Structural basis of K63-ubiquitin chain formation by the Gordon-Holmes syndrome RBR E3 ubiquitin ligase RNF216.

An increasing number of genetic diseases are linked to deregulation of E3 ubiquitin ligases. Loss-of-function mutations in the RING-between-RING (RBR) family E3 ligase RNF216 (TRIAD3) cause Gordon-Holmes syndrome (GHS) and related neurodegenerative diseases. Functionally, RNF216 assembles K63-linked ubiquitin chains and has been implicated in regulation of innate immunity signaling pathways and synaptic plasticity. Here, we report crystal structures of key RNF216 reaction states including RNF216 in complex with ubiquitin and its reaction product, K63 di-ubiquitin. Our data provide a molecular explanation for chain-type specificity and reveal the molecular basis for disruption of RNF216 function by pathogenic GHS mutations. Furthermore, we demonstrate how RNF216 activity and chain-type specificity are regulated by phosphorylation and that RNF216 is allosterically activated by K63-linked di-ubiquitin. These molecular insights expand our understanding of RNF216 function and its role in disease and further define the mechanistic diversity of the RBR E3 ligase family.

Oligomerization-driven MLKL ubiquitylation antagonizes necroptosis.

Mixed lineage kinase domain-like (MLKL) is the executioner in the caspase-independent form of programmed cell death called necroptosis. Receptor-interacting serine/threonine protein kinase 3 (RIPK3) phosphorylates MLKL, triggering MLKL oligomerization, membrane translocation and membrane disruption. MLKL also undergoes ubiquitylation during necroptosis, yet neither the mechanism nor the significance of this event has been demonstrated. Here, we show that necroptosis-specific multi-mono-ubiquitylation of MLKL occurs following its activation and oligomerization. Ubiquitylated MLKL accumulates in a digitonin-insoluble cell fraction comprising organellar and plasma membranes and protein aggregates. Appearance of this ubiquitylated MLKL form can be reduced by expression of a plasma membrane-located deubiquitylating enzyme. Oligomerization-induced MLKL ubiquitylation occurs on at least four separate lysine residues and correlates with its proteasome- and lysosome-dependent turnover. Using a MLKL-DUB fusion strategy, we show that constitutive removal of ubiquitin from MLKL licences MLKL auto-activation independent of necroptosis signalling in mouse and human cells. Therefore, in addition to the role of ubiquitylation in the kinetic regulation of MLKL-induced death following an exogenous necroptotic stimulus, it also contributes to restraining basal levels of activated MLKL to avoid unwanted cell death.

High-Durability Stacked Disc-Type Rolling Triboelectric Nanogenerators for Environmental Monitoring Around Charging Buoys of Unmanned Ships.

Triboelectric nanogenerator (TENG) as a means of energy harvesting can effectively harvest ocean wave energy, but the energy conversion efficiency and stability of the device during long-term operations are still problems that must be solved for TENGs. Decreasing the frictional resistance between two triboelectric material surfaces is one of the critical approaches for improving the device efficiency and durability. In this work, a novel stacked disc-type rolling triboelectric nanogenerator (SDR-TENG) is designed and fabricated for low-frequency water wave energy harvesting. After 860 000 working cycles, the electrical output attenuation of the SDR-TENG basic unit is less than 5%, showing excellent device durability. Under the simulated water wave conditions, the SDR-TENG with four rolling TENG units can produce an output current of 84.4 µA and an output power of 7.6 mW, corresponding to an effective power density of 16.8 W m-3. This work not only proposes a strategy to effectively enhance the durability of the devices, but also provides a feasible solution for monitoring the surrounding environment of the charging buoys of unmanned ships.

van der Waals Self-Epitaxial Growth of Inch-Sized Superconducting Niobium Diselenide Films.

Ultrathin superconducting films are the basis of superconductor devices. van der Waals (vdW) NbSe2 with noncentrosymmetry exhibits exotic superconductivity and shows promise in superconductor electronic devices. However, the growth of inch-scale NbSe2 films with layer regulation remains a challenge because vdW structural material growth is strongly dependent on the epitaxial guidance of the substrate. Herein, a vdW self-epitaxy strategy is developed to eliminate the substrate driving force in film growth and realize inch-sized NbSe2 film growth with thicknesses from 2.1 to 12.1 nm on arbitrary substrates. The superconducting transition temperature of 5.1 K and superconducting transition width of 0.30 K prove the top homogeneity and quality of superconductivity among all of the synthetic NbSe2 films. Coupled with a large area and substrate compatibility, this work paves the way for developing NbSe2 superconductor electronics.

A Fusion of Taq DNA Polymerase with the CL7 Protein from Escherichia coli Remarkably Improves DNA Amplification.

DNA polymerases are important enzymes that synthesize DNA molecules and therefore are critical to various scientific fields as essential components of in vitro DNA synthesis reactions, including PCR. Modern diagnostics, molecular biology, and genetic engineering require DNA polymerases with improved performance. This study aimed to obtain and characterize a new CL7-Taq fusion DNA polymerase, in which the DNA coding sequence of Taq DNA polymerase was fused with that of CL7, a variant of CE7 (Colicin E7 DNase) from Escherichia coli. The resulting novel recombinant open reading frame was cloned and expressed in E. coli. The recombinant CL7-Taq protein exhibited excellent thermostability, extension rate, sensitivity, and resistance to PCR inhibitors. Our results showed that the sensitivity of CL7-Taq DNA polymerase was 100-fold higher than that of wild-type Taq, which required a template concentration of at least 1.8 × 105 nM. Moreover, the extension rate of CL7-Taq was 4 kb/min, which remarkably exceeded the rate of Taq DNA polymerase (2 kb/min). Furthermore, the CL7 fusion protein showed increased resistance to inhibitors of DNA amplification, including lactoferrin, heparin, and blood. Single-cope human genomic targets were readily available from whole blood, and pretreatment to purify the template DNA was not required. Thus, this is a novel enzyme that improved the properties of Taq DNA polymerase, and thus may have wide application in molecular biology and diagnostics.

Mapping China's reserved arable lands and its sustainable cropping layout.

BACKGROUND: Reserved arable lands in China is of great significance for rationally allocating crop planting structures, alleviating the pressure of grain imports, and protecting food security. Owing to data acquisition limitations, obtaining the spatial distribution of reserved arable lands at large spatial scales is relatively rare, and there is little information on predicting the suitability, production capacity, and ecological effects of crop cultivation in reserved arable lands. This study obtained the distribution of reserved arable lands in China by applying restrictive factors, and used the Food and Agriculture Organisation of the United Nations (FAO) suitability index for eight crops to obtain a spatial distribution map of suitable crops, proposed a cropland ecological efficiency index (CEEI) to analyse the ecological impact of crop cultivation in reserved arable lands. RESULTS: China possesses approximately 3.93 million hectares of viable reserved arable lands comprising primarily grasslands (67.68%), sandy land (8.11%), saline-alkali land (20.68%), and bare land (3.53%). The average CEEI for the eight crops under irrigation conditions ranges from 0.844 to 0.865, and that under rain-fed conditions (excluding rice) ranges from 0.609 to 0.779. CONCLUSION: We proposed the development of rain-fed agriculture with sorghum as the primary crop in the central part of Shanxi and Inner Mongolia, while promoting the cultivation of rapeseed and soybeans in the eastern parts of Heilongjiang, Jilin, and Inner Mongolia. Overall, the development of irrigation agriculture focusing on wheat and barley should be pursued only when water resources are guaranteed, particularly in north-western regions such as Gansu, Ningxia, Xinjiang, Qinghai, and Shaanxi. © 2024 Society of Chemical Industry.

Visible-light-driven Oxygen Vacancy and Carbon Doping of C@TiO2-x Photocatalyst for Enhanced Pollutants Degradation Performance.

Oxygen Vacancy (OVs) and carbon doping of the photocatalyst body will significantly enhance the photocatalytic efficiency. However, synchronous regulation of these two aspects is challenging. In this paper, a novel C@TiO2-x photocatalyst was designed by coupling the surface defect and doping engineering of titania, which can effectively remove rhodamine B (RhB) and has a relatively high performance with wide pH range, high photocatalytic activity and good stability. Within 90 minutes, the photocatalytic degradation rate of RhB by C@TiO2-x (94.1 % at 20 mg/L) is 28 times higher than that of pure TiO2 . Free radical trapping experiments and electron spin resonance techniques reveal that superoxide radicals (⋅O2- ) and photogenerated holes (h+ ) play key roles in the photocatalytic degradation of RhB. This study demonstrates the possibility of regulating photocatalysts to degrade pollutants in wastewater based on an integrated strategy.

Recent advances in pulse protein conjugation and complexation with polyphenols: an emerging approach to improve protein functionality and health benefits.

Pulses have attracted much attention in the food industry due to their low cost, high yield, and high protein content, which promises to be excellent alternative protein sources. Recently, techniques for covalent and noncovalent binding of pulse proteins to polyphenols are expected to solve the problem of their poor protein functional properties. Additionally, these conjugates and complexes also show several health benefits. This review summarizes the formation of conjugates and complexes between pulse proteins and polyphenols through covalent and noncovalent binding and the impact of this structural change on protein functionalities and potential health benefits. Recent studies show that pulse protein functionalities can be influenced by polyphenol dose. This is mainly the case for adverse effects on solubility and enhancement in emulsifying capacity. Also, the conjugates/complexes exhibit antioxidant activity and can alter protein digestibility. The antioxidant activity of polyphenols could be retained after binding to proteins, while the effect on digestibility depends on the type or dosage of polyphenols. Considering the link between polyphenols and their potential health benefits, pulse polyphenols would be a good choice for producing the conjugates/complexes due to their low cost and proven potential benefits. Further studies on the structure-function-health benefits relationship of pulse protein-polyphenol conjugates and complexes are still required, as well as the validation of their application as functional foods in the food industry.

Improving the Activity of Tryptophan Synthetase via a Nucleic Acid Scaffold.

Tryptophan synthetase (TSase), which functions as a tetramer, is a typical enzyme with a substrate channel effect, and shows excellent performance in the production of non-standard amino acids, histamine, and other biological derivatives. Based on previous work, we fused a mutant CE protein (colistin of E. coli, a polypeptide with antibacterial activity) sequence with the sequence of TSase to explore whether its catalytic activity could be enhanced, and we also analyzed whether the addition of a DNA scaffold was a feasible strategy. Here, dCE (CE protein without DNase activity) protein tags were constructed and fused to the TrapA and TrapB subunits of TSase, and the whole cell was used for the catalytic reaction. The results showed that after the dCE protein tag was fused to the TrapB subunit, its whole cell catalytic activity increased by 50%. Next, the two subunits were expressed separately, and the proteins were bound in vitro to ensure equimolar combination between the two subunits. After the dCE label was fused to TrapB, the activity of TSase assembled with TrapA also improved. A series of experiments revealed that the enzyme fused with dCE9 showed higher activity than the wild-type protein. In general, the activity of assembly TSase was optimal when the temperature was 50 °C and the pH was about 9.0. After a long temperature treatment, the enzyme maintained good activity. With the addition of exogenous nucleic acid, the activity of the enzyme increased. The maximum yield was 0.58 g/L, which was almost three times that of the wild-type TSase (0.21 g/L). The recombinant TSase constructed in this study with dCE fusion had the advantages of higher heat resistance and higher activity, and confirmed the feasibility of adding a nucleic acid scaffold, providing a new idea for the improvement of structurally similar enzymes.

GSAMDA: a computational model for predicting potential microbe-drug associations based on graph attention network and sparse autoencoder.

BACKGROUND: Clinical studies show that microorganisms are closely related to human health, and the discovery of potential associations between microbes and drugs will facilitate drug research and development. However, at present, few computational methods for predicting microbe-drug associations have been proposed. RESULTS: In this work, we proposed a novel computational model named GSAMDA based on the graph attention network and sparse autoencoder to infer latent microbe-drug associations. In GSAMDA, we first built a heterogeneous network through integrating known microbe-drug associations, microbe similarities and drug similarities. And then, we adopted a GAT-based autoencoder and a sparse autoencoder module respectively to learn topological representations and attribute representations for nodes in the newly constructed heterogeneous network. Finally, based on these two kinds of node representations, we constructed two kinds of feature matrices for microbes and drugs separately, and then, utilized them to calculate possible association scores for microbe-drug pairs. CONCLUSION: A novel computational model is proposed for predicting potential microbe-drug associations based on graph attention network and sparse autoencoder. Compared with other five state-of-the-art competitive methods, the experimental results illustrated that our model can achieve better performance. Moreover, case studies on two categories of representative drugs and microbes further demonstrated the effectiveness of our model as well.

Development and validation of a sensitive and reliable targeted metabolomics method for the quantification of cardiovascular disease-related biomarkers in plasma using ultrahigh-performance liquid chromatography-tandem mass spectrometry.

RATIONALE: Cardiovascular disease, as a multifactorial disease caused by genetics and environment, has emerged as a leading cause of mortality. The discovery of metabolic biomarkers for the clinical diagnosis, early warning and elucidation of the molecular pathogenesis of cardiovascular disease, using metabolomics, has attracted broad interest. Therefore, this work aimed to develop a sensitive and reliable targeted metabolomics method for the quantification of cardiovascular disease-related biomarkers in plasma. METHODS: The method was developed and validated using ultrahigh-performance liquid chromatography augmented with tandem mass spectrometry (UHPLC/MS/MS). The LC conditions and MS parameters were optimized using selected reaction monitoring scanning mode to high-throughput and sensitive separation, and could detect 20 metabolic biomarkers in a single experiment. And the linearity, selectivity, accuracy, precision, stability and recovery of the developed method were assessed according to the Bioanalytical Method Validation guidelines of the United States Food and Drug Administration. RESULTS: These quantified metabolic biomarkers are involved in pathways such as aromatic amino acid catabolism (e.g. phenylalanine, tryptophan, tyrosine), trimethylamine N-oxide (TMAO) biosynthesis (e.g. TMAO, choline, carnitine, betaine) and histidine metabolism (e.g. histidine), among others. All analytes exhibited excellent linearities with coefficients of determination greater than 0.99. Accuracies deviated by less than 15% for medium- and high-concentration samples and less than 20% for low-concentration samples, with intra- and inter-day precisions of 1.12-14.12% and 0.30-13.74%, respectively. Recoveries and stabilities also met the analysis requirements of biological samples. CONCLUSIONS: The targeted metabolomics method was shown to have a powerful ability to accurately analyze metabolic biomarkers, thereby providing valuable information for large-scale biomarker validation and clarifying the potential material basis of cardiovascular disease for clinical diagnosis or early warning.

Immobilized Precursor Particle Driven Growth of Centimeter-Sized MoTe2 Monolayer.

Molybdenum ditelluride (MoTe2) has attracted ever-growing attention in recent years due to its novel characteristics in spintronics and phase-engineering, and an efficient and convenient method to achieve large-area high-quality film is an essential step toward electronic applications. However, the growth of large-area monolayer MoTe2 is challenging. Here, for the first time, we achieve the growth of a centimeter-sized monoclinic MoTe2 monolayer and manifest the mechanism of immobilized precursor particle driven growth. Microscopic characterizations reveal an obvious trend of immobilized precursor particles being consumed by the monolayer and continuing to provide a source for the growth of the monolayer. Time-of-flight secondary ion mass spectrometry verifies the attachment of hydroxide ions on the surface of the MoTe2 monolayer, thereby realizing the inhibition of crystal growth along the [001] zone axis and the continuous growth of the MoTe2 monolayer. The first-principles DFT calculations prove the mechanism of immobilized precursor particles and the absorption of hydroxide ions on the MoTe2 monolayer. The as-grown MoTe2 monolayer exhibits a surface roughness of 0.19 nm and average conductivity of 1.5 × 10-5 S/m, which prove the smoothness and uniformity of the MoTe2 monolayer. Temperature-dependent electrical measurements together with the transfer characteristic curves further demonstrate the typical semimetallic properties of monoclinic MoTe2. Our research elaborates the microscopic process of immobilized precursor particles to grow large-area MoTe2 monolayer and provides a new thinking about the growth of many other two-dimensional materials.

Sub-Nanometer Thick Wafer-Size NiO Films with Room-Temperature Ferromagnetic Behavior.

Adding ferromagnetism into semiconductors attracts much attentions due to its potential usage of magnetic spins in novel devices, such as spin field-effect transistors. However, it remains challenging to stabilize their ferromagnetism above room temperature. Here we introduce an atomic chemical-solution strategy to grow wafer-size NiO thin films with controllable thickness down to sub-nanometer scale (0.92 nm) for the first time. Surface lattice defects break the magnetic symmetry of NiO and produce surface ferromagnetic behaviors. Our sub-nanometric NiO thin film exhibits the highest reported room-temperature ferromagnetic behavior with a saturation magnetization of 157 emu/cc and coercivity of 418 Oe. Attributed to wafer size, the easily-transferred NiO thin film is further verified in a magnetoresistance device. Our work provides a sub-nanometric platform to produce wafer-size ferromagnetic NiO thin films as atomic layer magnetic units in future transparent magnetoelectric devices.

Agro-ecological suitability assessment of Chinese Medicinal Yam under future climate change.

Chinese Medicinal Yam (CMY) has been prescribed as medicinal food for thousand years in China by Traditional Chinese Medicine (TCM) practitioners. Its medical benefits include nourishing the stomach and spleen to improve digestion, replenishing lung and kidney, etc., according to the TCM literature. As living standard rises and public health awareness improves in recent years, the potential medicinal benefits of CMY have attracted increasing attention in China. It has been found that the observed climate change in last several decades, together with the change in economic structure, has driven significant shift in the pattern of the traditional CMY planting areas. To identify suitable planting area for CMY in the near future is critical for ensuring the quality and supply quantity of CMY, guiding the layout of CMY industry, and safeguarding the sustainable development of CMY resources for public health. In this study, we first collect 30-year records of CMY varieties and their corresponding phenology and agro-meteorological observations. We then consolidate these data and use them to enrich and update the eco-physiological parameters of CMY in the agro-ecological zone (AEZ) model. The updated CMY varieties and AEZ model are validated using the historical planting area and production under observed climate conditions. After the successful validation, we use the updated AEZ model to simulate the potential yield of CMY and identify the suitable planting regions under future climate projections in China. This study shows that regions with high ecological similarity to the genuine and core producing areas of CMY mainly distribute in eastern Henan, southeastern Hebei, and western Shandong. The climate suitability of these areas will be improved due to global warming in the next 50 years, and therefore, they will continue to be the most suitable CMY planting regions.

CDK6 inhibits lymphoid cell infiltration and represents a prognostic marker in HPV+ squamous cell carcinoma of head and neck.

OBJECTIVE: We investigated the correlations between cyclin-dependent kinase 4/6 (CDK4/6) levels and human papillomavirus (HPV) infection state in head and neck squamous cell cancer (HNSCC). The aim was to explore the potential value of CDK4/6 inhibitors in the treatment of HNSCC. METHODS: Multiomic sequencing data for HNSCC were obtained from The Cancer Genome Atlas (TCGA), and the mRNA levels and copy number variations (CNVs) of CDK4 and CDK6 were strictly analyzed. Overall survival (OS) curves were produced using the Kaplan-Meier method, and survival differences between groups were assessed by the log-rank test. Next, gene set enrichment analysis (GSEA) was applied to interrogate CDK4/6-associated molecular pathways in HPV-positive (HPV+) and HPV-negative (HPV-) HNSCC. Last, lymphoid cell infiltrates in each type of HNSCC were explored, and the correlations between CDK4/6 expression and lymphoid infiltrates were explored by Tumor Immune Estimation Resource (TIMER) analysis. RESULTS: Overexpression of either CDK6 or CDK4 was not a relevant factor for OS in HPV- HNSCC (CDK6: top 40%vs. bottom 40%, P=0.885; CDK4: top 40% vs. bottom 40%, P=0.267). In HPV+ HNSCC, CDK6 but not CDK4 was a relevant factor for OS (CDK6: top 40% vs. bottom 40%, P=0.002; CDK4: top 40% vs. bottom 40%, P=0.452). GSEA found that overexpressed CDK6 in HPV+ HNSCC inhibited pathways involved in the tumor immune response, suggesting its roles in antitumor immunity. TIMER analysis results revealed that CDK6 but not CDK4 accumulation was negatively correlated with the number of tumor-infiltrating lymphocytes specific for HPV+ HNSCC, which led to tumor response suppression. CONCLUSIONS: CDK6, but not CDK4, is a poor prognostic marker specific in HPV+ HNSCC patients. Overexpressed CDK6 might stimulate tumor progression by suppressing lymphocytes infiltration independent of its kinase activity. Only abrogating its kinase activity using current CDK4/6 inhibitors was not enough to block its tumor promotion function.

Microalgal proteins: Unveiling sustainable alternatives to address the protein challenge.

Recent breakthroughs emphasized the considerable potential of microalgae as a sustainable protein source. Microalgae are regarded as a substitute for protein-rich foods because of their high protein and amino acid content. However, despite their nutritional value, microalgae cannot be easily digested by humans due to the presence of cell walls. In the subsequent sections, protein extraction technology, the overview of the inherent challenges of the process, and the summary of the factors affecting protein extraction and utilization have been deliberated. Moreover, the review inspected the formation of proteolytic products, highlighting their diverse bioactivities, including antioxidant, antihypertensive, and immunomodulatory activities. Finally, the discussion extended to the emerging microalgal protein sourced foods, such as baked goods and nutritional supplements, as well as the sensory and marketing challenges encountered in the production of microalgal protein foods. The lack of consumer awareness about the health benefits of microalgae complicates its acceptance in the market. Long-standing challenges, such as high production costs, persist. Currently, multi-product utilization strategies are being developed to improve the economic viability of microalgae. By integrating economic, environmental, and social factors, microalgae protein can be sustainably developed to provide a reliable source of raw materials for the future food industry.

Role of inflammatory cytokine in mediating the effect of plasma lipidome on epilepsy: a mediation Mendelian randomization study.

Background: Epilepsy is one of the most prevalent serious brain disorders globally, impacting over 70 million individuals. Observational studies have increasingly recognized the impact of plasma lipidome on epilepsy. However, establishing a direct causal link between plasma lipidome and epilepsy remains elusive due to inherent confounders and the complexities of reverse causality. This study aims to investigate the causal relationship between specific plasma lipidome and epilepsy, along with their intermediary mediators. Methods: We conducted a two-sample Mendelian randomization (MR) and mediation MR analysis to evaluate the causal effects of 179 plasma lipidomes and epilepsy, with a focus on the inflammatory cytokine as a potential mediator based on the genome-wide association study. The primary methodological approach utilized inverse variance weighting, complemented by a range of other estimators. A set of sensitivity analyses, including Cochran's Q test, I 2 statistics, MR-Egger intercept test, MR-PRESSO global test and leave-one-out sensitivity analyses was performed to assess the robustness, heterogeneity and horizontal pleiotropy of results. Results: Our findings revealed a positive correlation between Phosphatidylcholine (18:1_18:1) levels with epilepsy risk (OR = 1.105, 95% CI: 1.036-1.178, p = 0.002). Notably, our mediation MR results propose Tumor necrosis factor ligand superfamily member 12 levels (TNFSF12) as a mediator of the relationship between Phosphatidylcholine (18,1_18:1) levels and epilepsy risk, explaining a mediation proportion of 4.58% [mediation effect: (b = 0.00455, 95% CI: -0.00120-0.01030), Z = 1.552]. Conclusion: Our research confirms a genetic causal relationship between Phosphatidylcholine (18:1_18:1) levels and epilepsy, emphasizing the potential mediating role of TNFSF12 and provide valuable insights for future clinical investigations into epilepsy.

Monomolecular Membrane-Assisted Growth of Antimony Halide Perovskite/MoS2 Van der Waals Epitaxial Heterojunctions with Long-Lived Interlayer Exciton.

Epitaxial growth stands as a key method for integrating semiconductors into heterostructures, offering a potent avenue to explore the electronic and optoelectronic characteristics of cutting-edge materials, such as transition metal dichalcogenide (TMD) and perovskites. Nevertheless, the layer-by-layer growth atop TMD materials confronts a substantial energy barrier, impeding the adsorption and nucleation of perovskite atoms on the 2D surface. Here, we epitaxially grown an inorganic lead-free perovskite on TMD and formed van der Waals (vdW) heterojunctions. Our work employs a monomolecular membrane-assisted growth strategy that reduces the contact angle and simultaneously diminishing the energy barrier for Cs3Sb2Br9 surface nucleation. By controlling the nucleation temperature, we achieved a reduction in the thickness of the Cs3Sb2Br9 epitaxial layer from 30 to approximately 4 nm. In the realm of inorganic lead-free perovskite and TMD heterojunctions, we observed long-lived interlayer exciton of 9.9 ns, approximately 36 times longer than the intralayer exciton lifetime, which benefited from the excellent interlayer coupling brought by direct epitaxial growth. Our research introduces a monomolecular membrane-assisted growth strategy that expands the diversity of materials attainable through vdW epitaxial growth, potentially contributing to future applications in optoelectronics involving heterojunctions.

A novel HOIP frameshift variant alleviates NF-kappaB signalling and sensitizes cells to TNF-induced death.

BACKGROUND: HOIP is the catalytic subunit of the E3 ligase complex (linear ubiquitin chain assembly complex), which is able to generate linear ubiquitin chains. However, the role of rare HOIP functionally deficient variants remains unclear. The pathogenic mechanism and the relationship with immune deficiency phenotypes remain to be clarified. METHODS: Based on a next-generation sequencing panel of 270 genes, we identified a HOIP deletion variant that causes common variable immunodeficiency disease. Bioinformatics analysis and cell-based experiments were performed to study the molecular mechanism by which the variant causes immunodeficiency diseases. FINDINGS: A homozygous loss-of-function variant in HOIP was identified. The variant causes a frameshift and generates a premature termination codon in messenger RNA, resulting in a C-terminal truncated HOIP mutant, that is, the loss of the linear ubiquitin chain-specific catalytic domain. The truncated HOIP mutant has impaired E3 ligase function in linear ubiquitination, leading to the suppression of canonical NF-κB signalling and increased TNF-induced multiple forms of cell death. INTERPRETATION: The loss-of-function HOIP variant accounts for the immune deficiencies. The canonical NF-κB pathway and cell death are involved in the pathogenesis of the disease. FUNDING: This study was funded by the National Natural Science Foundation of China (No. 82270444 and 81501851). RESEARCH IN CONTEXT: Evidence before this study LUBAC is the only known linear ubiquitin chain assembly complex for which HOIP is an essential catalytic subunit. Three HOIP variants have now been identified in two immunodeficient patients and functionally characterised. However, there have been no reports on the pathogenicity of only catalytic domain deletion variants in humans, or the pathogenic mechanisms of catalytic domain deletion variants. Added value of this study We report the first case of an autosomal recessive homozygous deletion variant that results in deletion of the HOIP catalytic structural domain. We demonstrate that this variant is a loss-of-function variant using a heterologous expression system. The variant has impaired E3 ligase function. It can still bind to other subunits of LUBAC, but it fails to generate linear ubiquitin chains. We also explored the underlying mechanisms by which this variant leads to immunodeficiency. The variant attenuates the canonical NF-κB and MAPK signalling cascades and increases the sensitivity of TNFα-induced diverse cell death and activation of mitochondrial apoptosis pathways. These findings provide support for the treatment and drug development of patients with inborn errors of immunity in HOIP and related signalling pathways. Implications of all the available evidence First, this study expands the HOIP pathogenic variant database and phenotypic spectrum. Furthermore, studies on the biological functions of pathogenic variants in relation to the NF-κB signalling pathway and cell death provided new understanding into the genetic basis and pathogenesis of HOIP-deficient immune disease, indicating the necessity of HOIP and related signalling pathway variants as diagnostic targets in patients with similar genetic deficiency phenotypes..

Research progress of multi-enzyme complexes based on the design of scaffold protein.

Multi-enzyme complexes designed based on scaffold proteins are a current topic in molecular enzyme engineering. They have been gradually applied to increase the production of enzyme cascades, thereby achieving effective biosynthetic pathways. This paper reviews the recent progress in the design strategy and application of multi-enzyme complexes. First, the metabolic channels in the multi-enzyme complex have been introduced, and the construction strategies of the multi-enzyme complex emerging in recent years have been summarized. Then, the discovered enzyme cascades related to scaffold proteins are discussed, emphasizing on the influence of the linker on the fusion enzyme (fusion protein) and its possible mechanism. This review is expected to provide a more theoretical basis for the modification of multi-enzyme complexes and broaden their applications in synthetic biology.