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Connexin hemichannels were identified as the first members of the eukaryotic large-pore channel family that mediate permeation of both atomic ions and small molecules between the intracellular and extracellular environments. The conventional view is that their pore is a large passive conduit through which both ions and molecules diffuse in a similar manner. In stark contrast to this notion, we demonstrate that the permeation of ions and of molecules in connexin hemichannels can be uncoupled and differentially regulated. We find that human connexin mutations that produce pathologies and were previously thought to be loss-of-function mutations due to the lack of ionic currents are still capable of mediating the passive transport of molecules with kinetics close to those of wild-type channels. This molecular transport displays saturability in the micromolar range, selectivity, and competitive inhibition, properties that are tuned by specific interactions between the permeating molecules and the N-terminal domain that lies within the pore-a general feature of large-pore channels. We propose that connexin hemichannels and, likely, other large-pore channels, are hybrid channel/transporter-like proteins that might switch between these two modes to promote selective ion conduction or autocrine/paracrine molecular signaling in health and disease processes.

As an abiotic stress factor, salinity significantly affects the physiological activities of crustaceans. In this study, transcriptome sequencing was used to evaluate the mechanism of ion transport and the physiological response of black tiger shrimp (Penaeus monodon) under low salt stress. Four hundred post larval (PL) stage P. monodon were distributed in eight experimental tanks and exposed to 3 or 5 ppt salt concentrations for 96 h. Low salinity significantly reduced the survival rate of shrimp but simultaneously activated the activity of ion transporter enzymes Na+/K+-ATPase (NKA) and Ca2+/Mg2+-ATPase), the expression of NKA, galectin 10, and cytochrompe c peroxidase genes, and the activity and expression of antioxidant-related genes (superoxide dismutase, catalase, heat shock protein 60). Low salt stress activated the urea cycle but significantly inhibited glutathione metabolization-related indicators (glutamate dehydrogenase, glutaminase, glutamic acid). RNA-seq analysis identified 221 differentially expressed genes (78 up-regulated and 143 down-regulated). Quantitative real-time PCR and RNA-seq results of 11 of them were consistent, illustrating the validity of the transcriptomic predictions. Gene set enrichment analysis results showed that calcium ion transmembrane transport, calmodulin binding, the stress-activated protein kinase signaling cascade, and regulation of the cytosolic calcium ion concentration process were significantly enriched. These results showed that low salt stress activated the calcium-dominated ion transport pathway and promoted molting growth of P. monodon. They also indicate that there is potential for larval rearing shrimp under low salt conditions. [ABSTRACT FROM AUTHOR]

β-MnO2, as the most stable phase of polycrystalline MnO2, has a narrow tunnel structure that limits ion diffusion and electron transfer, restricting its application in supercapacitors. In this work, we present a novel all-in-one MnO2-based material, β-MnO2@δ-MnO2, featuring a unique three-dimensional architecture with ultrathin δ-MnO2 nanostructures vertically grown on the β-MnO2 network. This innovative design leverages the structural support of β-MnO2 to enhance the electrode material's specific surface area and effectively mitigate volume changes during ion adsorption/desorption, a key factor for improving cycling stability. As a result, the β-MnO2@δ-MnO2 composite demonstrates exceptional electrochemical performance, with a remarkable cycling stability of 98% capacitance retention after 10,000 cycles. Additionally, it maintains 74.2% of its capacitance when the current density increases from 1.0 to 20 A g–1, showcasing an outstanding rate capability. When assembled into an asymmetric supercapacitor device, the β-MnO2@δ-MnO2 electrodes deliver a high surface capacitance of 287.3 mF cm–2 and a significant area energy density of 159.3 μWh cm–2. This work represents a significant advancement in the optimization of β-MnO2 for supercapacitor applications, demonstrating the practical benefits of rational nanostructure design. The β-MnO2@δ-MnO2 composite not only enhances performance in energy storage devices but also holds potential for other applications, offering new opportunities for the development of flexible, high-performance energy storage systems. [ABSTRACT FROM AUTHOR]

Chloroplasts play a pivotal role in the metabolism of leaf mesophyll cells, functioning as a cellular hub that orchestrates molecular reactions in response to environmental stimuli. These organelles contain complex protein machinery for energy conversion and are indispensable for essential metabolic pathways. Proteins located within the chloroplast envelope membranes facilitate bidirectional communication with the cell and connect essential pathways, thereby influencing acclimation processes to challenging environmental conditions such as temperature fluctuations and light intensity changes. Despite their importance, a comprehensive overview of the impact of envelope-located proteins during acclimation to environmental changes is lacking. Understanding the role of these proteins in acclimation processes could provide insights into enhancing stress tolerance under increasingly challenging environments. This review highlights the significance of envelope-located proteins in plant acclimation. [ABSTRACT FROM AUTHOR]

The ionic conductance in a charged nanopore exhibits a power-law behavior in low salinity—as has been verified in many experiments ( G 0 ∝ c 0 α )—which is governed by surface charges. The surface charge inside a nanopore determines the zeta potential and ion distributions, which have a significant impact on ion transport, especially in a single-digit nanopore with potential leakage. However, precisely measuring surface charge density in a single-digit nanopore remains a challenge. Here, we propose a methodology for exploring the power-law variation of ionic conductance, with potential leakage taken into account. We conducted experiments to measure the ionic current using silicon nitride nanopores and employed a continuous theory to explore the relationship between pore-bound concentration and surface charges. Considering that the influence of potential leakage on concentration follows a power-law relationship, we established a coefficient ( α ) to examine the controlling factors of potential leakage and modified the conductance model to obtain the ion mobility inside a nanopore. [ABSTRACT FROM AUTHOR]

Solid-state lithium battery (SSLB) is considered as one of the promising candidates for next-generation power batteries due to high safety, unprecedented energy density and favorable adaptability to high pression and temperature. However, the system of solid electrolyte (SE), as one of the most important components in SSLB, is usually plagued by clumsy ionic transport, leading to poor rate performance of the SSLBs. Herein, a unique perspective is proposed to re-examine the ion-transport behavior in lithium conductors by tracing Liþ at multiscale, including microscopic, mesoscopic and macroscopic scales. The multi-scale ion-transport mechanisms and corresponding characterization techniques are analyzed in depth. Furthermore, some strategies of structure design to improve ion-transport kinetics at corresponding scales are elaborated systematically, involving the modulation of microscopic homogeneous structure, mesoscopic heterogeneous structure and macroscopic structures, etc. The proposed generalized rules for SEs are expected to construct a close link from mechanism-structure-characterization to high performances for SSLBs. [ABSTRACT FROM AUTHOR]

The Na, K–ATPase generates an asymmetric ion gradient that supports multiple cellular functions, including the control of cellular volume, neuronal excitability, secondary ionic transport, and the movement of molecules like amino acids and glucose. The intracellular and extracellular levels of Na+ and K+ ions are the classical local regulators of the enzyme's activity. Additionally, the regulation of Na, K–ATPase is a complex process that occurs at multiple levels, encompassing its total cellular content, subcellular distribution, and intrinsic activity. In this context, the enzyme serves as a regulatory target for hormones, either through direct actions or via signaling cascades triggered by hormone receptors. Notably, FXYDs small transmembrane proteins regulators of Na, K–ATPase serve as intermediaries linking hormonal signaling to enzymatic regulation at various levels. Specifically, members of the FXYD family, particularly FXYD1 and FXYD2, are that undergo phosphorylation by kinases activated through hormone receptor signaling, which subsequently influences their modulation of Na, K–ATPase activity. This review describes the effects of FXYD2, cardiotonic steroid signaling, and hormones such as angiotensin II, dopamine, insulin, and catecholamines on the regulation of Na, K–ATPase. Furthermore, this review highlights the implications of Na, K–ATPase in diseases such as hypertension, renal hypomagnesemia, and cancer. [ABSTRACT FROM AUTHOR]

The World Health Organization has described the antimicrobial resistance crisis as one of the top ten global public health threats. New antimicrobial agents that can fight infections caused by antimicrobial resistant pathogens are therefore needed. A potential strategy is the development of small molecules that can selectively interact with bacterial membranes (or membranes of other microbial pathogens), and thereby rapidly kill the bacteria. Here, we report the structure‐activity relationship within a group of 22 compounds that were designed to bind the bacterial lipid phosphatidylethanolamine (PE). Liposome‐based studies reveal that the lipophilicity of the compounds has the strongest effect on both the affinity and selectivity for PE. The best results were obtained for compounds with logP≈3.75, which showed a 5x–7x selectivity for bacterial PE lipids over human PC (phosphatidylcholine) lipids. Furthermore, these compounds also showed potent antibacterial activity against the Gram‐positive bacterium B. cereus, with minimum inhibitory concentrations (MICs) below 10 μM, a concentration where they showed minimal hemolytic activity against human red blood cells. These results not only show the possibility of PE‐binding small molecules to function as antibiotics, but also provide guidelines for the development of compounds targeting other types of biologically relevant membrane lipids. [ABSTRACT FROM AUTHOR]

Manganese dioxide materials exhibit an unstable crystal structure due to the Jahn–Teller effect and the disproportionation reaction of Mn3+ to Mn2+/Mn4+. Therefore, how to regulate and control the electronic state of Mn in MnO2 materials and achieve higher structural stability constitutes the cornerstone for large-scale applications. Ferrous iron possesses strong reducibility, while manganese dioxide has oxidation properties, and both undergo redox reactions. During the reaction process, some electrons acquired by manganese ions are reduced, and their average valence state decreases, which leads to a change in the chemical bonds between manganese ions and oxygen ions, resulting in oxygen ions being more readily separated from the crystal lattice and thus forming oxygen vacancies. In this paper, through a hydrothermal reaction, the average valence state of manganese is lowered, the proportion of Mn3+ is increased, and the exposed proportion of adsorbed oxygen is enhanced by the reaction of ferrous iron with potassium permanganate, subsequently constructing nanorod manganese dioxide rich in oxygen vacancies. When utilized as cathodes of aqueous zinc-ion batteries, it offers a specific capacity as high as 192.24 mAh g–1 at 2 A g–1 and retains 172 mAh g–1 after 1000 cycles at 1 A g–1. This indicates that a more stable structure can restrain the structural damage caused by the cyclic intercalation/extraction of H+ and Zn2+, and more oxygen vacancies can promote electrode reaction kinetics. Moreover, the assembly of the soft-pack battery demonstrates its flexible performance, which paves the way for the large-scale energy storage production and application of zinc-ion batteries. [ABSTRACT FROM AUTHOR]

Zinc (Zn) metal batteries could be the technology of choice for sustainable battery chemistries owing to its better safety and cost advantage. However, their cycle life and Coulombic efficiency (CE) are strongly limited by the dendritic growth and side reactions of Zn anodes. Herein, we proposed an in situ construction of a metal‐phosphonate‐organic network (MPON) with three‐dimensional interconnected networks on Zn metal, which can act as an ion enrichment layer for Zn anodes in Zn‐metal batteries. This MPON with abundant porous structure and phosphate sites possesses ion enriching properties and high Zn2+ transference number (0.83), which is beneficial for enhancing Zn2+ migration and self‐concentrating kinetics. Meanwhile, MPON offers hydrophobicity to effectively inhibit the water‐induced Zn anode corrosion. As a result, the Zn electrode exhibits superior Zn/Zn2+ reversibility of over 4 months at 3 mA cm−2 and a high CE of 99.6 %. Moreover, the Zn/NaV3O8 ⋅ 1.5H2O and Zn/MnO2 full cells using ultrathin Zn anodes (10 μm) exhibit high‐capacity retention of 81 % and 78 % after 1400 and 1000 cycles, respectively. This work provides a unique promise to design high‐performance anode for practical Zn‐metal‐based batteries. [ABSTRACT FROM AUTHOR]

Efficient OH− conduction in anion exchange membranes (AEMs) is pivotal for the advancement and industrialization of sustainable electrochemical technologies in alkaline environments, including water electrolysis, fuel cells, and CO2 electroreduction. We here designed AEMs with a novel class of rigid heteroatom‐free micropores (HFMs), engineered at the molecular level to facilitate rapid ionic transport in an ultra‐stable manner. By manipulating monomers, our design strategically controls the torsional angles and energy barriers within the polymeric backbones, creating sub‐nanometer ionic channels that precisely regulate porosity. These hydrophilic micropores significantly enhance the mobility of OH−/H2O, achieving over a 150 % increase in self‐diffusion coefficient compared to commercial AEMs and elevating OH− conductivity to a leading 215 mS cm−1 at 80 °C. Moreover, the robust carbon‐carbon bond construction in HFMs offers the stability that is four orders of magnitude higher under severe alkaline conditions compared to existing wisdoms, with a demonstrated operational lifespan of over 4000 hours. The integration of HFM‐AEMs into water electrolyzers not only supports the use of platinum group metal‐free catalysts but also exhibits exceptional energy efficiency and extended durability, highlighting their substantial potential for wide‐ranging applications in emerging electrochemical technologies. [ABSTRACT FROM AUTHOR]

Summary Cellular membranes primarily consist of proteins and lipids. These proteins perform cellular functions such as metabolic regulation, environmental and hormonal signal sensing, and nutrient transport. There is increasing experimental evidence that certain lipids, particularly anionic phospholipids, can act as signaling molecules. Specific examples of functional regulation by anionic phospholipids in plant cells have been reported for transporters, channels, and even receptors. By regulating the structure and activity of membrane‐integral proteins, these phospholipids mediate the transport of phytohormones and ions, and elicit physiological responses to developmental and environmental cues. Phospholipids also control membrane protein abundance and lipid composition and abundance by facilitating vesicular trafficking. In this review, we discuss recent research that elucidates the mechanisms by which membrane‐integral transporters and channels are controlled via phospholipid signaling, as well as the regulation of membrane protein accumulation by phospholipids through coordinated removal, recycling, and degradation processes. [ABSTRACT FROM AUTHOR]

The hard carbon (HC) anodes with desirable electrochemical performances including high initial Coulombic efficiency, superior rate performance and long‐term cycling play an indispensable role in the practical application of sodium ion batteries (SIBs), which are closely related to the electrolytes them matched. Fully analyzing the mechanism of electrolyte engineering for HC anodes is crucial for promoting the commercialization of SIBs, but is still lacking. In this review, the correlation between physicochemical properties of the electrolyte and the electrochemical performance of HC is first summarized. And point out the crucial role of electrolyte properties, including ion conductivity, de‐solvation energy, and interface passivation ability for the Na+ storage in HC. Then, the formation process, composition, as well as structure of solid electrolyte interphase (SEI) on HC surface are mainly discussed, and the structure‐activity relationship of SEI is analyzed in depth. Moreover, based on the mechanism analysis, relevant electrolyte design strategies have been summarized. Finally, the challenges and future development directions of the electrolyte engineering of HC are proposed. This review is expected to provide professional theoretical guidance for the development of electrolyte and contribute to the rational design of high‐performance HC anodes, promoting the industrialization of SIBs. [ABSTRACT FROM AUTHOR]

Pyrethroids are pesticides used in agriculture, the textile industry, wood processing, and human and animal medicine. Pyrethroids inhibit voltage-sensitive sodium channels (VSSCs) in insects and mammals. It results in the premature opening and/or delayed closing of the channels, causing a prolonged influx of Na+ ions into the cell. Insects absorb pyrethroids throughout the entire body surface, while poisoning in humans most often occurs by inhalation and through the skin. In this study, 52 fragments of human skin taken from the eyelid fold were examined. A modified Ussing chamber was used to measure the active ion transport in epithelial tissue and quantify the tissue viability and integrity. Both permethrin and deltamethrin solutions induced changes in the transport of ions, mainly sodium, but by different mechanisms. Permethrin affected the transepithelial transport of sodium ions in a long-term mechanism, while deltamethrin affected the ability to respond to stimuli in an immediate mechanism. Contact with deltamethrin may cause a delay/slowness of sensation, inflammation, hypersensitivity, and/or allergy. The action of permethrin takes place in the intercellular spaces and is associated with the possibility of faster decomposition/metabolism, while deltamethrin interacts with receptors, channels, and the cell membrane, which translates into slower decomposition and longer action in the tissue. [ABSTRACT FROM AUTHOR]

Zinc is an important regulator of various biological processes such as protein synthesis, cell proliferation, migration and autophagy. The zinc transporter ZIP13 (SLC39A13) is a homodimeric metal transporter functioning in transport of zinc, iron, and calcium plasma in body. ZIP13 is involved in disease by regulating zinc homeostasis, such as the key role of ZIP13 in connective tissue development because it is involved in the BMP/TGF-β signaling pathway. ZIP13 promotes the metastasis of human ovarian cancer cells by activating the Src/FAK signaling pathway and ZIP13 inhibits the biogenesis and energy expenditure of beige adipocytes by regulating C/EBP-β expression. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) nanofluidic channels are emerging as potential candidates for harnessing osmotic energy from salinity gradients. However, conventional 2D nanofluidic membranes suffer from high transport resistance and low ion selectivity, leading to inefficient transport dynamics and limiting energy conversion performance. In this study, we present a novel composite membrane consisting of porous MXene (PMXene) nanosheets featuring etched nanopores, in conjunction with cellulose nanofibers (CNF), yielding enhancement in ion flux and ion selectivity. A mild H2O2 oxidant is employed to etch and perforate the MXene sheets to create a robust network of cation transportation nanochannels that effectively reduces the energy barrier for cation transport. Additionally, CNF with a unique nanosize and high charge density further enhances the charge density and mechanical stability of the nanofluidic system. Under neutral pH and room temperature, the PMXene/CNF membrane demonstrates a maximum output power density of 0.95 W·m−2 at a 50-fold KCl gradient. Notably, this represents a 43% improvement over the performance of the pristine MXene/CNF membrane. Moreover, 36 nanofluidic devices connected in series are demonstrated to achieve a stable voltage output of 5.27 V and power a calculator successfully. This work holds great promise for achieving sustainable energy harvesting with efficient osmotic energy conversion utilization. [ABSTRACT FROM AUTHOR]

The crustacean molting cycle is triggered by the elevation of ecdysteroid levels in the hemolymph during late pre‐molt. It is known that these animals absorb water through the intestine and gills to promote bodily swelling and rupture of the old exoskeleton. The participation of two membrane proteins responsible for the most uptake of water during the late pre‐molt has been shown in the gill and gut cells of the freshwater shrimp Palaemon argentinus: Na+/K+‐ATPase (NKA), which generates an osmoionic gradient, and Aquaporins (AQPs), water channels, which provide higher water permeability. Studies investigating the action of ecdysteroids on these proteins are scarce. Therefore, we investigated 20‐hydroxyecdisone (20E) in relation to the regulation of NKA and AQPs in the gill and gut cells of P. argentinus. We exposed primary cultures of both gut and gill cells to 20E. Gill cells treated with hormone in the presence of NKA‐blockers, exhibited a reduction in volume, and cells treated with 20E showed a greater expression of NKA than untreated cells. Additionally, gills cells treated with 20E showed an increase in volume (∼60%), which the aquaporin inhibitor (HgCl2) prevented. The participation of AQPs in the influx of water was corroborated by a greater expression of AQP in cells treated with 20E compared to untreated cells. Gut cells of animals in intermolt exposed to hormone (20E) maintained their initial cell volume. With the addition of HgCl2, these cells showed a reduction in volume similar to cells of animals in pre‐molt. Immunocytochemistry showed a high expression of AQP in gut cells treated with 20E. These findings suggest that 20E regulates the expression of AQP and NKA in the late pre‐molt, to provide water uptake for molting. This work offers new perspectives concerning the molting hormone, placing it as a crucial part of water uptake for ecdysis. [ABSTRACT FROM AUTHOR]

The beneficial effects of endophytes on plant growth, development and yield are well known. Modulating plant growth-promoting substances and ameliorating biotic and abiotic stresses are some of the key mechanisms that are deployed by endophytes to facilitate host growth and defence. However, the understanding of the plant's genome response to their presence is still limited. Therefore, this study provides an insight into the microbiome of B. juncea seeds as well as leaves, and its impact on plant growth and development. It also correlates their presence with the changes in plant. Removal of seed-borne culturable endophytes resulted in trade-off of accelerated growth with decreased biomass. 16S metagenomics revealed that bacterial endophyte diversity and density varied with stage of the plant. We found that 22 endophytic genera including Enterococcus, Halobacteroides, Planktothrix and Streptomyces were observed irrespective of Bavistin treatment and age of the plant. Removal of culturable endophytes also led to downregulation of crucial genes involved in growth, photosynthesis (Photosystem I assembly protein, Photosystem II reaction center protein and Rubisco), transport (nitrate transporter; NRT) and regulation of plant hormones (auxin homeostasis and signalling; CYP83A1) in B. juncea. To the best of our knowledge, this is the first report of the response of plant' transcriptome to changes in endophyte composition indicating a strong possibility of host gene regulation by the endophytic partner. The exact mechanism of the same needs to be further explored. [ABSTRACT FROM AUTHOR]