Protein Phosphatase 2A Interacts with the Na+,K+-ATPase and Modulates Its Trafficking by Inhibition of Its Association with Arrestin

Background: The P-type ATPase family constitutes a collection of ion pumps that form phosphorylated intermediates during ion transport. One of the best known members of this family is the Na +,K +-ATPase. The catalytic subunit of the Na +,K +-ATPase includes several functional domains that determine its enzymatic and trafficking properties. Methodology/Principal Findings: Using the yeast two-hybrid system we found that protein phosphatase 2A (PP2A) catalytic C-subunit is a specific Na +,K +-ATPase interacting protein. PP-2A C-subunit interacted with the Na +,K +-ATPase, but not with the homologous sequences of the H +,K +-ATPase. We confirmed that the Na +,K +-ATPase interacts with a complex of A- and C-subunits in native rat kidney. Arrestins and G-protein coupled receptor kinases (GRKs) are important regulators of G-protein coupled receptor (GPCR) signaling, and they also regulate Na +,K +-ATPase trafficking through direct association. PP2A inhibits association between the Na +,K +-ATPase and arrestin, and diminishes the effect of arrestin on Na +,K +-ATPase trafficking. GRK phosphorylates the Na +,K +-ATPase and PP2A can at least partially reverse this phosphorylation. Conclusions/Significance: Taken together, these data demonstrate that the sodium pump belongs to a growing list of io

AHA/ACC vs ESC Guidelines for Management of Adults With Congenital Heart Disease JACC Guideline Comparison

The American Heart Association and American College of Cardiology published practice guidelines for the management of adult congenital heart disease in 2018 and the European Society of Cardiology published analogous guidelines in 2020. Although there are broad areas of consensus between the 2 documents, there are important differences that impact patient management. This review discusses key areas of agreement and disagreement between the 2 guidelines, with discussion of possible reasons for disagreement and potential implications. (J Am Coll Cardiol 2021;78:1904-1918) (c) 2021 by the American College of Cardiology Foundation.Cardiolog

Palladium nanoparticles and nanowires deposited electrochemically: AFM and electrochemical characterization

Abstract Palladium nanoparticles and nanowires electrochemically deposited onto a carbon surface were studied using cyclic voltammetry, impedance spectroscopy and atomic force microscopy. The ex situ and in situ atomic force microscopy (AFM) topographic images showed that nanoparticles and nanowires of palladium were preferentially electrodeposited to surface defects on the highly oriented pyrolytic graphite surface and enabled the determination of the Pd nanostructure dimensions on the order of 50–150 nm. The palladium nanoparticles and nanowires electrochemically deposited onto a glassy carbon surface behave differently with respect to the pH of the electrolyte buffer solution. In acid or mild acid solutions under applied negative potential, hydrogen can be adsorbed/absorbed onto/into the palladium lattice. By controlling the applied negative potential, different quantities of hydrogen can be incorporated, and this process was followed, analysing the oxidation peak of hydrogen. It is also shown that the growth of the Pd oxide layer begins at negative potentials with the formation of a pre-monolayer oxide film, at a potential well before the hydrogen evolution region. At positive potentials, Pd(0) nanoparticles undergo oxidation, and the formation of a mixed oxide layer was observed, which can act as nucleation points for Pd metal growth, increasing the metal electrode surface coverage. Depending on thickness and composition, this oxide layer can be reversibly reduced. AFM images confirmed that the PdO and PdO2 oxides formed on the surface may act as nucleation points for Pd metal growth, increasing the metal electrode surface coverage