Substrate recognition by the cell surface palmitoyl transferase DHHC5

The cardiac phosphoprotein phospholemman (PLM) regulates the cardiac sodium pump, activating the pump when phosphorylated and inhibiting it when palmitoylated. Protein palmitoylation, the reversible attachment of a 16 carbon fatty acid to a cysteine thiol, is catalyzed by the Asp-His-His-Cys (DHHC) motif-containing palmitoyl acyltransferases. The cell surface palmitoyl acyltransferase DHHC5 regulates a growing number of cellular processes, but relatively few DHHC5 substrates have been identified to date. We examined the expression of DHHC isoforms in ventricular muscle and report that DHHC5 is among the most abundantly expressed DHHCs in the heart and localizes to caveolin-enriched cell surface microdomains. DHHC5 coimmunoprecipitates with PLM in ventricular myocytes and transiently transfected cells. Overexpression and silencing experiments indicate that DHHC5 palmitoylates PLM at two juxtamembrane cysteines, C40 and C42, although C40 is the principal palmitoylation site. PLM interaction with and palmitoylation by DHHC5 is independent of the DHHC5 PSD-95/Discs-large/ZO-1 homology (PDZ) binding motif, but requires a ∼120 amino acid region of the DHHC5 intracellular C-tail immediately after the fourth transmembrane domain. PLM C42A but not PLM C40A inhibits the Na pump, indicating PLM palmitoylation at C40 but not C42 is required for PLM-mediated inhibition of pump activity. In conclusion, we demonstrate an enzyme–substrate relationship for DHHC5 and PLM and describe a means of substrate recruitment not hitherto described for this acyltransferase. We propose that PLM palmitoylation by DHHC5 promotes phospholipid interactions that inhibit the Na pump

Multiple quantum filtered ²³Na NMR in the Langendorff perfused mouse heart:Ratio of triple/double quantum filtered signals correlate with [Na]_i

AbstractWe investigate the potential of multiple quantum filtered (MQF) 23Na NMR to probe intracellular [Na]i in the Langendorff perfused mouse heart. In the presence of Tm(DOTP) shift reagent the triple quantum filtered (TQF) signal originated largely from the intracellular sodium pool with a 32±6% contribution of the total TQF signal arising from extracellular sodium, whilst the rank 2 double-quantum filtered signal (DQF), acquired with a 54.7° flip-angle pulse, originated exclusively from the extracellular sodium pool. Given the different cellular origins of the 23Na MQF signals we propose that the TQF/DQF ratio can be used as a semi-quantitative measure of [Na]i in the mouse heart. We demonstrate a good correlation of this ratio with [Na]i measured with shift reagent at baseline and under conditions of elevated [Na]i. We compare the measurements of [Na]i using both shift reagent and TQF/DQF ratio in a cohort of wild type mouse hearts and in a transgenic PLM3SA mouse expressing a non-phosphorylatable form of phospholemman, showing a modest but measurable elevation of baseline [Na]i. MQF filtered 23Na NMR is a potentially useful tool for studying normal and pathophysiological changes in [Na]i, particularly in transgenic mouse models with altered Na regulation

Особенности влияния коронного разряда на поведение электрода-струны в системах электрофильтрации

Богуславский, Л. З. Особенности влияния коронного разряда на поведение электрода-струны в системах электрофильтрации = Special features of the impact of corona discharge on string electrodes in electrofiltration systems / Л. З. Богуславский, С. В. Чущак, В. В. Куниженков // Зб. наук. пр. НУК. – Миколаїв : НУК, 2017. – № 4 (471). – С. 67–72.Анотація. Досліджено вплив коронного об’ємного розряду на поведінку електрода-струни коаксіальних циліндричних електродних систем у комплексах електрофільтраціі газових викидів. Визначено залежності амплітуди обертання струнного електрода від напруги й матеріалу дроту.Abstract. The impact of the corona space discharge on the behavior of the string electrode in the coaxial electrode systems of the gas emission electrofiltration complexes has been subject to study. The dependencies of the rotational amplitude of the string electrode on the applied voltage and the wire material are determined.Аннотация. Исследовано влияние коронного объемного разряда на поведение электрода-струны коаксиальных цилиндрических электродных систем в комплексах электрофильтрации газовых выбросов. Определены зависимости амплитуды вращения струнного электрода от подаваемого напряжения и материала проволоки

Интеллектуальная система управления импульсным высоковольтным источником питания комплекса электрофильтрации и деструкции газовых выбросов

Богуславский, Л. З. Интеллектуальная система управления импульсным высоковольтным источником питания комплекса электрофильтрации и деструкции газовых выбросов = Intelligent control system for the high-voltage pulse power source of the complex for electrofiltration and destruction of gas emissions / Л. З. Богуславский, Л. Е. Овчинникова, C. С. Козырев // Зб. наук. пр. НУК. – Миколаїв : НУК, 2017. – № 4 (471). – С. 61–66.Анотація. Розроблено інтелектуальну систему керування імпульсним джерелом живлення системи електрофільтрації, який сприяє коригуванню параметрів імпульсів відповідно до поточного складу екологічно небезпечних промислових газових викидів. Визначено інформаційні координати й канали керувальних впливів. Доведено, що алгоритм роботи інтелектуальної системи керування дає змогу генерувати високовольтні імпульси з параметрами, які забезпечують ефективну деструкцію всіх вагомих складових газових викидів у процесі обробки.Abstract. A study has been conducted with gas emissions of different impedance as an object of processing and a high-voltage pulse generator as an object of control. It allowed defining the informational coordinates and control action channels. The experimental study employing a simulated model of high-voltage equipment of the electrofiltration system became the basis for development of the set of control laws and a knowledge base for the intelligent control system. Thus, there was developed an intelligent control system for the pulse generator of the electrofiltration system. The algorithm provides adjustments of pulse parameters according to the current composition of gas burst. This allows generating high-voltage pulses which provide an efficient decomposition of major components of gas emissions.Аннотация. Разработана интеллектуальная система управления импульсным источником питания системы электрофильтрации, обеспечивающая корректировку параметров импульсов в соответствии с текущим составом экологически опасных промышленных газовых выбросов. Определены информационные координаты и каналы управляющих воздействий. Доказано, что алгоритм работы интеллектуальной системы управления дает возможность генерировать высоковольтные импульсы с параметрами, позволяющими вести эффективную деструкцию всех весомых составляющих в процессе обработки

Аналіз моделей та визначення координат вектору стану електророзрядного синтезу вуглецевих наноматеріалів

Богуславський, Л. З. Аналіз моделей та визначення координат вектору стану електророзрядного синтезу вуглецевих наноматеріалів = Determination of spring elements characteristics using shape memory effect during thermomechanical impact / Л. З. Богуславський, Л. Є. Овчиннікова, C. С. Козирєв // Зб. наук. пр. НУК. – Миколаїв : НУК, 2016. – № 1 (463). – С. 30–35.Анотація. Проведено аналіз математичних моделей синтезу алотропних форм нановуглецю з метою виявлення факторів, що впливають на результат синтезу, значення яких можуть бути прийняті в якості координат вектору стану процесу електророзрядного синтезу вуглецевих наноматеріалів як об’єкта керування. Визначено інформаційні координати та канал керуючих впливів, що дозволить побудувати модель керування процесом з метою забезпечення продуктивного режиму синтезу вуглецевих наноматеріалів.Abstract. The analysis of mathematical models of synthesis of allotropic form of nanocarbons was done. The goal of the analysis was to determine factors which influence synthesis. As a result, the coordinates of state vector were defined along with their acceptable ranges for providing a required level of synthesis productivity. The following coordinates of state vector where proposed: T – temperature, p – pressure, W – energy. The observable coordinates of electro-discharge synthesis of carbon nanomaterials are: U – voltage, I – current, P – power, f – pulse frequency. The controlling coordinate, which allows altering the electro-discharge synthesis mode, is a discharge gap length l.Аннотация. Проведен анализ математических моделей синтеза аллотропных форм наноуглерода с целью выявления факторов, влияющих на результат синтеза, значения которых могут быть приняты в качестве координат вектора состояния процесса электроразрядного синтеза углеродных наноматериалов как объекта управления. Определены информационные координаты и канал управляющих воздействий, что позволит построить модель управления процессом с целью обеспечения продуктивного режима синтеза углеродных наноматериалов

Disulfide-activated protein kinase G Iα regulates cardiac diastolic relaxation and fine-tunes the Frank-Starling response.

The Frank-Starling mechanism allows the amount of blood entering the heart from the veins to be precisely matched with the amount pumped out to the arterial circulation. As the heart fills with blood during diastole, the myocardium is stretched and oxidants are produced. Here we show that protein kinase G Iα (PKGIα) is oxidant-activated during stretch and this form of the kinase selectively phosphorylates cardiac phospholamban Ser16-a site important for diastolic relaxation. We find that hearts of Cys42Ser PKGIα knock-in (KI) mice, which are resistant to PKGIα oxidation, have diastolic dysfunction and a diminished ability to couple ventricular filling with cardiac output on a beat-to-beat basis. Intracellular calcium dynamics of ventricular myocytes isolated from KI hearts are altered in a manner consistent with impaired relaxation and contractile function. We conclude that oxidation of PKGIα during myocardial stretch is crucial for diastolic relaxation and fine-tunes the Frank-Starling response

Phospholemman Phosphorylation Regulates Vascular Tone, Blood Pressure, and Hypertension in Mice and Humans

Background: While it has long been recognized that smooth muscle Na/K ATPase (NKA) modulates vascular tone and blood pressure (BP), the role of its accessory protein phopholemman (PLM) has not been characterized. The aim of this study was to test the hypothesis that PLM phosphorylation regulates vascular tone in vitro and this mechanism plays an important role in modulation of vascular function and BP in experimental models in vivo and in man. Methods: Mouse studies: PLM knock-in mice (PLM3SA), in which PLM is rendered unphosphorylatable, were used to assess the role of PLM phosphorylation in vitro in aortic and mesenteric vessels using wire myography and membrane potential measurements. In vivo BP and regional blood flow were assessed using Doppler flow and telemetry in young (14-16 weeks) and old (57-60 weeks) wild-type (WT) and transgenic mice. Human studies: We searched human genomic databases for mutations in PLM in the region of the phosphorylation sites and performed analyses within two human data cohorts (UK Biobank and GoDARTS) to assess the impact of an identified SNP on BP. This SNP was expressed in HEK cells and its effect on PLM phosphorylation determined using Western Blotting. Results: PLM phosphorylation at Ser63 and Ser68 limited vascular constriction in response to phenylephrine. This effect was blocked by ouabain. Prevention of PLM phosphorylation in the PLM3SA mouse profoundly enhanced vascular responses to PE both in vitro and in vivo. In ageing WT mice PLM was hypophosphorylated and this correlated with the development of ageing-induced essential hypertension. In man we identified a non-synonymous coding variant, single nucleotide polymorphism rs61753924, which causes the substitution R70C in PLM. In HEK cells the R70C mutation prevented PLM phosphorylation at Ser68. This variant's rare allele is significantly associated with increased BP in middle-aged men. Conclusions: These studies demonstrate the importance of PLM phosphorylation in the regulation of vascular tone and BP and suggest a novel mechanism, and therapeutic target, for ageing-induced essential hypertension in man

Исследование объемного разряда в системах электрофильтрации газов

Исследование объемного разряда в системах электрофильтрации газов = Study of volume discharge in electrofiltration gas systems / Л. З. Богуславский, Л. Е. Овчинникова, С. В. Чущак, С. С. Козырев // Зб. наук. пр. НУК. – Миколаїв : НУК, 2016. – № 3 (465). – С. 63–69.Розглянуто питання використання об’ємного розряду для електрофільтраціі промислових газів. Проведено експериментальні дослідження процесу запалювання об’ємного розряду, досліджено вплив конструкції електродних систем і швидкості газового потоку на умови запалювання та підтримку стабільного об’ємного розряду.It addresses the use of volume discharge electrofiltration for industrial gases. The experimental study of the process volume discharge, studied the effect of the structure of the electrode systems and gas flow rate on the ignition conditions and support a stable volume discharge. For volume discharge, which occupies the entire volume of the electrode, the electrode system is necessary to use such as "brush" with a symmetrical arrangement with respect to the collecting electrodes. The ignition voltage and the intense glow of the discharge of 55–60 kV at a pulse repetition rate of between 1 and 3 kHz. Gas flow rate to 20 m / c does not affect the appearance and maintenance of a stable ignition discharge. Pulse repetition frequency should be equal flim = v / l0. This will eliminate the effect of hydrodynamic instabilities in the discharge.Рассмотрены вопросы использования объемного разряда для электрофильтрации промышленных газов. Проведены экспериментальные исследования процесса зажигания объемного разряда, исследовано влияние конструкции электродных систем и скорости газового потока на условия зажигания и поддержку стабильного объемного разряда