Copolymerization Involving Sulfur-Containing Monomers.

Incorporating sulfur (S) atoms into polymer main chains endows these materials with many attractive features, including a high refractive index, mechanical properties, electrochemical properties, and adhesive ability to heavy metal ions. The copolymerization involving S-containing monomers constitutes a facile method for effectively constructing S-containing polymers with diverse structures, readily tunable sequences, and topological structures. In this review, we describe the recent advances in the synthesis of S-containing polymers via copolymerization or multicomponent polymerization techniques concerning a variety of S-containing monomers, such as dithiols, carbon disulfide, carbonyl sulfide, cyclic thioanhydrides, episulfides and elemental sulfur (S8). Particularly, significant focus is paid to precise control of the main-chain sequence, stereochemistry, and topological structure for achieving high-value applications.

IFNh and IRF9 influence the transcription of MHCII mediated by IFNγ to maintain immune balance in sea perch lateolabrax japonicus.

The major histocompatibility complex class II (MHCII) molecules are crucial elements of the adaptive immune system, essential for orchestrating immune responses against foreign pathogens. However, excessive expression of MHCII can disrupt normal physiological functions. Therefore, the host employs various mechanisms to regulate MHCII expression and maintain immune homeostasis. Despite this importance, limited studies have explored the negative regulation of MHCII transcription in bony fish. In this study, we found that interferon h (IFNh), a subtype of type I IFN in sea perch Lateolabrax japonicus, could inhibit the activation of IFNγ induced-MHCII expression by modulating the transcription of the class II major histocompatibility complex transactivator (CIITA). Transcriptome analysis revealed 57 up-regulated and 69 down-regulated genes in cells treated with both IFNγ and IFNh compared to those treated with IFNγ alone. To maintain cellular homeostasis, interferon regulatory factor 9 (IRF9) was up-regulated following IFNγ stimulation, thereby preventing MHCII overexpression. Mechanistically, IRF9 bound to the CIITA promoter and suppressed its expression activated by IRF1. Furthermore, IRF9 inhibited the promoter activity of both MHCII-α and MHCII-ß induced by CIITA. Our findings highlight the roles of IFNh and IRF9 as suppressors regulating MHCII expression at different hierarchical levels. This study provides insights into the intricate regulation of antigen presentation and the foundation for further exploration of the interaction mechanisms between aquatic virus and fish.

Protective efficacy and immune responses of largemouth bass (Micropterus salmoides) immunized with an inactivated vaccine against the viral hemorrhagic septicemia virus genotype IVa.

Viral hemorrhagic septicemia virus (VHSV) poses a significant threat to the aquaculture industry, prompting the need for effective preventive measures. Here, we developed an inactivated VHSV and revealed the molecular mechanisms underlying the host's protective response against VHSV. The vaccine was created by treating VHSV with 0.05 % formalin at 16 °C for 48 h, which was determined to be the most effective inactivation method. Compared with nonvaccinated fish, vaccinated fish exhibited a remarkable increase in survival rate (99 %) and elevated levels of serum neutralizing antibodies, indicating strong immunization. To investigate the gene changes induced by vaccination, RNA sequencing was performed on spleen samples from control and vaccinated fish 14 days after vaccination. The analysis revealed 893 differentially expressed genes (DEGs), with notable up-regulation of immune-related genes such as annexin A1a, coxsackievirus and adenovirus receptor homolog, V-set domain-containing T-cell activation inhibitor 1-like, and heat shock protein 90 alpha class A member 1 tandem duplicate 2, indicating a vigorous innate immune response. Furthermore, KEGG enrichment analysis highlighted significant enrichment of DEGs in processes related to antigen processing and presentation, necroptosis, and viral carcinogenesis. GO enrichment analysis further revealed enrichment of DEGs related to the regulation of type I interferon (IFN) production, type I IFN production, and negative regulation of viral processes. Moreover, protein-protein interaction network analysis identified central hub genes, including IRF3 and HSP90AA1.2, suggesting their crucial roles in coordinating the immune response elicited by the vaccine. These findings not only confirm the effectiveness of our vaccine formulation but also offer valuable insights into the underlying immunological mechanisms, which can be valuable for future vaccine development and disease management in the aquaculture industry.

Iron-catalyzed selective construction of indole derivatives via oxidative C(sp3)-H functionalization of indolin-2-ones.

Considering the importance of developing powerful catalysts and the pharmacophore characteristics of indole derivatives, we describe a switchable approach for the iron-catalyzed oxidative C(sp3)-H functionalization of indolin-2-ones. Selective transformations displayed excellent activity and chemoselectivity using FeCl2 as the catalyst, air as the oxidant, and alcohol as the solvent. By manipulating the reaction conditions, particularly the choice of solvent, catalyst loading, and reaction sequence, a series of valuable indole derivatives, including isatins and symmetrical and nonsymmetrical isoindigos, were selectively synthesized in good to excellent yields. Furthermore, the gram-scale synthesis of compounds with biological anticancer activity under simple conditions highlights their great potential in practical applications.

N Protein of Viral Hemorrhagic Septicemia Virus Suppresses STAT1-Mediated MHC Class II Transcription to Impair Antigen Presentation in Sea Perch, Lateolabrax japonicus.

Upon virus invasion of the host, APCs process Ags to short peptides for presentation by MHC class II (MHC-II). The recognition of virus-derived peptides in the context of MHC-II by CD4+ T cells initiates the adaptive immune response for virus clearance. As a survival instinct, viruses have evolved mechanisms to evade Ag processing and presentation. In this study, we discovered that IFN-γ induced endogenous MHC-II expression by a sea perch brain cell line through the STAT1/IFN regulatory factor 1 (IRF1)/CIITA signaling pathway. Furthermore, viral hemorrhagic septicemia virus infection significantly inhibited the IFN-γ-induced expression of IRF1, CIITA, MHC-II-α, and MHC-II-ß genes. By contrast, although STAT1 transcript was upregulated, paradoxically, the STAT1 protein level was attenuated. Moreover, overexpression analysis revealed that viral hemorrhagic septicemia virus N protein blocked the IFN-γ-induced expression of IRF1, CIITA, MHC-II-α, and MHC-II-ß genes, but not the STAT1 gene. We also found out that N protein interacted with STAT1 and enhanced the overall ubiquitination level of proteins, including STAT1 in Lateolabrax japonicus brain cells. Enhanced ubiquitination of STAT1 through K48-linked ubiquitination led to its degradation through the ubiquitin-proteasome pathway, thereby inhibiting the biological function of STAT1. Our study suggests that aquatic viruses target Ag presentation in lower vertebrates for immune evasion as do mammalian viruses.

The Capsid Protein of Nervous Necrosis Virus Antagonizes Host Type I IFN Production by a Dual Strategy to Negatively Regulate Retinoic Acid-Inducible Gene-I-like Receptor Pathways.

Nervous necrosis virus (NNV), a highly pathogenic RNA virus, is a major pathogen in the global aquaculture industry. To efficiently infect fish, NNV must evade or subvert the host IFN for their replication; however, the precise mechanisms remain to be elucidated. In this study, we reported that capsid protein (CP) of red-spotted grouper NNV (RGNNV) suppressed the IFN antiviral response to promote RGNNV replication in Lateolabrax japonicus brain cells, which depended on the ARM, S, and P domains of CP. CP showed an indirect or direct association with the key components of retinoic acid-inducible gene-I-like receptors signaling, L. japonicus TNFR-associated factor 3 (LjTRAF3) and IFN regulatory factor (LjIRF3), respectively, and degraded LjTRAF3 and LjIRF3 through the ubiquitin-proteasome pathway in HEK293T cells. Furthermore, we found that CP potentiated LjTRAF3 K48 ubiquitination degradation in a L. japonicus ring finger protein 114-dependent manner. LjIRF3 interacted with CP through the S domain of CP and the transcriptional activation domain or regulatory domain of LjIRF3. CP promoted LjIRF3 K48 ubiquitination degradation, leading to the reduced phosphorylation level and nuclear translocation of LjIRF3. Taken together, we demonstrated that CP inhibited type I IFN response by a dual strategy to potentiate the ubiquitination degradation of LjTRAF3 and LjIRF3. This study reveals a novel mechanism of RGNNV evading host immune response via its CP protein that will provide insights into the complex pathogenesis of NNV.

Innovative Approach to Chiral Polyurethanes: Asymmetric Copolymerization with Isocyanates.

The introduction of nitrogen-containing functional groups to chiral polymer backbones enables the tailoring of physical properties and offers opportunities for further post-polymerization modification. However, the substrate scope of such polymers is extremely limited because monomers having nitrogen-containing groups can change coordination state with respect to the metal centers, thus decreasing the activity and enantioselectivity and even poisoning the catalyst completely. In this paper, we report our attempts to carry out the asymmetric copolymerization of meso-epoxide with highly reactive isocyanates. In particular, we found that biphenol-linked bimetallic Co(III) complexes with multiple chiral centers are very efficient in catalyzing this asymmetric copolymerization reaction, affording optically active polyurethanes with a completely alternating nature and a high enantioselectivity of up to 94 % ee. Crucially, we identified that the steric hindrance at the phenolate ortho position of the ligand strongly influences the catalytic activity and product enantioselectivity. In addition, density functional theory calculations revealed that the highly sterically bulky substituents change the mechanism from bimetallic to monometallic, and result in the unexpected inversion of the chiral induction direction. Moreover, the high stereoregularity of the produced polyurethanes enhances their thermal stability, and they can be selectively decomposed into oxazolidinones. This study offers a versatile methodology for the synthesis of chiral polymers containing nitrogen functionalities.

A Powerful Strategy for Synthesizing Block Copolymers via Bimetallic Synergistic Catalysis.

Block copolymers, comprising polyether and polyolefin segments, are an important and promising category of functional materials. However, the lack of efficient strategies for the construction of polyether-b-polyolefin block copolymers have hindered the development of these materials. Herein, we propose a simple and efficient method to obtain various block copolymers through the copolymerization of epoxides and acrylates via bimetallic synergistic catalysis. The copolymerization of epoxides and acrylates proceeds in a sequence-controlled manner, where the epoxides-involved homo- or copolymerization occurs first, followed by the homopolymerization of acrylates initiated by the alkoxide species from the propagating polymer chain, thus yielding copolymers with a block structure. Notably, the high monomer compatibility of this powerful strategy provides a platform for synthesizing various polyacrylate-based block copolymers comprising polyether, polycarbonate, polythiocarbonate, polyester, and polyurethane segments, respectively.

Emerging Trends in Closed-Loop Recycling Polymers: Monomer Design and Catalytic Bulk Depolymerization.

Plastics are indispensable materials in modern society; however, their extensive use has contributed to the depletion of finite natural resources and caused severe environmental issues. One end-of-use solution for plastics involves the chemical recycling of polymers back to monomers for repolymerization to virgin polymers without changing the material properties, allowing the establishment of a circular material economy. This concept focuses on the critical advantages of chemically recyclable polymers in terms of monomer design, material properties, and the feasibility of bulk depolymerization. The recyclability via bulk thermolysis of various polyesters, CO2 -based polycarbonates, and polyacetals produced via ring-opening polymerization is highlighted through discussions regarding rational monomer design and efficient catalyst development. An outlook and perspective are provided to delineate the future challenges in the rational design of monomer and polymer structures that deliver the desired materials performance while being suitable for bulk thermolysis with high (de)polymerization activity and selectivity.

Eletrocarboxylation Reactions Using CO2 Both as Promoter and Carboxylative Reagent.

Electrocarboxylation reaction, which employs organic electrosynthesis to achieve the utilization of CO2 as a carboxylative reagent, provides a powerful and efficient tool for the preparation of organic carboxylic acid. In some electrocarboxylation reactions, CO2 also acts as a promoter to facilitate the desired reaction. This concept mainly highlights recent CO2 -promoted electrocarboxylation reactions via CO2 ⋅- intermediate or transiently protective carboxylation of active intermediate with CO2 .

Electroreductive Ring-Opening Carboxylation of Cycloketone Oxime Esters with Carbon Dioxide.

Electroreductive ring-opening carboxylation of cycloketone oxime esters with atmospheric carbon dioxide is reported. This reaction proceeded under simple constant current conditions in an undivided cell using glassy carbon as the cathode and magnesium as the sacrificial anode, providing substituted γ- and δ-cyanocarboxylic acids in moderate to good yields. Electrochemically generated cyanoalkyl radicals and cyanoalkyl anion are proposed as the key intermediates.

Molecular characterization, transcriptional regulation of sea perch Moloney leukemia virus 10 and its antiviral function against VHSV.

Moloney leukemia virus 10 (MOV10) is a conserved RNA helicase and has multiple biological functions in mammals, but its role remains poorly understood in bony fish. Here, we cloned a MOV10 homolog from sea perch (Lateolabrax japonicus), which contained 23 exons and 22 introns, with an open reading frame of 3000 bp encoding 1000 amino acids. Tissue distribution analysis showed that MOV10 was high expressed in blood of sea perch. Promoter analysis revealed several putative multiple transcription factors binding sites, including upstream transcription factor 1, GATA-box, transcription initiation factor IIB, activator protein 1 and two interferon (IFN) stimulated response elements. Further analysis found that IFNc, IFNh, and IFNγ could not only activate IFN regulatory factor (IRF) 1 expression which in turn led to the induction of MOV10, but also prompted the expression of IRF10 to hinder excessive MOV10 expression. Moreover, IRF2 also suppressed MOV10 expression that was initiated by IRF1. Viral hemorrhagic septicemia virus (VHSV) infection upregulated MOV10 expression in vivo and in vitro, which in turn, enhanced IFNh expression and exhibited strong antiviral activity against VHSV proliferation. This study provides a basis to investigate the immune escape of VHSV by affecting the biological function of transcription factors in the signaling pathways associated with antiviral molecules.

Favorable Propylene-Incorporated Terpolymerization of Ethylene with CO Mediated by Cationic [P,O]-Pd and Ni Complexes.

Commercial polyketone materials are generally produced by palladium-catalyzed terpolymerization of ethylene and α-olefin with carbon monoxide (CO), and rare examples were reported regarding the incorporation of propylene into an ethylene/CO copolymer chain using a cost-effective nickel catalyst. In this study, we have developed a series of [P,O]-type cationic Pd and Ni complexes supported by a diphosphazane monoxide (PNPO) platform, and the electronic and steric effect on phosphine, amine, and phosphine oxide moieties is systematically investigated for terpolymerization in terms of activity, propylene/CO (C3) incorporation, and molecular weight control. It is observed that the melting temperature (Tm) is proportional to the number of C3 incorporations present in the polymer chain, and the incorporated propylene does not affect the degradation temperature substantially, thus broadening the processing temperature window of the resultant polyketones. Notably, in comparison with dppp-type catalysts, PNPO catalysts exhibited a higher preference for propylene consumption, which is of great importance for making more efficient use of α-olefin resources.

E3 Ubiquitin Ligase RNF114 Inhibits Innate Immune Response to Red-Spotted Grouper Nervous Necrosis Virus Infection in Sea Perch by Targeting MAVS and TRAF3 to Mediate Their Degradation.

RIG-I-like receptor (RLR)-mediated antiviral signaling is critical to trigger the immune response to virus infection; however, the antiviral responses are also tightly regulated to avoid uncontrolled production of type I IFN by various mechanisms, including ubiquitination. In this study, an E3 ubiquitin ligase ring finger protein 114 (RNF114) from sea perch (Lateolabrax japonicus) (LjRNF114) was identified as a suppressor of RLR signaling pathways during red-spotted grouper nervous necrosis virus (RGNNV) infection. RGNNV infection promoted the expression of LjRNF114. Overexpression of LjRNF114 enhanced RGNNV replication, whereas knockdown of LjRNF114 led to opposite effects. Type I IFN production induced by RGNNV was suppressed by LjRNF114, which is dependent on its ubiquitin ligase activity. Moreover, LjRNF114 inhibited IFN promoter activation induced by key signaling molecules in RLR signaling pathways. We observed the interactions between LjRNF114 and both sea perch mitochondrial antiviral signaling protein (MAVS) and TNFR-associated factor 3 (TRAF3). Domain mapping experiments indicated that the RING and ubiquitin interacting motif domains of LjRNF114 were required for its interaction with TRAF3 and MAVS. We found that LjRNF114 targeted MAVS and TRAF3 for K27- and K48-linked ubiquitination and degradation, resulting in the inhibition of IFN production. Taken together, our study reveals, to our knowledge, a novel mechanism that LjRNF114 targets and promotes K27- and K48-linked ubiquitination of MAVS and TRAF3 to negatively regulate the RLR signaling pathways, promoting viral infection.

Preparation of Poly(ß-malic acid) via Direct Carbonylative Polymerization of Benzyl Glycidate.

Poly(malic acid) (PMLA) is a water-soluble, biodegradable, biocompatible, and nontoxic polyester in the poly(hydroxyalkanoate) (PHA) family. it features various applications in pharmaceutical field. Herein, NaCo(CO)4 and pyridine derivatives are employed for direct carbonylative polymerization of benzyl glycidate (BG) for poly(ß-malic acid) production. Further investigation on reaction mechanism reveals that this polymerization undergoes a direct chain growth, rather than a sequential process involving ß-lactone intermediate. The low cost and facile preparation of epoxide substrate render this methodology extremely appealing that avoids the rather tedious procedures for ß-malolactonate synthesis required toward ring opening polymerization. This study also represents an alternative strategy over traditional methods for poly(ß-malic acid) production using step growth polycondensation of malic acid.

The association of SOD and HsCRP with the efficacy of sulforaphane in schizophrenia patients with residual negative symptoms.

OBJECTIVES: Emerging evidence indicates a connection between oxidative stress, immune-inflammatory processes, and the negative symptoms of schizophrenia. In addition to possessing potent antioxidant and anti-inflammatory properties, sulforaphane (SFN) has shown promise in enhancing cognitive function among individuals with schizophrenia. This study aims to investigate the efficacy of combined treatment with SFN in patients with schizophrenia who experience negative symptoms and its effect on the levels of superoxide dismutase (SOD) and the inflammatory marker, high-sensitivity C-reactive protein (HsCRP). DESIGN: Forty-five patients with schizophrenia were recruited, who mainly experienced negative symptoms during a stable period. In addition to the original treatments, the patients received SFN tablets at a daily dose of 90 mg for 24 weeks. At baseline, 12 weeks, and 24 weeks, the participants were interviewed and evaluated. The reduction rate of the Positive and Negative Syndrome Scale (PANSS) was used to assess each participant. The side effects scale of Treatment Emergent Symptom Scale (TESS) was applied to assess the adverse reactions. Additionally, the levels of the SOD, HsCRP, and other indicators were examined. RESULTS: The study findings revealed a significant decrease in PANSS negative subscale scores (P < 0.001). Furthermore, there was a significant increase in SOD activity and HsCRP levels (P < 0.001 and P < 0.05). Notably, the group of participants who exhibited a reduction in PANSS negative subscale scores demonstrated a significant improvement in HsCRP levels (P < 0.05). CONCLUSIONS: Our study suggests that SFN may potentially serve as a safe adjunctive intervention to improve the negative symptoms of schizophrenia. The potential mechanism by which SFN improves negative symptoms in schizophrenia patients may involve its anti-inflammatory properties, specifically its ability to reduce HsCRP levels. Trial registration ClinicalTrial.gov (ID: NCT03451734).

Enantioselective terpolymerization of racemic and meso-epoxides with anhydrides for preparation of chiral polyesters.

The preparation of stereochemistry- and sequence-defined polymers, in which different monomer units are arranged in an ordered fashion just like biopolymers, is of great interest and has been a long-standing goal for chemists due to the expectation of unique macroscopic properties. Here, we describe the enantioselective terpolymerization of racemic terminal epoxides, meso-epoxides, and anhydrides mediated by the privileged chiral dinuclear Al(III) catalyst system, to afford optically active polyester terpolymers with either gradient or random distribution as determined by the epoxides employed during their preparation. The enantioselective terpolymerization of racemic tert-butyl glycidyl ether (rac-TBGE) and cyclopentene oxide with phthalic anhydride (PA) or naphthyl anhydride (NA) gives novel gradient polyesters, in which the crystallization behavior varies continuously along the main chain, due to the decrement of one ester component and the increment of the other occurring sequentially from one chain end to the other. In contrast, the enantioselective terpolymerization of rac-TBGE and meso-epoxide (cyclohexene oxide, 3,4-epoxytetrahydrofuran, or 1,4-dihydronaphthalene oxide) with an anhydride (PA or NA) provided chiral statistical terpolyesters with the random distribution of two kinds of ester units, resulting in a material possessing a mixed glass transition temperature. The present study therefore provides a convenient route to chiral polyesters bearing a range of physical and degradability properties.

Azopolyesters with Intrinsic Crystallinity and Photoswitchable Reversible Solid-to-Liquid Transitions.

Herein, we introduce a variety of azopolyesters (azobenzene-based polyesters) with remarkable intrinsic crystallinity and photoinduced reversible solid-to-liquid transition abilities from copolymerization of azobenzene-based epoxides with cyclic anhydrides. The length of the soft alkyl side-chain inlaid with azobenzenes and stereoregularity of main-chain of azopolymers have tremendous effects on crystallization properties of the resulting polyesters with melting temperature (Tm ) in the range of 51-251 °C. Moreover, some of azopolyesters possess excellently photoinduced reversible solid-to-liquid transition performance thanks to trans-cis photoisomerization of azobenzenes. Trans-azopolyesters are yellow solids with Tm s or glass transition temperatures (Tg s) above room temperature, whereas cis-polymers are red liquids with Tg s below -20 °C. These azopolyesters could be applied as novel light-switchable adhesives for quartz/quartz, wood/wood and quartz/wood adhesion, with the strength in the range of 0.73-0.89 MPa for trans-polymers. Conversely, the adhesion strength of liquefied cis-azopolyesters generated from the irradiation of trans-polymers by UV light was about 0.1 MPa, which shows light enable to control the adhesion process with high spatiotemporal resolution.

Sequence Control in Asymmetric Terpolymerizations of meso-Epoxides, CO2 , and Phthalic Anhydride: Unprecedented Statistical Ester-Carbonate Distributions.

The statistical terpolymerization of epoxides, CO2 and cyclic anhydrides remains challenging, mainly because epoxide/CO2 and epoxide/anhydride copolymerizations typically proceed at considerably different rates. Herein, we report the syntheses of novel chiral terpolymers with unprecedented statistical distributions of carbonate and ester units (up to 50 % junction units) via the one-pot reaction of cyclohexene oxide, phthalic anhydride, and CO2 under mild conditions using enantiopure bimetallic aluminum-complex-based catalyst systems. Notably, all resulting terpolymers exhibited excellent enantioselectivities (≥96 % ee) that were independent of the carbonate-ester distribution. The statistical compositions of the carbonate and ester units in the resulting terpolymers were determined via 1 H and 13 C NMR spectroscopies. Furthermore, thermal properties were tuned by altering the ester content of the chiral terpolymer without influencing the enantioselective ring-opening step involving the meso-epoxide. This asymmetric terpolymerization methodology is also compatible with a variety of meso-epoxides to afford the corresponding terpolymers with 17 %-25 % junction units and excellent enantioselectivities (94 %-99 % ee). The present study is expected to provide new guidelines for preparing a broad range of biodegradable polymers with excellent enantioselectivities and adjustable properties.

Marine medaka heat shock protein 90ab1 is a receptor for red-spotted grouper nervous necrosis virus and promotes virus internalization through clathrin-mediated endocytosis.

Nervous necrosis virus (NNV) can infect many species of fish and causes serious acute or persistent infection. However, its pathogenic mechanism is still far from clear. Specific cellular surface receptors are crucial determinants of the species tropism of a virus and its pathogenesis. Here, the heat shock protein 90ab1 of marine model fish species marine medaka (MmHSP90ab1) was identified as a novel receptor of red-spotted grouper NNV (RGNNV). MmHSP90ab1 interacted directly with RGNNV capsid protein (CP). Specifically, MmHSP90ab1 bound to the linker region (LR) of CP through its NM domain. Inhibition of MmHSP90ab1 by HSP90-specific inhibitors or MmHSP90ab1 siRNA caused significant inhibition of viral binding and entry, whereas its overexpression led to the opposite effect. The binding of RGNNV to cultured marine medaka hMMES1 cells was inhibited by blocking cell surface-localized MmHSP90ab1 with anti-HSP90ß antibodies or pretreating virus with recombinant MmHSP90ab1 or MmHSP90ab1-NM protein, indicating MmHSP90ab1 was an attachment receptor for RGNNV. Furthermore, we found that MmHSP90ab1 formed a complex with CP and marine medaka heat shock cognate 70, a known NNV receptor. Exogenous expression of MmHSP90ab1 independently facilitated the internalization of RGNNV into RGNNV impenetrable cells (HEK293T), which was blocked by chlorpromazine, an inhibitor of clathrin-dependent endocytosis. Further study revealed that MmHSP90ab1 interacted with the marine medaka clathrin heavy chain. Collectively, these data suggest that MmHSP90ab1 is a functional part of the RGNNV receptor complex and involved in the internalization of RGNNV via the clathrin endocytosis pathway.