Lysine acetylation regulates many eukaryotic cellular processes, but its function in prokaryotes is largely unknown. We demonstrated that central metabolism enzymes in Salmonella were acetylated extensively and differentially in response to different carbon sources, concomitantly with changes in cell growth and metabolic flux. The relative activities of key enzymes controlling the direction of glycolysis versus gluconeogenesis and the branching between citrate cycle and glyoxylate bypass were all regulated by acetylation. This modulation is mainly controlled by a pair of lysine acetyltransferase and deacetylase, whose expressions are coordinated with growth status. Reversible acetylation of metabolic enzymes ensure that cells respond environmental changes via promptly sensing cellular energy status and flexibly altering reaction rates or directions. It represents a metabolic regulatory mechanism conserved from bacteria to mammals.

Owing to the energy crisis and environmental pollution, developing efficient and robust electrochemical energy storage (or conversion) systems is urgently needed but still very challenging. Next-generation electrochemical energy storage and conversion devices, mainly including fuel cells, metal-air batteries, metal-sulfur batteries, and metal-ion batteries, have been viewed as promising candidates for future large-scale energy applications. All these systems are operated through one type of chemical conversion mechanism, which is currently limited by poor reaction kinetics. Single atom catalysts (SACs) perform maximum atom efficiency and well-defined active sites. They have been employed as electrode components to enhance the redox kinetics and adjust the interactions at the reaction interface, boosting device performance. In this Review, we briefly summarize the related background knowledge, motivation and working principle toward nextgeneration electrochemical energy storage (or conversion) devices, including fuel cells, Zn-air batteries, Al-air batteries, Li-air batteries, Li-CO 2 batteries, Li-S batteries, and Na-S batteries. While pointing out the remaining challenges in each system, we clarify the importance of SACs to solve these development bottlenecks. Then, we further explore the working principle and current progress of SACs in various device systems. Finally, future opportunities and perspectives of SACs in next-generation electrochemical energy storage and conversion devices are discussed.

The innate immune sensor NLRP3 assembles an inflammasome complex with NEK7 and ASC to activate caspase-1 and drive the maturation of proinflammatory cytokines IL-1b and IL-18. NLRP3 inflammasome activity must be tightly controlled, as its overactivation is involved in the pathogenesis of inflammatory diseases. Here, we show that NLRP3 inflammasome activation is suppressed by a centrosomal protein Spata2. Spata2 deficiency enhances NLRP3 inflammasome activity both in the macrophages and in an animal model of peritonitis. Mechanistically, Spata2 recruits the deubiquitinase CYLD to the centrosome for deubiquitination of polo-like kinase 4 (PLK4), the master regulator of centrosome duplication. Deubiquitination of PLK4 facilitates its binding to and phosphorylation of NEK7 at Ser204. NEK7 phosphorylation in turn attenuates NEK7 and NLRP3 interaction, which is required for NLRP3 inflammasome activation. Pharmacological or shRNA-mediated inhibition of PLK4, or mutation of the NEK7 Ser204 phosphorylation site, augments NEK7 interaction with NLRP3 and causes increased NLRP3 inflammasome activation. Our study unravels a novel centrosomal regulatory pathway of inflammasome activation and may provide new therapeutic targets for the treatment of NLRP3-associated inflammatory diseases.

A bifunctional self-supported electrode for water splitting to achieve a dynamic balance between HER and OER constructed via a one-step direct thermal sulfidization of NF.

Freezing is one of the most widespread used preservation methods for meats including fish meat. Traditional freezing methods such as air blast freezing and cryogenic freezing could induce some quality deterioration such as damage to cell structure, increased drip loss, and poor sensory value. Therefore, novel freezing methods have been developed to minimize the disadvantages of traditional freezing methods. This review describes the enhancement of quality attributes of muscle tissues frozen by novel freezing technologies, including high pressure freezing, electrically and magnetically assisted freezing, ultrasound assisted freezing and antifreeze protein. These quality attributes include microstructure, moisture loss, color, tenderness, protein denaturation, lipid and protein oxidation, and microbial counts. In this review, the principles of these emerging freezing technologies are introduced, and the impacts of these technologies on controlling the formation and growth of ice crystals and on complex changes of protein are also discussed. The current review shows that the novel freezing methods have positive effects on promoting the quality of frozen muscle. At a micro level, the majority of the novel methods have some certain ability on controlling the formation and growth of ice crystals, thus creating smaller, and more homogeneous and regular distribution of ice crystals, leading to better microstructure and enhanced quality attributes of frozen meats. Meanwhile, complex changes of protein take place under some of these novel freezing processes, and therefore the possible negative effect of the changes of protein should also be considered for commercial applications of these technologies in the frozen food industry.