Aggregate-prone R120GCRYAB triggers multifaceted modifications of the thioredoxin system. Antioxid Redox Signal 2014 Jun 20;20(18):2891-906
Date
11/05/2013Pubmed ID
24180415Pubmed Central ID
PMC4039002DOI
10.1089/ars.2013.5340Scopus ID
2-s2.0-84901639700 (requires institutional sign-in at Scopus site) 9 CitationsAbstract
AIMS: The human mutation R120G in the αB-crystallin (CRYAB) causes a multisystemic disease that is characterized by hypertrophic cardiomyopathy and cytoplasmic protein aggregates. In transgenic mice, human R120GCRYAB (hR120GTg) expression in heart sequentially modifies the REDOX status, in part by the activation of the nuclear factor, erythroid derived 2, like 2 (Nrf2). Thioredoxin system (TS) components are NRF2 target genes, so it could be hypothesized that TS was affected in hR120GTg mice.
RESULTS: Transgenic hearts overexpressed thioredoxin 1 (Trx1), which was identified by isotope coded affinity tag-mass spectrometry, among hundreds of peptides displaying an increased reduced/oxidized ratio. Coupled to this higher level of reduced cysteines, the activity of thioredoxin reductase 1 (TrxR1) was augmented by 2.5-fold. Combining mutiple experimental approaches, the enzymatic regulation of TrxR1 by a histone deacetylase 3 (HDAC3)-dependent level of acetylation was confirmed. In vitro and in vivo functional tests established that TrxR1 activity is required to mitigate aggregate development, and this could be mediated by Bcl-2-associated athanogene 3 (BAG3) as a potential TS substrate.
INNOVATION AND CONCLUSIONS: This study uncovers the compartmentalized changes and the involvement of TS in the cardiac stress response elicited by misfolded proteins such as R120GCRYAB. Our work suggests that R120GCRYAB triggers a defensive pathway acting through the newly identified interacting partners HDAC3, TrxR1, and BAG3 to counter aggregate growth. Therefore, those interactors may function as modifier genes contributing to the variable onset and expressivity of such human diseases. Furthermore, our work underscores the potential organismal effects of pharmacological interventions targeting TS and HDAC.
Author List
Banerjee Mustafi S, Grose JH, Zhang H, Pratt GW, Sadoshima J, Christians ES, Benjamin IJAuthor
Ivor J. Benjamin MD Center Director, Professor in the Medicine department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
Adaptor Proteins, Signal TransducingAnimals
Apoptosis Regulatory Proteins
Cardiomyopathy, Hypertrophic
Histone Deacetylases
Humans
Isotope Labeling
Mass Spectrometry
Mice
Mice, Transgenic
Myocardium
Myocytes, Cardiac
NF-E2-Related Factor 2
Oxidation-Reduction
Protein Aggregation, Pathological
Thioredoxin Reductase 1
Thioredoxins
alpha-Crystallin B Chain
