male animals develop severe arrhythmia, primarily manifesting as episodes of junctional escape and spontaneous loss of regular p-waves, reminiscent of human atrial fibrillation, accompanied by significant atrial enlargement that progresses in severity with aging.Methods and ResultsTo comprehensively characterize the molecular alterations responsible for these pathologies, we performed proteomic and phospho-proteomic analyses in aging Obscn-ΔIg58/59 atria. Our studies revealed extensive and novel alterations in the expression and phosphorylation profile of major cytoskeletal proteins, Ca2+ regulators, and Z-disk associated protein complexes in the Obscn-ΔIg58/59 atria through aging.DiscussionThese studies implicate obscurin, particularly the Ig58/59 module, as an essential regulator of the Z-disk associated cytoskeleton and Ca2+ cycling in the atria and provide new molecular insights into the development of atrial fibrillation and remodeling.https://www.frontiersin.org/articles/10.3389/fcvm.2023.1085840/fullobscurinatrial fibrillationarrhythmiaZ-diskCa2+ cyclingcytoskeleton
spellingShingle Alyssa Grogan
Weiliang Huang
Annie Brong
Maureen A. Kane
Aikaterini Kontrogianni-Konstantopoulos
Alterations in cytoskeletal and Ca2+ cycling regulators in atria lacking the obscurin Ig58/59 module
Frontiers in Cardiovascular Medicine
obscurin
atrial fibrillation
arrhythmia
Z-disk
Ca2+ cycling
cytoskeleton
title Alterations in cytoskeletal and Ca2+ cycling regulators in atria lacking the obscurin Ig58/59 module
title_full Alterations in cytoskeletal and Ca2+ cycling regulators in atria lacking the obscurin Ig58/59 module
title_fullStr Alterations in cytoskeletal and Ca2+ cycling regulators in atria lacking the obscurin Ig58/59 module
title_full_unstemmed Alterations in cytoskeletal and Ca2+ cycling regulators in atria lacking the obscurin Ig58/59 module
title_short Alterations in cytoskeletal and Ca2+ cycling regulators in atria lacking the obscurin Ig58/59 module
title_sort alterations in cytoskeletal and ca2 cycling regulators in atria lacking the obscurin ig58 59 module
topic obscurin
atrial fibrillation
arrhythmia
Z-disk
Ca2+ cycling
cytoskeleton
url https://www.frontiersin.org/articles/10.3389/fcvm.2023.1085840/full
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