The N-Degron Pathway Mediates ER-phagy.

The endoplasmic reticulum (ER) is susceptible to wear-and-tear and proteotoxic stress, necessitating its turnover. Here, we show that the N-degron pathway mediates ER-phagy. This autophagic degradation initiates when the transmembrane E3 ligase TRIM13 (also known as RFP2) is ubiquitinated via the lysine 63 (K63) linkage. K63-ubiquitinated TRIM13 recruits p62 (also known as sequestosome-1), whose complex undergoes oligomerization. The oligomerization is induced when the ZZ domain of p62 is bound by the N-terminal arginine (Nt-Arg) of arginylated substrates. Upon activation by the Nt-Arg, oligomerized TRIM13-p62 complexes are separated along with the ER compartments and targeted to autophagosomes, leading to lysosomal degradation. When protein aggregates accumulate within the ER lumen, degradation-resistant autophagic cargoes are co-segregated by ER membranes for lysosomal degradation. We developed synthetic ligands to the p62 ZZ domain that enhance ER-phagy for ER protein quality control and alleviate ER stresses. Our results elucidate the biochemical mechanisms and pharmaceutical means that regulate ER homeostasis.

Lipidation Engineering in Daptomycin Biosynthesis.

Lipopeptides are an important family of natural products, some of which are clinically used as antibiotics to treat multidrug-resistant pathogens. Although the lipid moieties play a crucial role in balancing antibacterial activity and hemolytic toxicity, modifying the lipid moieties has been challenging due to the complexity of the lipidation process in lipopeptide biosynthesis. Here, we show that the lipid profile can be altered by engineering both secondary and primary metabolisms, using daptomycin as an example. First, swapping the fatty acyl AMP ligase (FAAL) gene dptF with foreign FAAL homologs improved the fatty acyl specificity of the lipidation process for decanoic acid. Then, the introduction of Mycobacterium type I fatty acid synthase operon (MvFAS-Ib/MvAcpS) and Cryptosporidium thioesterase (CpTEII) enriched the fatty acid pool with decanoic acid in Streptomyces roseosporus. The engineered fatty acid metabolism eliminates the need for external decanoic acid supplementation by enabling S. roseosporus to biosynthesize decanoic acid. By complete engineering of the lipidation process, we achieved, for the first time, high-purity, natural production of daptomycin. The lipidation engineering approach we demonstrate here lays the foundation for the lipidation control in lipopeptide biosynthesis.

Effective Descriptor for Screening Single-Molecule Conductance Switches.

The adsorption-type molecular switch exhibits bistable states with an equivalently long lifetime at the organic/inorganic interface, promising reliable switching behavior and superior assembly ability in the electronic circuits at the molecular scale. However, the number of reported adsorption-type molecular switches is currently less than 10, and exploring these molecular switches poses a formidable challenge due to the intricate interplay occurring at the interface. To address this challenge, we have developed a model enabling the identification of diverse molecular switches on metal surfaces based on easily accessible physical characteristics. These characteristics primarily include the metal valency electron concentration, the work function of metal surfaces, and the electronegativity difference of molecules. Using this model, we identified 56 new molecular switches. Employing the gradient descent algorithm and statistical linear discriminant analysis, we constructed an explicit descriptor that establishes a relationship between the interfacial structure and chemical environment and the stability of molecular switches. The model's accuracy was validated through density functional theory calculations, achieving a 90% accuracy for aromatic molecular switches. The conductive switching behaviors were further confirmed by nonequilibrium Green's function transport calculations.

Promoter engineering of natural product biosynthetic gene clusters in actinomycetes: concepts and applications.

Covering 2011 to 2022Low titers of natural products in laboratory culture or fermentation conditions have been one of the challenging issues in natural products research. Many natural product biosynthetic gene clusters (BGCs) are also transcriptionally silent in laboratory culture conditions, making it challenging to characterize the structures and activities of their metabolites. Promoter engineering offers a potential solution to this problem by providing tools for transcriptional activation or optimization of biosynthetic genes. In this review, we summarize the 10 years of progress in promoter engineering approaches in natural products research focusing on the most metabolically talented group of bacteria actinomycetes.

Predictive Analysis in Oral Cancer Immunotherapy: Profiling Dual PD-L1-Positive Extracellular Vesicle Subtypes with Step-Wedge Microfluidic Chips.

PD-L1-positive extracellular vesicles (PD-L1+ EVs) play a pivotal role as predictive biomarkers in cancer immunotherapy. These vesicles, originating from immune cells (I-PD-L1+ EVs) and tumor cells (T-PD-L1+ EVs), hold distinct clinical predictive values, emphasizing the importance of deeply differentiating the PD-L1+ EV subtypes for effective liquid biopsy analyses. However, current methods such as ELISA lack the ability to differentiate their cellular sources. In this study, a novel step-wedge microfluidic chip that combines magnetic microsphere separation with single-layer fluorescence counting is developed. This chip integrates magnetic microspheres modified with anti-PD-L1 antibodies and fluorescent nanoparticles targeting EpCAM (tumor cell marker) or CD45 (immunocyte marker), enabling simultaneous quantification and sensitive analysis of PD-L1+ EV subpopulations in oral squamous cell carcinoma (OSCC) patients' saliva without background interference. Analysis results indicate reduced levels of I-PD-L1+ EVs in OSCC patients compared to those in healthy individuals, with varying levels of heterogeneous PD-L1+ EVs observed among different patient groups. During immunotherapy, responders exhibit decreased levels of total PD-L1+ EVs and T-PD-L1+ EVs, accompanied by reduced levels of I-PD-L1+ EVs. Conversely, nonresponders show increased levels of I-PD-L1+ EVs. Utilizing the step-wedge microfluidic chip allows for simultaneous detection of PD-L1+ EV subtypes, facilitating the precise prediction of oral cancer immunotherapy outcomes.

Thermal Emission Manipulation Enabled by Nano-Kirigami Structures.

The nano-kirigami metasurfaces have controllable 3D geometric parameters and dynamic transformation functions and therefore provide a strong spectral regulation capability of thermal emission. Here, the authors propose and demonstrate a dynamic and multifunctional thermal emitter based on deformable nano-kirigami structures, which can be actuated by electronic bias or mechanical compression. Selective emittance and the variation of radiation intensity/wavelength are achieved by adjusting the geometric shape and the transformation of the structures. Particularly, a thermal management device based on a composite structure of nano-kirigami and polydimethylsiloxane (PDMS) thin film is developed, which can dynamically switch the state of cooling and heating by simply pressing the device. The proposed thermal emitter designs with strong regulation capability and multiple dynamic adjustment strategies are desirable for energy and sensing applications and inspire further development of infrared emitters.

Phenazine biosynthesis protein MoPhzF regulates appressorium formation and host infection through canonical metabolic and noncanonical signaling function in Magnaporthe oryzae.

Microbe-produced secondary metabolite phenazine-1-carboxylic acid (PCA) facilitates pathogen virulence and defense mechanisms against competitors. Magnaporthe oryzae, a causal agent of the devastating rice blast disease, needs to compete with other phyllosphere microbes and overcome host immunity for successful colonization and infection. However, whether M. oryzae produces PCA or it has any other functions remains unknown. Here, we found that the MoPHZF gene encodes the phenazine biosynthesis protein MoPhzF, synthesizes PCA in M. oryzae, and regulates appressorium formation and host virulence. MoPhzF is likely acquired through an ancient horizontal gene transfer event and has a canonical function in PCA synthesis. In addition, we found that PCA has a role in suppressing the accumulation of host-derived reactive oxygen species (ROS) during infection. Further examination indicated that MoPhzF recruits both the endoplasmic reticulum membrane protein MoEmc2 and the regulator of G-protein signaling MoRgs1 to the plasma membrane (PM) for MoRgs1 phosphorylation, which is a critical regulatory mechanism in appressorium formation and pathogenicity. Collectively, our studies unveiled a canonical function of MoPhzF in PCA synthesis and a noncanonical signaling function in promoting appressorium formation and host infection.

SERS detection of volatile gas in spoiled pork with the Ag/MoS2 nano-flower cavity/PVDF micron-bowl cavity (FIB) substrate.

Putrescine and cadaverine are significant volatile indicators used to assess the degree of food spoilage. Herein, we propose a micro-nano multi cavity structure for surface-enhanced Raman spectroscopy (SERS) to analyze the volatile gas putrescine and cadaverine in decomposing food. The MoS2 nano-flowers are inserted into a PVDF micro-cavity through in-situ growth, followed by vacuum evaporation technology of Ag nanoparticles to form an Ag/MoS2 nano-flower cavity/PVDF micron-bowl cavity (FIB) substrate. The micro-nano multi cavity structure can improve the capture capacity of both light and gas, thereby exhibiting high sensitivity (EF = 7.71 × 107) and excellent capability for gas detection of 2-naphthalenethiol. The SERS detections of the putrescine and cadaverine are achieved in the spoiled pork samples with the FIB substrate. Therefore, this substrate can provide an efficient, accurate, and feasible method for the specific and quantitative detection in the food safety field.

Anomalous far-field polarization around bound states in the continuum in non-Bravais lattices.

It is generally believed that at-Γ bound states in the continuum (BICs) are enclosed by a linearly polarized vortex in momentum space when the structures have mirror (σz) symmetry, in-plane inversion (I) symmetry, and time reversal symmetry (T). Here, we reveal an anomalous situation in which at-Γ BICs can be enclosed by linearly and elliptically polarized far-field even when the σz, I, and T symmetries are all maintained in non-Bravais lattices, which is radically different from previous cognition. Asymmetric, diatomic structures are designed to elaborate this intriguing phenomenon. By controlling the geometric parameters or refractive indexes of the two meta-atoms, the far-field polarization around the at-Γ BICs gradually deviates from linear polarization and approaches circular polarization. Our findings reveal that non-Bravais lattices can provide a novel platform to manipulate the far-field polarization, showing important applications in quantum entanglement, structured light, and radiation modulation.

Ph3P═O-Catalyzed Reductive Deoxygenation of Alcohols.

Reductive deoxygenation of alcohols is particularly challenging because of the high bond dissociation energy of the C-OH bond and the poor leaving ability of the hydroxyl group. Herein we describe a Ph3P═O-catalyzed reductive deoxygenation of benzyl alcohols with PhSiH3 under an air atmosphere within 30 min of reaction time. The use of catalytic loading of Ph3P═O enhances the practicality of this protocol.

Immune response and protective efficacy of Streptococcus agalactiae vaccine coated with chitosan oligosaccharide for different immunization strategy in nile tilapia (Oreochromis niloticus).

In the past decade, the outbreak of Streptococcus agalactiae has caused significant economic losses in tilapia farming. Vaccine immunization methods and strategies have gradually evolved from single-mode to multi-mode overall prevention and control strategies. In this study, an inactivated vaccine of S. agalactiae with a chitosan oligosaccharide (COS) adjuvant was constructed using different administration methods: intraperitoneal injection (Ip), immersion combined with intraperitoneal injection (Im + Ip), immersion combined with oral administration (Im + Or), and oral administration (Or). Safety analysis revealed no adverse effects on tilapia, and the vaccine significantly promoted fish growth and development when administered through Im + Or or Or immunization. Following vaccination, innate immunity parameters including SOD, ACP and CAT activities were all significantly enhanced. Additionally, specific serum IgM antibodies reached their highest level at the 6th week post vaccination. Skin and intestinal mucus IgT antibodies reached peaked at the 6th and 7th week post vaccination, respectively. The relative peak expression values for IL-8, IL-12, MHC-I, MHC-II, IgM, IgT, CD4, CD8, TNFα, IFNγ from Im + Ip group were significantly higher than those in Ip group, Im + Or group and Or group in most cases (p < 0.05). Importantly, the relative protection survival of Im + Ip group was the highest (78.6%), followed by the Ip group (71.4%), the Or group (64.3%) and the Im + Or group (57.1%). In summary, this study encourages further research on multi-channel immunization strategies of other kinds of vaccines in other aquatic economic animals to improve their disease resistance.

Identification of potential novel targets for treating inflammatory bowel disease using Mendelian randomization analysis.

BACKGROUND: Inflammatory bowel disease (IBD) is a complex autoimmune disorder, although some medications are available for its treatment. However, the long-term efficacy of these drugs remains unsatisfactory. Therefore, there is a need to develop novel drug targets for IBD treatment. METHODS: We conducted two-sample Mendelian randomization (MR) analysis using Genome-Wide Association Study (GWAS) data to assess the causal relationships between plasma proteins and IBD and its subtypes. Subsequently, the presence of shared genetic variants between the identified plasma proteins and traits was explored using Bayesian co-localization. Phenome-wide MR was used to evaluate evaluated adverse effects, and drug target databases were examined for therapeutic potential. RESULTS: Using the Bonferroni correction (P < 3.56e-05), 17 protein-IBD pairs were identified. Notably, the genetic associations of IBD shared a common variant locus (PP.H4 > 0.7) with five proteins (MST1, IL12B, HGFAC, FCGR2A, and IL18R1). As a subtype of IBD, ulcerative colitis shares common variant loci with FCGR2A, IL12B, and MST1. In addition, we found that ANGPTL3, IL18R1, and MST1 share a common variant locus with Crohn's disease. Furthermore, phenome-wide MR analysis revealed that except for ANGPTL3, no other proteins showed potential adverse effects. In the drug database, identified plasma proteins such as FCGR2A and IL18R1 were found to be potential drug targets for the treatment of IBD and its subtypes. CONCLUSION: Six proteins (FCGR2A, IL18R1, MST1, HGFAC, IL12B, and ANGPTL3) were identified as potential drug targets for the treatment of IBD and its subtypes.

The N-terminal cysteine is a dual sensor of oxygen and oxidative stress.

Cellular homeostasis requires the sensing of and adaptation to intracellular oxygen (O2) and reactive oxygen species (ROS). The Arg/N-degron pathway targets proteins that bear destabilizing N-terminal residues for degradation by the proteasome or via autophagy. Under normoxic conditions, the N-terminal Cys (Nt-Cys) residues of specific substrates can be oxidized by dioxygenases such as plant cysteine oxidases and cysteamine (2-aminoethanethiol) dioxygenases and arginylated by ATE1 R-transferases to generate Arg-CysO2(H) (R-CO2). Proteins bearing the R-CO2 N-degron are targeted via Lys48 (K48)-linked ubiquitylation by UBR1/UBR2 N-recognins for proteasomal degradation. During acute hypoxia, such proteins are partially stabilized, owing to decreased Nt-Cys oxidation. Here, we show that if hypoxia is prolonged, the Nt-Cys of regulatory proteins can be chemically oxidized by ROS to generate Arg-CysO3(H) (R-CO3), a lysosomal N-degron. The resulting R-CO3 is bound by KCMF1, a N-recognin that induces K63-linked ubiquitylation, followed by K27-linked ubiquitylation by the noncanonical N-recognin UBR4. Autophagic targeting of Cys/N-degron substrates is mediated by the autophagic N-recognin p62/SQTSM-1/Sequestosome-1 through recognition of K27/K63-linked ubiquitin (Ub) chains. This Cys/N-degron-dependent reprogramming in the proteolytic flux is important for cellular homeostasis under both chronic hypoxia and oxidative stress. A small-compound ligand of p62 is cytoprotective under oxidative stress through its ability to accelerate proteolytic flux of K27/K63-ubiquitylated Cys/N-degron substrates. Our results suggest that the Nt-Cys of conditional Cys/N-degron substrates acts as an acceptor of O2 to maintain both O2 and ROS homeostasis and modulates half-lives of substrates through either the proteasome or lysosome by reprogramming of their Ub codes.

Evaluation of the Role of Tanshinone I in an In Vitro System of Charcot-Marie-Tooth Disease Type 2N.

Charcot-Marie-Tooth disease type 2N (CMT2N) is an inherited nerve disorder caused by mutations in the alanyl-tRNA synthetase (AlaRS) gene, resulting in muscle weakness and sensory issues. Currently, there is no cure for CMT2N. Here, we found that all five AlaRS mutations in the aminoacylation domain can interact with neuropilin-1 (Nrp1), which is consistent with our previous findings. Interestingly, three of these mutations did not affect alanine activation activity. We then performed a high-throughput screen of 2000 small molecules targeting the prevalent R329H mutant. Using thermal stability assays (TSA), biolayer interferometry (BLI), ATP consumption, and proteolysis assays, we identified Tanshinone I as a compound that binds to and modifies the conformation of the R329H mutant and other CMT-related AlaRS mutants interacting with Nrp1. Molecular docking and dynamic simulation studies further clarified Tanshinone I's binding mode, indicating its potential against various AlaRS mutants. Furthermore, co-immunoprecipitation (Co-IP) and pull-down assays showed that Tanshinone I significantly reduces the binding of AlaRS mutants to Nrp1. Collectively, these findings suggest that Tanshinone I, by altering the conformation of mutant proteins, disrupts the pathological interaction between AlaRS CMT mutants and Nrp1, potentially restoring normal Nrp1 function. This makes Tanshinone I a promising therapeutic candidate for CMT2N.

Design and impact assessment of policies to overcome oversupply in China's national carbon market.

China has adopted a national carbon emissions trading market to promote emission reductions, but until now, overallocation of allowances suffer low carbon prices and thus to unfulfilled emission reduction goals. We report a general equilibrium modeling that indicates the flexible compliance and price adjustment mechanism of the carbon market, along with explores the solution to the oversupply of allowances in the China's national carbon market. We find that, under the current policy, the initial loose allowance allocation decreases the overall carbon price, and simultaneously the total amount of banked carbon allowances reaches 4.880 billion tons in 2030, resulting in the level of carbon price cannot achieve NDC (Nationally Determined Contribution) targets. However, by introducing carbon market price adjustment schemes, we observe that the cumulative amount of allowances can effectively reduce, enabling the carbon price rising. Importantly, the amount of the supply of allowances decreases most under the benchmark decrease scenario, which increases the emission reduction pressure of the enterprises from the beginning, leading to the largest economic losses, the price-based adjustment mechanism raises the carbon price to expected level at the minimize economic losses, and the quantity-based adjustment mechanism is more sensitive to policy parameters compared to the price -based adjustment mechanism. These findings offer a promising avenue for selecting cost-effective price adjustment mechanism to improve price mechanism design for national carbon markets.

Effective Screening Descriptor for MXenes to Enhance Sulfur Reduction in Lithium-Sulfur Batteries.

MXenes, two-dimensional transition (2D) metal carbides/nitrides, have shown promise as cathodic catalysts for accelerating the conversion of lithium polysulfides (LiPSs) in lithium-sulfur (Li-S) batteries due to their diverse redox-active sites and rapid electron transfer. However, efficiently screening the optimal cathodic catalysts out of thousands of MXenes is challenging. To address this, we developed a model that accurately predicts the thermodynamic energy barrier of the rate-limiting step in Li-S batteries. Our model relates the local chemical reactivity of the MXene sites to the p-band center of the terminations and the electronegativity of subsurface transition metals. The accuracy of the model was verified through density functional theory calculations and contrast experiments in pure and Zn-doping MXenes qualitatively. By utilizing this model, we screened a large library of MXenes (27 types of five-atom-layer MXenes) and identified Ti2CS2, Mo2CS2, and W2CS2 as potential cathodic catalysts for Li-S batteries.

Biology and Roles in Diseases of Selenoprotein I Characterized by Ethanolamine Phosphotransferase Activity and Antioxidant Potential.

Selenoprotein I (SELENOI) has been demonstrated to be an ethanolamine phosphotransferase (EPT) characterized by a nonselenoenzymatic domain and to be involved in the main synthetic branch of phosphatidylethanolamine (PE) in the endoplasmic reticulum. Therefore, defects of SELENOI may affect the health status through the multiple functions of PE. On the other hand, selenium (Se) is covalently incorporated into SELENOI as selenocysteine (Sec) in its peptide, which forms a Sec-centered domain as in the other members of the selenoprotein family. Unlike other selenoproteins, Sec-containing SELENOI was formed at a later stage of animal evolution, and the high conservation of the structural domain for PE synthesis across a wide range of species suggests the importance of EPT activity in supporting the survival and evolution of organisms. A variety of factors, such as species characteristics (age and sex), diet and nutrition (dietary Se and fat intakes), SELENOI-specific properties (tissue distribution and rank in the selenoproteome), etc., synergistically regulate the expression of SELENOI in a tentatively unclear interaction. The N- and C-terminal domains confer 2 distinct biochemical functions to SELENOI, namely PE regulation and antioxidant potential, which may allow it to be involved in numerous physiological processes, including neurological diseases (especially hereditary spastic paraplegia), T cell activation, tumorigenesis, and adipocyte differentiation. In this review, we summarize advances in the biology and roles of SELENOI, shedding light on the precise regulation of SELENOI expression and PE homeostasis by dietary Se intake and pharmaceutical or transgenic approaches to modulate the corresponding pathological status.

Tf2O as a CF3 Source for the Synthesis of Trifluoromethoxylation Reagent nC4F9SO3CF3.

Described herein is the convenient synthesis of an efficient trifluoromethoxylation reagent, nC4F9SO3CF3, by using cheap and widely available reagents and without the need of any tedious column chromatography purification procedure.

Dehydroxylative Sulfonylation of Alcohols.

Described here is the R3P/ICH2CH2I-promoted dehydroxylative sulfonylation of alcohols with a variety of sulfinates. In contrast to previous dehydroxylative sulfonylation methods, which are usually limited to active alcohols, such as benzyl, allyl, and propargyl alcohols, our protocol can be extended to both active and inactive alcohols (alkyl alcohols). Various sulfonyl groups can be incorporated, such as CF3SO2 and HCF2SO2, which are fluorinated groups of interest in pharmaceutical chemistry and the installation of which has received increasing attention. Notably, all reagents are cheap and widely available, and moderate to high yields were obtained within 15 min of reaction time.

Immune response and protective efficacy of mannosylated polyethylenimine (PEI) as an antigen delivery vector, administered with a Streptococcus agalactiae DNA vaccine in Nile tilapia (Oreochromis niloticus).

This study examined the effectiveness of a DNA vaccine for S. agalactiae that was delivered by mannose-based polyethyleneimine (Man-PEI). The results showed that Man-PEI/pcDNA-Sip stimulated a higher serum antibody titer compared to control or other vaccine groups (p < 0.05). Additionally, it induced higher expression of immune-related genes, and increased activities of superoxide dismutase (SOD), acid phosphatase (ACP) and alkaline phosphatase (AKP). Furthermore, the Man-PEI/pcDNA-Sip group showed an improved relative percent survival (RPS) of 85.71%. These results demonstrate the potential value of Man-PEI as a vaccine delivery vehicle, and suggest that it can be effective in boosting the immune protective rate induced by pcDNA-Sip vaccines.