Identification of protein interactors is ideally suited for the functional characterization of small molecules. 3′,5′‐cAMP is an evolutionary ancient signaling metabolite largely uncharacterized in plants. To tap into the physiological roles of 3′,5′‐cAMP, we used a chemo‐proteomics approach, thermal proteome profiling (TPP), for the unbiased identification of 3′,5′‐cAMP protein targets. TPP measures shifts in the protein thermal stability upon ligand binding. Comprehensive proteomics analysis yielded a list of 51 proteins significantly altered in their thermal stability upon incubation with 3′,5′‐cAMP. The list contained metabolic enzymes, ribosomal subunits, translation initiation factors, and proteins associated with the regulation of plant growth such as CELL DIVISION CYCLE 48. To functionally validate obtained results, we focused on the role of 3′,5′‐cAMP in regulating the actin cytoskeleton suggested by the presence of actin among the 51 identified proteins. 3′,5′‐cAMP supplementation affected actin organization by inducing actin‐bundling. Consistent with these results, the increase in 3′,5′‐cAMP levels, obtained either by feeding or by chemical modulation of 3′,5′‐cAMP metabolism, was sufficient to partially rescue the short hypocotyl phenotype of the
Heavy Flavor Wilson Coefficients in Deep-Inelastic Scattering: Recent Results
We present recent analytic results for the 3-loop corrections to the massive operator matrix element $A^{(3)}_{Qg}$ for further color factors. These results have been obtained using the method of arbitrarily large moments. We also give an overview on the results which were obtained solving all difference and differential equations for the corresponding master integrals that factorize at first order.
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- Award ID(s):
- 1719863
- NSF-PAR ID:
- 10063376
- Date Published:
- Journal Name:
- Proceedings of QCD Evolution 2017
- Volume:
- PoS(QCDEV2017)
- Page Range / eLocation ID:
- 031
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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SUMMARY actin2 actin7 mutant, severely compromised in actin level. The observed rescue was specific to 3′,5′‐cAMP, as demonstrated using a positional isomer 2′,3′‐cAMP, and true for the nanomolar 3′,5′‐cAMP concentrations reported for plant cells.In vitro characterization of the 3′,5′‐cAMP–actin pairing argues against a direct interaction between actin and 3′,5′‐cAMP. Alternative mechanisms by which 3′,5′‐cAMP would affect actin dynamics, such as by interfering with calcium signaling, are discussed. In summary, our work provides a specific resource, 3′,5′‐cAMP interactome, as well as functional insight into 3′,5′‐cAMP‐mediated regulation in plants. -
Introduction The mechanical vulnerability of the atherosclerotic cap is a crucial risk factor in asymptomatic fibroatheromas. Our research group demonstrated using numerical modeling that microcalcifications (µCalcs) located in the fibrous cap can multiply the tissue background stress by a factor 2-7[1-3]. We showed how this effect depends on the size and the ratio of the gap between particles pairs (h) and their diameter (D) along the tensile axis. In this context, we studied the impact of micro-beads of varying diameters and concentration on the rupture of human fibroatheroma laboratory models. Methods We created silicone-based (DowsilEE-3200, Dow Corning) dumbbell-shaped models (80%-scaled ASTM D412-C) of arterial tissues. Samples were divided into three groups: (1) without μBeads (control, n=12), (2) with μBeads of varying diameter (D=30,50,100μm) at a constant concentration of 1% weight (n=36), (3) with μBeads of constant diameter (D=50μm) at different concentrations (3% and 5% weight) (n=24). Before testing, samples were scanned under Micro-CT, at a resolution of 4µm. Images were then reconstructed in NRecon (SkySCan, v.2014) and structural parameters obtained in CTan (SkyScan, v.2014). These data were used to calculate the number of beads and their respective h/D ratio in a custom-made MATLAB script. We tested the samples using a custom-made micro material testing system equipped with real-time control and acquisition software (LabVIEW, v. 2018, NI). The reaction force and displacement were measured by the system and images of the sample were recorded by a high-resolution camera. The true stress and strain profiles of each sample were obtained by means of Digital Image Correlation (DIC). Results Samples with and without μBeads exhibited a distinct hyperelastic behaviour typical of arterial tissues (Fig1). Comparison of the mean ultimate stress (UTS) between groups was performed by one-way ANOVA test followed by post-hoc pairwise comparison. Regardless of the group, the presence of μBeads determined a statistically significant reduction in UTS (Fig2). Increasing the μBeads concentration was also positively correlated with lower stresses at rupture as more clusters formed resulting in lower values of h/D (Table1). Discussions Our results clearly capture the influence of μBeads on the rupture threshold of a vascular tissue mimicking material. In fact, samples with μBeads exhibit levels of UTS that are around two times lower than the control group. This effect appears to be dependent on the μBeads proximity, as lower h/D correlates with higher UTS reductions. On the other hand, the effect of particle size is not apparent for the diameters considered in this study. The plausible explanation for the observed change in rupture threshold is the increase in stress concentration around spherical μBeads, which we have previously shown in analytical and numerical studies [1-3]. Our experimental observations support our previous studies suggesting that μCalcs located within the fibroatheroma cap may be responsible for significantly increasing the risk of cap rupture that precedes myocardial infarction and sudden death.more » « less
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.22323/1.308.0031
