TCR activation directly stimulates PYGB-dependent glycogenolysis to fuel the early recall response in CD8+ memory T cells.

Glycolysis facilitates the rapid recall response of CD8+ memory T (Tm) cells. However, it remains unclear whether Tm cells uptake exogenous glucose or mobilize endogenous sugar to fuel glycolysis. Here, we show that intracellular glycogen rather than extracellular glucose acts as the major carbon source for the early recall response. Following antigenic stimulation, Tm cells exhibit high glycogen phosphorylase (brain form, PYGB) activity, leading to glycogenolysis and release of glucose-6-phosphate (G6P). Elevated G6P mainly flows to glycolysis but is also partially channeled to the pentose phosphate pathway, which maintains the antioxidant capacity necessary for later recall stages. Mechanistically, TCR signaling directly induces phosphorylation of PYGB by LCK-ZAP70. Functionally, the glycogenolysis-fueled early recall response of CD8+ Tm cells accelerates the clearance of OVA-Listeria monocytogenes in an infected mouse model. Thus, we uncover a specific dependency on glycogen for the initial activation of memory T cells, which may have therapeutic implications for adaptive immunity.

Novel players in organogenesis and flavonoid biosynthesis in cucumber glandular trichomes.

Glandular trichomes (GTs) are outgrowths of plant epidermal cells that secrete and store specialized secondary metabolites that protect plants against biotic and abiotic stresses and have economic importance for human use. While extensive work has been done to understand the molecular mechanisms of trichome organogenesis in Arabidopsis (Arabidopsis thaliana), which forms unicellular, nonglandular trichomes (NGTs), little is known about the mechanisms of GT development or regulation of secondary metabolites in plants with multicellular GTs. Here, we identified and functionally characterized genes associated with GT organogenesis and secondary metabolism in GTs of cucumber (Cucumis sativus). We developed a method for effective separation and isolation of cucumber GTs and NGTs. Transcriptomic and metabolomic analyses showed that flavonoid accumulation in cucumber GTs is positively associated with increased expression of related biosynthesis genes. We identified 67 GT development-related genes, the functions of 7 of which were validated by virus-induced gene silencing. We further validated the role of cucumber ECERIFERUM1 (CsCER1) in GT organogenesis by overexpression and RNA interference transgenic approaches. We further show that the transcription factor TINY BRANCHED HAIR (CsTBH) serves as a central regulator of flavonoid biosynthesis in cucumber GTs. Work from this study provides insight into the development of secondary metabolite biosynthesis in multicellular GTs.

Preparation of recombinant neuritin protein.

Neuritin plays an important role in promoting nerve injury repair and maintaining synaptic plasticity, making it a potential therapeutic target for the treatment of nerve injury and neurodegenerative diseases. The present study aimed to obtain an active, unlabeled neuritin protein. Initially, a neuritin protein expression system with an enterokinase site was constructed in Escherichia coli. After optimizing induction conditions and screening for high expression, a neuritin recombinant protein with purity exceeding 85% was obtained through Ni-affinity chromatography. Subsequently, unlabeled neuritin with a molecular weight of 11 kDa was obtained through the enzymatic cleavage of the His label using an enterokinase. Furthermore, a neuritin recombinant protein with purity exceeding 95% was obtained using gel chromatography. Functional investigations revealed that neurite outgrowth of PC12 cells was stimulated by the isolated neuritin. This study establishes a method to obtain active and unlabeled neuritin protein, providing a foundation for subsequent research on its biological functions.

Zinc Finger-Homeodomain Transcriptional Factors (ZHDs) in Cucumber (Cucumis sativus L.): Identification, Evolution, Expression Profiles, and Function under Abiotic Stresses.

Cucumber (Cucumis sativus L.) is a globally prevalent and extensively cultivated vegetable whose yield is significantly influenced by various abiotic stresses, including drought, heat, and salinity. Transcription factors, such as zinc finger-homeodomain proteins (ZHDs), a plant-specific subgroup of Homeobox, play a crucial regulatory role in stress resistance. In this study, we identified 13 CsZHDs distributed across all six cucumber chromosomes except chromosome 7. Phylogenetic analysis classified these genes into five clades (ZHDI-IV and MIF) with different gene structures but similar conserved motifs. Collinearity analysis revealed that members of clades ZHD III, IV, and MIF experienced amplification through segmental duplication events. Additionally, a closer evolutionary relationship was observed between the ZHDs in Cucumis sativus (C. sativus) and Arabidopsis thaliana (A. thaliana) compared to Oryza sativa (O. sativa). Quantitative real-time PCR (qRT-PCR) analysis demonstrated the general expression of CsZHD genes across all tissues, with notable expression in leaf and flower buds. Moreover, most of the CsZHDs, particularly CsZHD9-11, exhibited varying responses to drought, heat, and salt stresses. Virus-induced gene silencing (VIGS) experiments highlighted the potential functions of CsZHD9 and CsZHD10, suggesting their positive regulation of stomatal movement and responsiveness to drought stress. In summary, these findings provide a valuable resource for future analysis of potential mechanisms underlying CsZHD genes in response to stresses.

Broadband Achromatic Quarter-Waveplate Using 2D Hybrid Copper Halide Single Crystals.

Achromatic quarter waveplates (A-QWPs), traditionally constructed from multiple birefringent crystals, can modulate light polarization and retardation across a broad range of wavelengths. This mechanism is inherently related to phase retardation controlled by the fast and slow axis of stacked multi-birefringent crystals. However, the conventional design of A-QWPs requires the incorporation of multiple birefringent crystals, which complicates the manufacturing process and raises costs. Here, we report the discovery of a broadband (540-1060 nm) A-QWP based on a two-dimensional (2D) layered hybrid copper halide (HCH) perovskite single crystal. The 2D copper chloride (CuCl6) layers of the HCH crystal undergo Jahn-Teller distortion and subsequently trigger the in-plane optical birefringence. Its broad range of the wavelength response as an A-QWP is a consequence of the out-of-plane mosaicity formed among the stacked inorganic layers during the single-crystal self-assembly process in the solution phase. Given the versatility of 2D hybridhalide perovskites, the 2D HCH crystal offers a promising approach for designing cost-effective A-QWPs and the ability to integrate other optical devices.

The forkhead box protein P3 gene rs3761548 promoter polymorphism confers a genetic contribution to the risk of preeclampsia: A systematic review and meta-analysis.

Various studies have investigated the risk of preeclampsia with the forkhead box protein P3 (FOXP3) gene rs2232365 and rs3761548 polymorphisms. However, the results remained contradictory. A comprehensive literature search was conducted using the Cochrane Library, PubMed, and Web of Science (up to Oct 11, 2021). Meta-analysis was carried out in the R language environment for statistical computing and graphics. A fixed-effect or random-effects model was used according to the statistical significance of heterogeneity among included studies. The pooled odds ratios and corresponding 95% confidence intervals were calculated to estimate the strength of the effect. For the rs2232365 polymorphism, statistical significance was detected neither in the overall population nor among the East Asian and West Asian subgroups. However, for rs3761548, the summarized statistics revealed a significant association between the C allele carriage and preeclampsia risk in the homozygote, heterozygote, and dominant models. The further stratified analysis found this effect might be specific to West-South Asian ethnic subgroups. To sum up, this meta-analysis showed that the FOXP3 rs3761548 polymorphism was significantly associated with preeclampsia susceptibility, and it had a deleterious effect especially in the West-South Asian population. In contrast, rs2232365 may serve as neither a protective nor a risk factor for preeclampsia onset.

Fusion with CTP increases the stability of recombinant neuritin.

Neuritin is a vital neurotrophin that plays an essential role in recovery from nerve injury and neurodegenerative diseases and may become a new target for treating these conditions. However, improving neuritin protein stability is an urgent problem. In this study, to obtain active and stable neuritin proteins, we added a carboxyl-terminal peptide (CTP) sequence containing four O-linked glycosylation sites to the C-terminus of neuritin and cloned it into the Chinese hamster ovary (CHO) expression system. The neuritin-CTP protein was purified using a His-Tag purification strategy after G418 screening of stable high-expression cell lines. Ultimately, we obtained neuritin-CTP protein with a purity >90%. Functional analyses showed that the purified neuritin-CTP protein promoted the neurite outgrowth of PC12 cells, and stability experiments showed that neuritin stability was increased by adding CTP. These results indicate that neuritin protein-CTP fusion effectively increases stability without affecting secretion and activity. This study offers a sound strategy for improving the stability of neuritin protein and provides material conditions for further study of the function of neuritin.

Spatio-temporal variation of bacterial community structure in two intertidal sediment types of Jiaozhou Bay.

The intertidal sediment environment is dynamic and the biofilm bacterial community within it must constantly adapt, but an understanding of the differences in the biofilm bacterial community within sediments of different types is still relatively limited. The semi-enclosed Jiaozhou Bay has a temperate monsoon climate, with strong currents at the mouth of the bay. In this study, the structure of the bacterial community in Jiaozhou Bay sediment biofilms are described using high-throughput 16 S rRNA gene sequencing and the effects of temporal change and different sediment environment types are discussed. Alpha diversity was significantly higher in sandy samples than in muddy samples. Sandy sediments with increased heterogeneity promote bacterial aggregation. Beta diversity analysis showed significant differences between sediment types and between stations. Proteobacteria and Acidobacteria were significantly more abundant at ZQ, while Campilobacterota was significantly more abundant at LC. The relative abundances of Bacteroidetes, Campilobacterota, Firmicutes, and Chloroflexi were significantly higher in the muddy samples, while Actinobacteria and Proteobacteria were higher in the sandy samples. There were different phylum-level biomarkers between sediment types at different stations. There were also different patterns of functional enrichment in biogeochemical cycles between sediment types and stations with the former having more gene families that differed significantly, highlighting their greater role in determining bacterial function. Bacterial amplicon sequence variant variation between months was less than KEGG ortholog variation between months, presumably the temporal change had an impact on shaping the intertidal sediment bacterial community, although this was less clear at the gene family level. Random forest prediction yielded a combination of 43 family-level features that responded well to temporal change, reflecting the influence of temporal change on sediment biofilm bacteria.

Identification and Functional Characterization of CsMYCs in Cucumber Glandular Trichome Development.

Glandular trichomes (GTs), specialized structures formed by the differentiation of plant epidermal cells, are known to play important roles in the resistance of plants to external biotic and abiotic stresses. These structures are capable of storing and secreting secondary metabolites, which often have important agricultural and medicinal values. In order to better understand the molecular developmental mechanisms of GTs, studies have been conducted in a variety of crops, including tomato (Solanum lycopersicum), sweetworm (Artemisia annua), and cotton (Gossypium hirsutum). The MYC transcription factor of the basic helix-loop-helix (bHLH) transcription factor family has been found to play an important role in GT development. In this study, a total of 13 cucumber MYC transcription factors were identified in the cucumber (Cucumis sativus L.) genome. After performing phylogenetic analyses and conserved motifs on the 13 CsMYCs in comparison to previously reported MYC transcription factors that regulate trichome development, seven candidate MYC transcription factors were selected. Through virus-induced gene silencing (VIGS), CsMYC2 is found to negatively regulate GT formation while CsMYC4, CsMYC5, CsMYC6, CsMYC7, and CsMYC8 are found to positively regulate GT formation. Furthermore, the two master effector genes, CsMYC2 and CsMYC7, are observed to have similar expression patterns indicating that they co-regulate the balance of GT development in an antagonistic way.

Structural Basis of the Immunity Mechanisms of Pediocin-like Bacteriocins.

Pediocin-like bacteriocins, also designated class IIa bacteriocins, are ribosomally synthesized antimicrobial peptides targeting species closely related to the producers. They act on the cytoplasmic membrane of Gram-positive cells by dissipating the transmembrane electrical potential through pore formation with the mannose phosphotransferase system (man-PTS) as the target/receptor. Bacteriocin-producing strains also synthesize a cognate immunity protein that protects them against their own bacteriocins. Herein, we report the cryo-electron microscopy structure of the bacteriocin-receptor-immunity ternary complex from Lactobacillus sakei. The complex structure reveals that pediocin-like bacteriocins bind to the same position on the Core domain of man-PTS, while the C-terminal helical tails of bacteriocins delimit the opening range of the Core domain away from the Vmotif domain to facilitate transmembrane pore formation. Upon attack of bacteriocins from the extracellular side, man-PTS exposes its cytosolic side for recognition of the N-terminal four-helix bundle of the immunity protein. The C-terminal loop of the immunity protein then inserts into the pore and blocks leakage induced by bacteriocins. Elucidation of the toxicity and immunity mechanisms of pediocin-like bacteriocins could support the design of novel bacteriocins against antibiotic-resistant pathogenic bacteria. IMPORTANCE Pediocin-like bacteriocins, ribosomally synthesized antimicrobial peptides, are generally co-expressed with cognate immunity proteins to protect the bacteriocin-producing strain from its own bacteriocin. Bacteriocins are considered potential alternatives to conventional antibiotics in the context of the bacterial resistance crisis, but the immunity mechanism is unclear. This study uncovered the mechanisms of action and immunity of class IIa bacteriocins.

Structural Basis of Pore Formation in the Mannose Phosphotransferase System by Pediocin PA-1.

Bacteriocins are ribosomally synthesized bacterial antimicrobial peptides that have a narrow spectrum of antibacterial activity against species closely related to the producers. Pediocin-like (or class IIa) bacteriocins (PLBs) exhibit antibacterial activity against several Gram-positive bacterial strains by forming pores in the cytoplasmic membrane of target cells with a specific receptor, the mannose phosphotransferase system (man-PTS). In this study, we report the cryo-electron microscopy structures of man-PTS from Listeria monocytogenes alone and its complex with pediocin PA-1, the first and most extensively studied representative PLB, at resolutions of 3.12 and 2.45 Å, respectively. The structures revealed that the binding of pediocin PA-1 opens the Core domain of man-PTS away from its Vmotif domain, creating a pore through the cytoplasmic membranes of target cells. During this process, the N-terminal ß-sheet region of pediocin PA-1 can specifically attach to the extracellular surface of the man-PTS Core domain, whereas the C-terminal half penetrates the membrane and cracks the man-PTS like a wedge. Thus, our findings shed light on a design of novel PLBs that can kill the target pathogenic bacteria. IMPORTANCE Listeria monocytogenes is a ubiquitous microorganism responsible for listeriosis, a rare but severe disease in humans, who become infected by ingesting contaminated food products (i.e., dairy, meat, fish, and vegetables): the disease has a fatality rate of 33%. Pediocin PA-1 is an important commercial additive used in food production to inhibit Listeria species. The mannose phosphotransferase system (man-PTS) is responsible for the sensitivity of Listeria monocytogenes to pediocin PA-1. In this study, we report the cryo-EM structures of man-PTS from Listeria monocytogenes alone and its complex with pediocin PA-1 at resolutions of 3.12 and 2.45 Å, respectively. Our results facilitate the understanding of the mode of action of class IIa bacteriocins as an alternative to antibiotics.

Reassessing acetyl-CoA supply and NADPH availability for mevalonate biosynthesis from glycerol in Escherichia coli.

Mevalonate is an important platform compound for the biosynthesis of isoprenoids. It can be synthesized from acetyl-CoA in the presence of nicotinamide adenine dinucleotide phosphate (NADPH) by the introduced mvaES operon in Escherichia coli. The influences of E. coli hosts, acetyl-CoA supply, and NADPH availability were assessed and engineered to improve the production titer and yield of mevalonate from glycerol. As a result, E. coli DH5α was found to be the best host with high specific capability and titer of mevalonate from glycerol. Through the engineering of phosphoketolase-phosphotransacetylase (xPK-PTA) bypass and NADPH availability, a final titer of 7.21 g/L with a specific capability of 1.36 g/g dry cell weight was gained in flask culture. Our work could offer new information to metabolically engineer the mevalonate pathway for the efficient production of isoprenoids.

Characterization of a heptapeptide-modified microsphere for oriented antibody immobilization.

Oriented immobilization of antibodies is important for the effective recognition of target antigens. In this paper, a heptapeptide ligand, HWRGWVC (HC7), was modified onto non-porous monosized poly(glyceryl methacrylate) (pGMA) microspheres (named pGMA-HC7) to explore the antibody immobilization behaviors. Characterization of the microspheres by particle size analyzer, scanning electron microscopy, Fourier transform infrared spectroscopy, and reversed-phase chromatography proved the success of each fabrication step. The capacity and activity of antibody immobilization through HC7 were studied using immunoglobulin G (IgG) as a model antibody and horseradish peroxidase (HRP) as a model antigen. Additionally, IgG immobilizations on pGMA microspheres by nonspecific adsorption and covalent coupling through carbodiimide chemistry were conducted for comparison. pGMA-HC7 exhibited an IgG adsorption capacity of 3-4 mg/g in 10 min by the specific binding of HC7 without nonspecific interactions. Notably, the ligand HC7 showed a by two orders of magnitude stronger affinity for IgG than its original hexapeptide ligand HWRGWV. Moreover, the capacity and activity of the immobilized anti-HRP antibody on pGMA-HC7 were 1.6-fold and 3-fold higher than those of the covalent coupling, respectively. The results proved the superior role of HWRGWVC in the affinity binding of antibody and the potential of pGMA-HC7-25 in immunoassay and immunodiagnostic applications.

Long non-coding RNAs regulate Wnt signaling during feather regeneration.

Long non-coding RNAs (lncRNAs) are non-protein coding transcripts that are involved in a broad range of biological processes. Here, we examine the functional role of lncRNAs in feather regeneration. RNA-seq profiling of the regenerating feather blastema revealed that Wnt signaling is among the most active pathways during feather regeneration, with Wnt ligands and their inhibitors showing distinct expression patterns. Co-expression analysis identified hundreds of lncRNAs with similar expression patterns to either the Wnt ligands (the Lwnt group) or their downstream target genes (the Twnt group). Among these, we randomly picked two lncRNAs in the Lwnt group and three lncRNAs in the Twnt group to validate their expression and function. Members in the Twnt group regulated feather regeneration and axis formation, whereas members in the Lwnt group showed no obvious phenotype. Further analysis confirmed that the three Twnt group members inhibit Wnt signal transduction and, at the same time, are downstream target genes of this pathway. Our results suggest that the feather regeneration model can be utilized to systematically annotate the functions of lncRNAs in the chicken genome.

Experimental demonstration and investigation of vortex circular Pearcey beams in a dynamically shaped fashion.

Optical vortex, typically characterized by a helical phase front, results in a possession of orbital angular momentum. In recent years, teleportation of the vortex mode using novel beams with peculiar features has gained great interest. Here, we experimentally demonstrate the propagation dynamics for a new class of the auto-focusing vortex circular Pearcey beam (VCPB), which is theoretically described by delivering the coaxial or off-axial spiral phases into the circular Pearcey beam (CPB), forming the crescent or bottle-like focal structure with self-rotation. Notably, such a hybrid beam with various types is experimentally obtained through a digital micromirror device (DMD) with the binary amplitude holography, and this DMD-based modulation scheme combined with controllable vortex modes enables dynamic switching among the VCPBs. We also measure the topological phase by interferometry and we explain the beam property on the basis of Poynting vector, showing a good agreement with the simulations. Further, the number, location and mode of embedded vortices could offer multiple dimensions of flexibility for target beam modulation, thus the experimentally controllable VCPBs will bring potential to high-speed optical communications and particle manipulations that require dynamic shaping.

Two dimensional honeycomb-kagome Be3Pb2: a mechanically flexible topological insulator with high intrinsic carrier mobilities.

We theoretically predict a stable 2D nanosheet consisting of Pb and Be atoms sited at the honeycomb and kagome sites, respectively, forming a mixed honeycomb-kagome phase of Be3Pb2. Without the spin-orbit interaction, its band structure resembles that of honeycomb-structured graphene, namely, the valence and conduction bands touch at isolated points, whose energies linearly depend on the momentum. The presence of spin-orbit coupling (SOC), however, would result in a small bandgap opening, ∼116 meV. So, the SOC induces an electronic phase transition from a semimetal to a semiconductor. A coarse estimation based on the deformation potential method gives rise to very high carrier mobilities which are at least comparable to those of black phosphorene. Most interestingly, the 2D Be3Pb2 shows a non-trivial topology in the electronic structure accompanying the SOC induced band gap opening. Hence, 2D Be3Pb2 would be a versatile candidate for many applications, e.g., nanoelectronic devices.

Distribution characteristics and risk assessment of TBBPA in seawater and zooplankton in northern sea areas, China.

Tetrabromobisphenol-A (TBBPA) is a typical persistent organic pollutant (POP) that is harmful to the environment and organisms. It easily accumulates in organisms and is transmitted along the food chain or food web for long distances and long periods of time. The experiment was designed to assess the TBBPA pollution levels in marine environments via environmental sample testing and risk assessment. TBBPA levels in seawater and zooplankton samples at each station (n = 38) were detected, whereafter the bioaccumulation factor (BAF) and risk quotient (RQ) were calculated to evaluate the potential bioaccumulation and ecological risk of TBBPA to zooplankton, respectively. The results showed that TBBPA was widely detected in surface seawater and zooplankton samples in the Yellow Sea and Bohai Sea, with levels ranging from ND (non-detected) to 0.46 µg/L and ND to 9.83 µg/kg (wet weight), respectively. In both the Yellow Sea and Bohai Sea, the distance from the shore was one of the main factors affecting the TBBPA concentration in seawater, regardless of visibility. The BAF was significantly correlated with the TBBPA content in zooplankton samples (P < 0.01), which ranged from 372.32 to 29,941.55, indicating that TBBPA exhibits an obvious bioaccumulation risk to marine zooplankton. The ecological risk assessment indicated that TBBPA levels in seawater pose a high ecotoxicity risk to zooplankton (RQ > 1). This finding suggests that both the significant bioaccumulation of TBBPA in marine ecosystems and its potential ecological risks cannot be ignored.

Sensitively tuning the thermal conductivity of diamane via engineering the mass of functional groups.

Sensitively tuned thermal conductivity is highly desired for many practical applications, e.g. thermoelectricity and thermal metamaterials. Our theoretical calculations reveal that the thermal conductivities of functionalized two-dimensional (2D) materials show a rapid response to the increasing mass of functional groups, in which we take the newly synthesized diamane as an example and artificially tune the mass of hydrogen atoms to mimic the surface ligands of different masses. Our results indicate the sensitive influence of the mass of functional groups on the vibration and phonon transport properties of 2D materials. As the mass increases, the phonons are appreciably softened which results in reduced group velocities and the squeezed distribution of phonons in the frequency domain. The latter factor leads to an enlarged phonon-scattering phase space. Consequently, the intensified phonon-phonon scattering combined with the reduced group velocities could make the thermal conductivities decrease by ∼80%. Our findings suggest an intriguing strategy to sensitively tune the thermal conductivities of 2D materials via tailoring the mass of functional groups.

Parameterization of a COMPASS force field for single layer blue phosphorene.

We parameterize an accurate force field for single-layer blue phosphorene based on the framework of COMPASS (a nomenclature of condensed-phase optimized molecular potentials for atomistic simulation studies). During parameterization, the biaxial-strained samples and blue phosphorene nanotubes, as well as the phonon dispersion, are adopted as training sets. The combination of genetic algorithm and the simplex method finally leads to optimized parameters of the COMPASS force field whose accuracy is manifested by the excellent agreement between mechanical and vibrational properties predicted by our best-fitted COMPASS model and the ones by first-principles calculations. Such a high-accurate force field would be a good starting point for studying many physical properties of blue phosphorene based materials.

Smurf1 restricts the antiviral function mediated by USP25 through promoting its ubiquitination and degradation.

Protein ubiquitination and deubiquitination enzymes are widely involved in innate immune responses. The ubiquitin specific protease 25 (USP25), a deubiquitinating enzyme, has been demonstrated to play an important role in virus infection and immunity. However, how USP25 is degraded and regulated by E3 ubiquitin ligases remains poorly understood. Here, we identified Smad ubiquitin regulatory factor 1(Smurf1) as a first novel E3 ubiquitin ligase of USP25. Smurf1 overexpression decreases USP25 protein turnover, and the E3 ligase enzymatic activity of Smurf1 is required for USP25 degradation. Additionally, Smurf1-mediated degradation of USP25 is via promoting the K48-linkage polyubiquitination of USP25 in an ubiquitin proteasome dependent pathway. Importantly, USP25 overexpression restricts vesicular stomatitis virus (VSV) replication and the restriction of VSV replication by USP25 is enhanced in Smurf1 stable knock down cells. Therefore, our study firstly identified that Smurf1 negatively regulated the antiviral function mediated by USP25. Our findings revealed a previously unrecognized role of Smurf1 acting on USP25 and also their roles in the regulation of VSV replications.