Destabilization of cardiac myosin acetylation and sequestration with type 2 diabetes mellitus

Figures

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  Fig. 1. Global proteome profiling of non-T2DM and T2DM. A Protein rank plot based on Log2 intensities shows similar muscle specific detection patterns of global proteomics in both non-TD2M (N = 15) and T2DM (N = 8) samples. B Differential analyses between conditions (250-permutaiton corrected p value < 0.05, fold-change > 1) shows a down-regulation and up-regulation in protein abundances, which, when enrichment analyses for biological processing terms are performed C, reveals a coordinated set of proteins up-regulated in T2DM samples only. The network of terms was developed in ShinyGO with enriched terms being condensed into a network via REVIGO, where only networks with ≥ 3 terms are represented. The strength in colour of each node represents the Log10 FDR of significance for each term

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  Fig. 2. Dysregulated acetylation levels in myosin molecules in T2DM. A to F display the total amount of acetylation in proteins or groups of proteins in non-TD2M (N = 15) and T2DM (N = 8) samples. These are intensity values that are log2-transformed, imputed, and normalized to the global proteome. G Sites are plotted along the MYH7 sequence and annotated with motor domain, lever arm, and rod regions. H is the in-silico simulation (EvoEF) where ΔΔGStabilities were calculated for mutations chemically mimicking acetyl-lysines. The unpaired t-test was applied with p < 0.05 as level of significance

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  Fig. 3. Increased lattice spacing and preferred myosin ON state in T2DM. A represents typical X-ray diffraction patterns. B corresponds to the inter-filament lattice spacing derived from the 1.0 equatorial reflections (d1,0) whilst C displays the equatorial intensity ratio (I1,1/I1,0) and D shows the spacing for the myosin meridional reflection, M3. Dots correspond to individual cardiac strips (multiple strips were obtained from each donor, with variable numbers of strips per heart). A linear mixed-effects model was employed with p < 0.05 as level of significance. For dots corresponding to averages per patient, please see Fig. S2

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  Fig. 4. Preserved myosin biochemical SRX and DRX states with T2DM. A shows typical Mant-ATP chase experiments performed at a sarcomere length of 2.00 μm to estimate the proportions of myosin heads in the DRX (B; P1) or SRX states (C; P2). DRX (D; T1), SRX ATP turnover lifetimes (E; T2) and theoretical related myosin ATP usage (F) were also estimated from these Mant-ATP chase assays. Dots correspond to individual cardiac strips (multiple strips were isolated from each patient, with various numbers of preparations per heart). A linear mixed-effects model was employed with p < 0.05 as level of significance. For dots corresponding to averages per patient, please see Fig. S3