Down-regulation of catalase and oxidative modification of protein kinase CK2 lead to the failure of apoptosis repressor with caspase recruitment domain to inhibit cardiomyocyte hypertrophy

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Item Type:	Article
Title:	Down-regulation of catalase and oxidative modification of protein kinase CK2 lead to the failure of apoptosis repressor with caspase recruitment domain to inhibit cardiomyocyte hypertrophy
Creators Name:	Murtaza, I., Wang, H.X., Feng, X., Alenina, N., Bader, M., Prabhakar, B.S. and Li, P.F.
Abstract:	Cardiac hypertrophy is regulated by a complex interplay of pro- and anti-hypertrophic factors. Here, we report a novel anti-hypertrophic pathway composed of catalase, protein kinase CK2 (CK2) and apoptosis repressor with caspase recruitment domain (ARC). Our results showed that ARC phosphorylation levels, CK2 activity and catalase expression levels were decreased in the hearts of the angiotensinogen transgenic mice and in cardiomyocytes treated with the hypertrophic stimuli including phenylephrine, tumor necrosis factor-alpha and angiotensin II. To understand the role of ARC in hypertrophy, we observed that enforced expression of ARC could inhibit hypertrophy. Knockdown of endogenous ARC or inhibition of its phosphorylation could sensitize cardiomyocytes to undergoing hypertrophy. The phosphorylatable but not the nonphosphorylatable ARC could inhibit hypertrophy. Thus, ARC is able to inhibit hypertrophy in a phosphorylation-dependent manner. In exploring the molecular mechanism by which CK2 activity is reduced, we found that CK2 was carbonylated in angiotensinogen transgenic mice and in cardiomyocytes treated with the hypertrophic stimuli. The decrease in catalase expression led to an elevated level of reactive oxygen species. The latter oxidatively modified CK2 resulting in its carbonylation. CK2 lost its catalytic activity upon carbonylation. ARC is phosphorylated by CK2. ARC phosphorylation levels were reduced as a consequence of the decrease of CK2 activity. To understand the molecular mechanism by which ARC inhibits hypertrophy, we observed that ARC could inhibit the activation of mitochondrial permeability transition. These results suggest that catalase, CK2 and ARC constitute an anti-hypertrophic pathway in the heart.
Keywords:	Angiotensin II, Angiotensinogen, Apoptosis Regulatory Proteins, Cardiotonic Agents, Casein Kinase II, Catalase, Cell Membrane Permeability, Down-Regulation, Enzymologic Gene Expression Regulation, Hypertrophy, Heart Mitochondria, Cardiac Muscle Proteins, Cardiac Myocytes, Oxidation-Reduction, Phenylephrine, Phosphorylation, Protein Carbonylation, Post-Translational Protein Processing, Reactive Oxygen Species, Tumor Necrosis Factor-alpha, Animals, Mice
Source:	Journal of Biological Chemistry
ISSN:	0021-9258
Publisher:	American Society for Biochemistry and Molecular Biology
Volume:	283
Number:	10
Page Range:	5996-6004
Date:	7 March 2008
Official Publication:	https://doi.org/10.1074/jbc.M706466200
PubMed:	View item in PubMed

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