AT1 Receptor Induced Alterations in Histone H2A Reveal Novel Insights into GPCR Control of Chromatin Remodeling

Chronic activation of angiotensin II (AngII) type 1 receptor (AT1R), a prototypical G protein-coupled receptor (GPCR) induces gene regulatory stress which is responsible for phenotypic modulation of target cells. The AT1R-selective drugs reverse the gene regulatory stress in various cardiovascular diseases. However, the molecular mechanisms are not clear. We speculate that activation states of AT1R modify the composition of histone isoforms and post-translational modifications (PTM), thereby alter the structure-function dynamics of chromatin. We combined total histone isolation, FPLC separation, and mass spectrometry techniques to analyze histone H2A in HEK293 cells with and without AT1R activation. We have identified eight isoforms: H2AA, H2AG, H2AM, H2AO, H2AQ, Q96QV6, H2AC and H2AL. The isoforms, H2AA, H2AC and H2AQ were methylated and H2AC was phosphorylated. The relative abundance of specific H2A isoforms and PTMs were further analyzed in relationship to the activation states of AT1R by immunochemical studies. Within 2 hr, the isoforms, H2AA/O exchanged with H2AM. The monomethylated H2AC increased rapidly and the phosphorylated H2AC decreased, thus suggesting that enhanced H2AC methylation is coupled to Ser1p dephosphorylation. We show that H2A125Kme1 promotes interaction with the heterochromatin associated protein, HP1α. These specific changes in H2A are reversed by treatment with the AT1R specific inhibitor losartan. Our analysis provides a first step towards an awareness of histone code regulation by GPCRs

Wireless Charging: Its types, Standards and Applications

An electrical gadget can be powered without cords by providing electrical via an air pocket to the device in order to re-charge its capacity. The performance and practicality of cordless charging tech have noticeably enhanced lately. The introduction to cordless charging in this paper covers its basics. The evaluation of standards, which includes Qi and the A4WP, is then given, as well as a focus on their communications channels. Next, we put out a cutting-edge idea for cordless charger networking, which enables chargers to be linked for easier data gathering and management. We explain how the wireless charger network can be used to assign users to chargers, which demonstrates the usefulness in terms of a reduction costs for users to find the best chargers to recharge their mobile devices

Is Now A Good Time? An Empirical Study of Vehicle-Driver Communication Timing

CHI 2019, May 4–9, 2019, Glasgow, Scotland UKThe article of record as published may be found at https://doi.org/10.1145/3290605.3300867Advances in automotive sensing systems and speech interfaces provide new opportunities for smarter driving assistants or infotainment systems. For both safety and consumer satisfaction reasons, any new system which interacts with drivers must do so at appropriate times. We asked 63 drivers, ”Is now a good time?” to receive non-driving information during a 50-minute drive. We analyzed 2,734 responses and synchronized automotive and video data, and show that while the chances of choosing a good time can be determined with better success using easily accessible automotive data, certain nuances in the problem require a richer understanding of the driver and environment states in order to achieve higher performance. We illustrate several of these nuances with quantitative and qualitative analyses to contribute to the understanding of how to design a system that might simultaneously minimize the risk of interacting at a bad time while maximizing the window of allowable interruption.The Toyota Research Institute (TRI) provided funds to assist with this researc

Interaction of G-Protein beta gamma Complex with Chromatin Modulates GPCR-Dependent Gene Regulation

Heterotrimeric G-protein signal transduction initiated by G-protein-coupled receptors (GPCRs) in the plasma membrane is thought to propagate through protein-protein interactions of subunits, G alpha and G beta gamma in the cytosol. In this study, we show novel nuclear functions of G beta gamma through demonstrating interaction of G beta(2) with integral components of chromatin and effects of G beta(2) depletion on global gene expression. Agonist activation of several GPCRs including the angiotensin II type 1 receptor specifically augmented G beta(2) levels in the nucleus and G beta(2) interacted with specific nucleosome core histones and transcriptional modulators. Depletion of G beta(2) repressed the basal and angiotensin II-dependent transcriptional activities of myocyte enhancer factor 2. G beta(2) interacted with a sequence motif that was present in several transcription factors, whose genome-wide binding accounted for the G beta(2)-dependent regulation of approximately 2% genes. These findings suggest a wide-ranging mechanism by which direct interaction of G beta gamma with specific chromatin bound transcription factors regulates functional gene networks in response to GPCR activation in cells

Time course analysis of ligand-dependent exchange of H2AA/O and H2AM isoforms.

<p>The H2A isoforms were immunoblotted using isoforms-specific antibodies, H2AA/O and H2AM/H2A 25P hydroxyl after treatment of HEK-AT₁R with AngII (1µM) or losartan (1µM). Each data point shown represents mean ± SEM of 3–5 independent experiments. Significance values shown are for comparison between 0 and 4 hr time points, obtained by one-way ANOVA followed by unpaired Student <i>t</i>-test. <i>P</i>-values less than 0.05 are considered statistically significant.</p

Experimental flow chart.

<p>Experimental flow chart.</p

Isoform and PTM combinations observed in the H2A peaks from HEK cell lines.

<p>Isoforms and PTMs observed in the H2A peaks from HEK cell lines. First and second histone H2A FPLC peaks were subjected to mass spectrometry analysis. Each row in the table represents a discrete H2A polypeptide species assigned based on the mass. Assignment was done by comparing measured masses to calculated molecular weights of histone isoforms based on primary sequences taken from the NCBI database and allowing for modifications. Column one is the assignment of H2A isoforms and modifications, column two contains m/z for each isoform and modification at 13+ charge state, columns three and four contain deconvoluted and calculated mass (from NCBI database) respectively; Δm, difference in mass between calculated and deconvoluted mass (Da). The last three columns contain the relative abundance (%) of the isoforms and their post translational modifications (p<0.05 in 3–5 determinations). The relative abundance is taken directly from Mass Scans.</p><p>*Mass values based on NCBI database.</p

Model for modulation of H2A histone index in AT₁R signaling.

<p>The bar graph summarizes the H2A index deduced in this study. The scheme shows reversible changes in the histone code influenced by activation states of the GPCR, AT₁R.</p