Bioconversion of agriculture by-products with functionally enhanced Streptomyces sp. SCUT-3: Fish skin as a model.

With the global population continuously rising, efficient bioconversion of inedible agricultural by-products is crucial for human food and energy sustainability. We here propose solid-state fermentation approaches to efficiently convert biopolymers into oligomers/monomers by accelerating the natural degradation process of the versatile Streptomyces sp. strain SCUT-3. Using fish skin as a representative by-product, 54.3 g amino acids and 14.7 g peptides (91 % < 2500 Da) were recovered from 89.0 g protein in 100 g tilapia skin sample by collagenase-overexpressed SCUT-3 for seven days at a 1:4 substrate:liquid ratio. Fish skin collagen hydrolysates exhibited excellent anti-oxidation, anti-hypertension, scratch-repairing, anti-aging, anti-ultraviolet radiation, and anti-inflammation effects on human skin fibroblasts In vitro and zebrafish larvae in vivo, indicating their potential applications in healthcare/skincare and anti-atopic dermatitis. As Laozi said, the divine law follows nature. This study underscores the efficacy of genetically engineered SCUT-3 according to its natural biomass utilization laws in large-scale biopolymer conversion.

Meta-Analysis of Collaborative Inhibition Moderation by Gender, Membership, Culture, and Memory Monitoring.

Collaborative inhibition is a counterintuitive phenomenon. While the specific mechanisms through which social factors influence collaborative inhibition remain unclear, this study aims to shed light on the impact of gender, relationships, and culture in order to better understand the factors shaping collaborative inhibition. A meta-analysis was conducted to analyze subgroups of social factors, including collaborative pairing, gender, membership, and culture, as well as cognitive factors like memory monitoring. Collaborative inhibition was found to be a robust effect (p < 0.01), with moderating effects of pairing on gender (p < 0.01), membership (p < 0.01), culture (p < 0.01), and memory monitoring (p < 0.01). The findings indicate that collaborative inhibition is a consistent phenomenon influenced by both social and cognitive factors. Moreover, the study discovered that memory monitoring can successfully moderate collaborative inhibition, although the underlying mechanism requires further investigation.

The improvement strategy of fresh produce supply chain resilience based on extenics.

Nowadays, the world is in turmoil, climate and environmental problems are prominent, the import and export of fresh agricultural products are restricted, etc. The impact of the growing demand for fresh agricultural products and healthy lifestyle choices, and fresh agricultural products are essential for people's daily life, which are perishable, fragile, seasonal, and other unstable factors. Therefore, when the fresh produce supply chain faces various pressures and difficulties, how to enhance the resilience of the supply chain against various problems and risks with flexible and multi-dimensional strategies and methods has become the focus of extensive attention. This kind of problem is a typical contradictory problem, and previous studies have failed to achieve good results. In this paper, based on extenics, we are able to one-dimensionalise the multi-dimensional contradictory problems and multi-dimensionalise the one-dimensional contradictory problems to solve such problems in a scientific and effective way. Firstly, taking fresh agricultural products supply chain enterprise M as the research object, we constructed the fresh agricultural products supply chain enterprise toughness system and identified the toughness state of each index. Secondly, we found the low-evaluation toughness indexes that need to be solved and constructed a extension model of incompatible problems of enterprise toughness. Thirdly, we analysed the objectives and conditions of toughness incompatible problems of fresh agricultural products supply chain enterprises numerically and quantitatively, and then, with the objective of toughness improvement, we analyzed the correlation of the condition basic-elements of incompatible problems and carried out extension transformations. Again, the objectives and conditions of the incompatible problems of fresh produce supply chain enterprises are analysed numerically and quantitatively, and with toughness enhancement as the objective, the correlation analysis and extension transformation of the condition basic-elements of the incompatible problems are implemented to generate the set of toughness enhancement strategies that can solve the incompatible problems in a multidimensional and scientific way. Finally, the optimal toughness enhancement strategies are selected through the superiority evaluation and composed into a new strategy to enhance the toughness of the fresh produce supply chain. Combined with extenics calculations and screening, a new strategy for supply chain resilience enhancement of fresh agricultural products was finally formed. The existing problems are solved from six aspects: product supply type, product demand, product supply efficiency, human resource quantity, production and processing equipment, and logistics guarantee ability. It provides a certain reference significance for the fresh agricultural products supply chain toughness enhancement, and helps enterprises to strengthen their competitiveness and sustainability through the enhancement of toughness.

Resilience evaluation of low-carbon supply chain based on improved matter-element extension model.

How to evaluate the resilience level and change trend of supply chain is an important research direction in current supply chain management practice. This paper proposes a new method of supply chain resilience assessment based on hesitant fuzzy linguistic term set (HFLTS) and matter element extension theory. Firstly, based on the research status quo at home and abroad, a low-carbon enterprise supply chain resilience assessment index system is established, which includes six first-level indicators and corresponding 21 second-level indicators of product supply resilience, resource resilience, partner resilience, information response resilience, financial resilience and knowledge resilience. Secondly, HFLTS was used to collect expert opinions and Ordered Weighted Arithmetic (OWA) to calculate the expert composite language, by which the fuzzy evaluation matrix of supply chain resilience assessment indicators was obtained. Once again, the resilience indicator weights are determined based on a game-theoretic portfolio assignment method combining the best-worst method (BWM) and the CRITIC method. Finally, the nearness degree function is combined with the extension comprehensive evaluation method to improve the matter element extension model, and the supply chain resilience assessment model of low-carbon enterprises based on the game theory combination assignment-improved matter element extension is established. Taking X low-carbon enterprise as an example, the evaluation results show that the supply chain resilience level of this enterprise is II, and the eigenvalue of the grade variable is 2.69, and the supply chain resilience is shifting to III, and the supply chain resilience is shifting to III, which indicates that the supply chain resilience of this enterprise is being enhanced. Therefore, the improved matter element extension not only ensures the accuracy of the evaluation results, but also has higher prediction accuracy.

Sustainable valorizing high-protein feather waste utilization through solid-state fermentation by keratinase-enhanced Streptomyces sp. SCUT-3 using a novel promoter.

Feather waste, a rich source of proteins, has traditionally been processed through high-temperature puffing and acid-base hydrolysis, contributing to generation of greenhouse gases and H2S. To address this issue, we employed circular economy techniques to recover the nutritional value of feather waste. Streptomyces sp. SCUT-3, an efficient proteolytic and chitinolytic bacterium, was isolated for feather degradation previously. This study aimed to valorize feather waste for feed purposes by enhancing its feather transformation ability through promoter optimization. Seven promoters were identified through omics analysis and compared to a common Streptomyces promoter ermE*p. The strongest promoter, p24880, effectively enhanced the expression of three candidate keratinases (Sep39, Sep40, and Sep53). The expression efficiency of double-, triple-p24880 and sandwich p24880-sep39-p24880 promoters were further verified. The co-overexpression strain SCUT-3-p24880-sep39-p24880-sep40 exhibited a 16.21-fold increase in keratinase activity compared to the wild-type. Using this strain, a solid-state fermentation process was established that increased the feather/water ratio (w/w) to 1:1.5, shortened the fermentation time to 2.5 days, and increased soluble peptide and free amino acid yields to 0.41 g/g and 0.14 g/g, respectively. The resulting has high protein content (90.49 %), with high in vitro digestibility (94.20 %). This method has the potential to revolutionize the feather waste processing industry.

Highway Visibility Estimation in Foggy Weather via Multi-Scale Fusion Network.

Poor visibility has a significant impact on road safety and can even lead to traffic accidents. The traditional means of visibility monitoring no longer meet the current needs in terms of temporal and spatial accuracy. In this work, we propose a novel deep network architecture for estimating the visibility directly from highway surveillance images. Specifically, we employ several image feature extraction methods to extract detailed structural, spectral, and scene depth features from the images. Next, we design a multi-scale fusion network to adaptively extract and fuse vital features for the purpose of estimating visibility. Furthermore, we create a real-scene dataset for model learning and performance evaluation. Our experiments demonstrate the superiority of our proposed method to the existing methods.

Identification and formation mechanism of key elements of supply chain resilience: Exploration based on grounded theory and verification of SEM.

Supply chain resilience has garnered significant attention from both scholars and practitioners. However, the complex nature of the topic has resulted in a dearth of research on its key elements and formation mechanisms. To bridge this knowledge gap, we implemented grounded theory and conducted semi-structured interviews with 23 interviewees, which led to the identification of six key elements of supply chain resilience through open coding, axial coding, selective coding, and theoretical model saturation testing. These elements are product supply resilience, resource resilience, partner resilience, information response resilience, capital resilience, and knowledge resilience. Drawing from the key elements and the three phases of supply chain resilience (readiness, response, and recovery), we illustrated its formation mechanism and constructed a theoretical model of the influencing factors and pathways of supply chain resilience. We devised a questionnaire based on the coding results and confirmed its reasonableness and validity with a small sample of 109 questionnaires. Subsequently, a large sample of 409 questionnaires was used to test and validate the theoretical model using structural equation modeling, demonstrating that the identified key elements positively impact supply chain resilience. In sum, our paper enriches the comprehension of supply chain resilience by identifying its key elements and elaborating on its formation mechanism.

Sustainable supplier selection based on VIKOR with single-valued neutrosophic sets.

Considering economic, environmental, and social issues, the sustainability of the supply chain has drawn considerable attention due to societal and environmental changes within the supply chain network. The strategic study of the entire supply chain process and maximizing an organization's competitive advantage depend heavily on supplier selection based on sustainable indicators. Selecting sustainable suppliers for the supply chain is challenging since it is a multi-criteria decision-making (MCDM) problem with significant uncertainty in the decision-making process. This study uses the VlseKriterijumska Optimizacija I Kompromisno Resenje (VIKOR) technique and single-valued neutrosophic sets (SVNS) to deal with the challenge of choosing a sustainable supplier with insufficient information. This method reduces the influence of personal experience and preference on the final evaluation results and the problem of excessive individual regret caused by factor correlation and improves the consistency of evaluation results. Finally, the method's success and adaptability are demonstrated by sensitivity analysis and additional comparison analysis, and the benefits and drawbacks of the suggested framework are examined. Compared to other approaches, it can assist decision-makers in communicating fuzzy and uncertain information, offering a perspective and approach for MCDM in the face of such situations, and helping them select suppliers of high caliber and who practice sustainable business practices.

Degradation of indole via a two-component indole oxygenase system from Enterococcus hirae GDIAS-5.

Animal farming copiously generates indoles, which contribute to odor and pose a challenge for deodorization. While biodegradation is widely accepted, there is a lack of suitable indole-degrading bacteria for animal husbandry. In this study, we aimed to construct genetically engineered strains with indole-degrading abilities. Enterococcus hirae GDIAS-5 is a highly efficient indole-degrading bacterium, which functions via a monooxygenase YcnE presumably contributes to indole oxidation. However, the efficiency of engineered Escherichia coli expressing YcnE for indole degradation is lower than that of GDIAS-5. To improve its efficacy, the underlying indole-degradation mechanisms in GDIAS-5 were analyzed. An ido operon that responds to a two-component indole oxygenase system was identified. In vitro experiments showed that the reductase component of YcnE, YdgI, can improve the catalytic efficiency. The reconstruction of the two-component system in E. coli exhibited higher indole removal efficiency than GDIAS-5. Furthermore, isatin, the key intermediate metabolite in indole degradation, might be degraded via a novel isatin-acetaminophen-aminophenol pathway involving an amidase whose coding gene is located near the ido operon. The two-component anaerobic oxidation system, upstream degradation pathway, and engineering strains investigated in this study provide important insights into indole degradation metabolism and offer efficient resources for achieving bacterial odor elimination.

Green transition in manufacturing: Dynamics and simulation.

Under the dual background of global industrial value chain and low-carbon emission reduction, the green transformation and upgrading of the manufacturing industry is an important way to promote production and promote sustainable economic development. Considering that the green transformation of the manufacturing industry is a typical complex adaptation system, based on the intrinsic relationship between the dynamic theory and the green transformation of the manufacturing industry, this paper takes the endogenous variable of the transformation of manufacturing enterprises as the entry point, simulates the transformation of new and old dynamic energy of green transformation, and explores the mechanism of green transformation and upgrading of manufacturing industry and the conversion process. According to the model, it is concluded that the green transformation of manufacturing enterprises is the result of the multi-stage transformation of enterprises. In this process, the change inertia overcomes old dynamic inertia and promotes the new dynamic to gradually replace the old dynamic. At the end of the article, specific suggestions are given to promote the green transformation of manufacturing enterprises from the aspects of ideology, policy support, digital empowerment, financial service guarantee system and communication and cooperation.

Synergic chitin degradation by Streptomyces sp. SCUT-3 chitinases and their applications in chitinous waste recycling and pathogenic fungi biocontrol.

The genus Streptomyces comprises the most important chitin decomposers in soil and revealing their chitinolytic machinery is beneficial for the conversion of chitinous wastes. Streptomyces sp. SCUT-3, a chitin-hydrolyzing and a robust feather-degrading bacterium, was isolated previously. The potential chitin-degrading enzymes produced by SCUT-3 were analyzed in the present study. Among these enzymes, three chitinases were successfully expressed in Pichia pastoris at comparatively high yields of 4.8 U/mL (SsExoChi18A), 11.2 U/mL (SsExoChi18B), and 17.8 U/mL (SsEndoChi19). Conserved motifs and constructive 3D structures of these three exo- and endochitinases were also analyzed. These chitinases hydrolyzed colloidal chitin to chitin oligomers. SsExoChi18A showed apparent synergic effects with SsEndoChi19 in colloidal chitin and shrimp shell hydrolysis, with an improvement of 29.3 % and 124.9 %, respectively. Compared with SsExoChi18B and SsEndoChi19, SsExoChi18A exhibited the strongest antifungal effects against four plant pathogens by inhibiting mycelial growth and spore germination. This study provided good candidates for chitinous waste-processing enzymes and antifungal biocontrol agents. These synergic chitin-degrading enzymes of SCUT-3 are good targets for its further genetical modification to construct super chitinous waste-degrading bacteria with strong abilities to hydrolyze both protein and chitin, thereby providing a direction for the future path of the chitinous waste recycling industry.

Intelligent selection of healthcare supply chain mode - an applied research based on artificial intelligence.

Introduction: Due to the inefficiency and high cost of the current healthcare supply chain mode, in order to adapt to the great changes in the global economy and public health, it is urgent to choose an effective mode for sustainable development of healthcare supply chain. The aim of this paper is to use artificial intelligence systems to make intelligent decisions for healthcare supply chain mode selection. Methods: Firstly, according to the economic benefits, social benefits and environmental benefits of healthcare supply chain, this paper identifies different healthcare supply chain modes in combination with artificial intelligence technology. Secondly, this paper presents the intelligent choice optimization method of healthcare supply chain mode based on deep reinforcement learning algorithm. Finally, the effect of artificial intelligence in healthcare supply chain mode selection is verified by simulation experiment. Results and Discussion: The experimental results show that healthcare supply chain mode selected by artificial intelligence is basically consistent with the target mode, while healthcare supply chain mode selected by the basic selection method, BP neural network method and big data method is different from the target mode, which indicates that AI has more advantages in the selection of medical supply chain mode. Therefore, we recommend the application of artificial intelligence to healthcare supply chain management. This study not only makes up for the ineffective problems of existing methods, but also makes up for the gaps in the application of AI technology in the field of healthcare supply chain. The scientific value of this paper is that the proposed framework and the artificial intelligence algorithm enrich the relevant theories of healthcare supply chain research and provide methodological guidance for intelligent decision-making of healthcare supply chain. At the same time, for medical enterprises, this research provides a new practical guideline for the application of artificial intelligence in the sustainable development and modern management of healthcare supply chain.

Effects of Tegafur, Gimeracil and Oteracil Potassium Capsules combined with Calf Spleen Extractive Injection on serum VEGF and MMP-9 in patients with advanced gastric cancer.

OBJECTIVE: To explore the effects of Tegafur, Gimeracil and Oteracil Potassium Capsules (TGOPC) combined with Calf Spleen Extractive Injection (CSEI) on vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP-9) in patients with advanced gastric cancer. METHODS: A retrospective analysis was conducted on data of 118 patients with advanced gastric cancer treated in Anyang Tumor Hospital from January 2016 to September 2018. The patients were divided into two groups according to treatment modalities, with control group receiving Oxaliplatin and TGOPC and observation group receiving Oxaliplatin, TGOPC and CSEI. Clinical efficacy, changes of serum VEGF and MMP-9 before and after chemotherapy, survival rate and incidence of adverse reactions were compared between the two groups. RESULTS: The number of responded patients was 36 (61.02%) in the observation group and was 18 (30.51%) in the control group (P<0.05). The levels of serum VEGF and MMP-9, and incidence of nausea and vomiting in the observation group were lower than those in the control group (P<0.05). The 1-year and 2-year survival rates in the observation group were higher than those in the control group (P<0.05). CONCLUSION: The use of CSEI on the basis of Oxaliplatin combined with TGOPC chemotherapy for the treatment of advanced gastric cancer could further improve the clinical efficacy and survival rate, and reduce the incidence of adverse reactions.

Indole metabolism mechanisms in a new, efficient indole-degrading facultative anaerobe isolate Enterococcus hirae GDIAS-5.

Indole is an inter-species and inter-kingdom signaling molecule widespread in the natural world. A large amount of indole in livestock wastes makes it difficult to be degraded, which causes serious malodor. Identifying efficient and eco-friendly ways to eliminate it is an urgent task for the sustainable development of husbandry. While bioconversion is a widely accepted means, the mechanism of indole microbial degradation is little understood, especially under anaerobic conditions. Herein, a new Enterococcus hirae isolate GDIAS-5, effectively degraded 100 mg/L indole within 28 h aerobically or 5 days anaerobically. Three intermediates (oxindole, isatin, and catechol) were identified in indole degradation, and catechol was further degraded by a meta-cleavage catabolic pathway. Two important processes for GDIAS-5 indole utilization were discovered. One is Fe(III) uptake and reduction, which may be a critical process that is coupled with indole oxidation, and the other is the entire pathway directly involved in indole oxidation and metabolism. Furthermore, monooxygenase ycnE responsible for indole oxidation via the indole-oxindole-isatin pathway was identified for the first time. Bioinformatic analyses showed that ycnE from E. hirae formed a phylogenetically separate branch from monooxygenases of other species. These findings provide new targets and strategies for synthetic biological reconstruction of indole-degrading bacteria.

Transcriptomic analysis reveals innate immune mechanisms of an underlying parasite-resistant grouper hybrid (Epinephelus fuscogutatus × Epinephelus lanceolatus).

Hybridization is an artificial breeding strategy for generating potentially desirable offspring. Recently, a novel Hulong grouper hybrid (Epinephelus fuscogutatus × Epinephelus lanceolatus) yielded significant growth superiority over its parent. Improved innate immunity is considered as another desirable feature during hybridization. However, whether this Hulong grouper achieved disease resistance has not yet been revealed. In this study, we first examine the infection intensity of C. irritans in the Hulong grouper, and found that the Hulong grouper is less susceptible to C. irritans primary infection. A higher immobilization titer was found in the infected Hulong grouper at Day 2 when compared with the control grouper. Furthermore, severe hyperplasia was observed in the orange-spotted grouper, but not in the Hulong grouper's skin epidermis. To further understand the innate immune mechanism against C. irritans, we conducted a comparative transcriptome analysis of the Hulong grouper during the infection. There are 6464 differentially expressed genes (DEGs) identified in the skin between the control and infected Hulong grouper. This indicates that the innate immune components, such as the complement system, nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, Interleukin 17 (IL-17) signaling pathway, and Toll-like receptor (TLR) signaling pathway were up-regulated during the infection. These results show that the C. irritans infection can induce a remarkable inflammatory response in the Hulong grouper. Moreover, a total of 75 pairs of orthologs with the ratio of nonsynonymous (Ka) to synonymous (Ks) substitutions ＞1, considered rapidly evolving genes (REGs), was identified between the Hulong and orange-spotted grouper. More critically, most REGs were enriched in the immune system, suggesting that rapid evolution of the immune system might occur in the Hulong grouper. These results provide a more comprehensive understanding of the innate immunity mechanism of the hybrid Hulong grouper.

Study on the characterization of grouper (Epinephelus coioides) immunoglobulin T and its positive cells.

Immunoglobulins (Igs) play a vital role in the adaptive immunity of gnathostomes. IgT, a particular Ig class in teleost fishes, receives much attention concerning the mucosal immunity. While, the characteristic and function of Epinephelus coioides IgT is still unknown. In our study, a polyclonal antibody was first prepared with grouper IgT heavy chain recombinant protein. IgT was revealed to be polymeric in serum and mucus. In normal groupers, IgT had high expression level in head kidney and spleen, while little amount in gills, thymus, gut and liver. The number of IgT-positive cells in different tissues was in line with their IgT expression. Furthermore, IgT could coat fractional bacteria in the mucus. In conclusion, this research revealed the protein characteristic, basal expression and bacterial coverage of grouper IgT. This is the first study to identify the characteristic of grouper IgT and demonstrate the capacity of coating microbes.

Investigating the Critical Factors of Professionals' BIM Adoption Behavior Based on the Theory of Planned Behavior.

In recent years, building information modeling (BIM) has been receiving growing interest from the construction industry of China. Nevertheless, although BIM has many foreseeable advantages, many studies claimed that these advantages have not been sufficiently achieved in practice at the current stage. In this circumstance, it is interesting to investigate what really drives the adoption of BIM. Based on Ajzen's theory of planned behavior (TPB), a hypothetical model which involves nine latent variables is initially established. Then, a questionnaire is designed and distributed to the construction professionals in the Chinese context. After reliability and validity analysis, the goodness-of-fit of the initial model and the related theoretical assumptions are tested through structural equation modeling (SEM). Based on the modification indicators, a modified model is finally derived. Results show that economic viability and governmental supervision are the most critical factors that influence construction professionals' BIM adoption behavior in China, sharing weights of 0.37 and 0.34, respectively, whereas other factors play limited roles in this regard. The research findings revealed from this study can provide insightful references for countries that intend to promote BIM adoption in a similar circumstance.

Characterization and functional analysis of hybrid pearl gentian grouper (Epinephelus lanceolatus♂ × Epinephelus fuscoguttatus♀) complement C3 against Cryptocaryon irritans infection.

Pearl gentian grouper is a new aquacultural hybrid resulted from breeding of female tiger grouper (Epinephelus fuscogutattus) and male giant grouper (E. lanceolatus). Our preliminary study found that pearl gentian grouper exhibits less susceptible to the primary infection of Cryptocaryon irritans, which is an important parasitic ciliate in marine aquaculture, indicated that pearl gentian grouper might own a strong innate immune system. Complement system play key roles in innate immunity, whether pearl gentian grouper's complement component contribute for the defensing against the C. irritans infection remain unclear. In the present study, we found that C. irritans can be immobilized by untreated serum but not heat-treated serum from pearl gentian grouper, suggested that the heat-labile components in serum are responsible for the immobilization of C. irritans. Moreover, we cloned and characterized the encoding sequence of pearl gentian grouper complement C3 (PGC3), a key component in complement system. We also found that the expression level of PGC3 was increased in infected grouper serum when compared with that of control grouper. Furthermore, the binding of PGC3 on the surface of C. irritans trophonts located on the grouper skin was detected. These data suggested that pearl gentian grouper's complement system indeed play roles in the immune response against the C. irritans infection.

Role of major histocompatibility complex II antigen-presentation pathway genes in orange-spotted grouper infected with Cryptocaryon irritans.

Cryptocaryon irritans, a pathogen model for fish mucosal immunity, causes skin mucosal and systematic humoral immune response. Where and how MHC II antigen presentation occurs in fish infected with C. irritans remain unknown. In this study, the full-length cDNA of the grouper cysteine protease CTSS was cloned. The expression distributions of six genes (CTSB, CTSL, CTSS, GILT, MHC IIA and MHC IIB) involved in MHC II antigen presentation pathway were tested. These genes were highly expressed in systematic immune tissues and skin and gill mucosal-associated immune tissues. All six genes were upregulated in skin at most time points. Five genes expected CTSS was upregulated in spleen at most time points. CTSB, CTSL and MHC IIA were upregulated in the gill and head kidney at some time points. These results indicate that the presentation of MHC II antigen intensively occurred in local infected skin and gill. Spleen, not head kidney, had the most extensive systematic antigen presentation. In skin, six genes most likely peaked at day 2, earlier than in spleen (5-7 days), marking an earlier skin antibody peak than any recorded in serum previously. This significant and earlier mucosal antigen presentation indicates that specific immune response occurs in local mucosal tissues.

Grouper (Epinephelus coioides) IRAK-4 regulates activation of NF-κB and expression of inflammatory cytokines in grouper spleen cells.

IRAK-4 is a serine/threonine kinase that can bind to interleukin-1 receptor induced by interleukin-1. It plays a key role in the Toll-like receptor signaling pathway and is involved in innate and adaptive immune responses. In this study, piscine IRAK-4 significantly activated nuclear factor (NF)-κB signaling in grouper spleen cells. Grouper (Epinephelus coioides) IRAK-4 (EcIRAK-4) co-localized with EcMyD88 and did not impair EcMyD88-dependent NF-κB activation. Different doses of EcIRAK-4 caused different degrees of nuclear translocation of the transcription factor NF-κB p65 subunit, and it induced transcription of multiple pro-inflammatory cytokines. Using expression vectors of deletion domains or mutations at important sites of EcIRAK-4, we found that the EcIRAK-4 kinase domain is necessary for its signal transduction function. The conserved amino acid sites performed functions similar to those in mammals, and grouper-specific amino acids such as E339 also played important roles. These findings provide information about the functional characteristics of IRAK-4 in lower vertebrates.