The cardiac acetyl-lysine proteome

• Published in: PloS one Vol. 8; no. 7; p. e67513
• Main Authors: Foster, D Brian, Liu, Ting, Rucker, Jasma, O'Meally, Robert N, Devine, Lauren R, Cole, Robert N, O'Rourke, Brian
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 02-07-2013; Public Library of Science (PLoS)
• Subjects: Acetylation; Animals; Biology; Ca2+-transporting ATPase; Calcium; Calcium-binding protein; Cardiology; Cardiomyopathy; Cardiovascular diseases; Cell Fractionation; Chains; Chromatography, Liquid; Citric Acid Cycle - genetics; Contraction; Cyclic AMP response element-binding protein; Cytosol; Development and progression; Dietary restrictions; Enzymes; Event-related potentials; Excitation-contraction coupling; Fatty acids; Fatty Acids - metabolism; Gene Expression; Genetic aspects; Glycolysis; Glycolysis - genetics; Guinea Pigs; Heart; Heart diseases; Histones; Immunoblotting; Laboratory animals; Light chains; Lysine; Lysine - metabolism; Male; Mass spectrometry; Medicine; Metabolism; Mitochondria; Mitochondria - metabolism; Molecular Motor Proteins - genetics; Molecular Motor Proteins - metabolism; Molecular Sequence Annotation; Mutation; Myocardium - cytology; Myocardium - metabolism; Myocytes, Cardiac - cytology; Myocytes, Cardiac - metabolism; Myosin; Oxidative metabolism; Oxidative Phosphorylation; Peptides; Phosphorylation; Physics; Physiological aspects; Protein Processing, Post-Translational; Proteins; Proteome - genetics; Proteome - isolation & purification; Proteome - metabolism; Proteomics; Regulators; Ryanodine receptors; Scientific imaging; Substrates; Sucrose; Tandem Mass Spectrometry; Transcription; Tricarboxylic acid cycle; United States; United States > US; Maryland; Baltimore Maryland
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0067513

In the heart, lysine acetylation has been implicated in processes ranging from transcriptional control of pathological remodeling, to cardioprotection arising from caloric restriction. Given the emerging importance of this post-translational modification, we used a proteomic approach to investigate the broader role of lysine acetylation in the heart using a guinea pig model. Briefly, hearts were fractionated into myofilament-, mitochondrial- and cytosol-enriched fractions prior to proteolysis and affinity-enrichment of acetylated peptides. LC-MS/MS analysis identified 1075 acetylated peptides, harboring 994 acetylation sites that map to 240 proteins with a global protein false discovery rate <0.8%. Mitochondrial targets account for 59% of identified proteins and 64% of sites. The majority of the acetyl-proteins are enzymes involved in fatty acid metabolism, oxidative phosphorylation or the TCA cycle. Within the cytosolic fraction, the enzymes of glycolysis, fatty acid synthesis and lipid binding are prominent. Nuclear targets included histones and the transcriptional regulators E1A(p300) and CREB binding protein. Comparison of our dataset with three previous global acetylomic studies uniquely revealed 53 lysine-acetylated proteins. Specifically, newly-identified acetyl-proteins include Ca(2+)-handling proteins, RyR2 and SERCA2, and the myofilament proteins, myosin heavy chain, myosin light chains and subunits of the Troponin complex, among others. These observations were confirmed by anti-acetyl-lysine immunoblotting. In summary, cardiac lysine acetylation may play a role in cardiac substrate selection, bioenergetic performance, and maintenance of redox balance. New sites suggest a host of potential mechanisms by which excitation-contraction coupling may also be modulated.