Structural and functional basis of VLDLR usage by Eastern equine encephalitis virus.

The very-low-density lipoprotein receptor (VLDLR) comprises eight LDLR type A (LA) domains and supports entry of distantly related alphaviruses, including Eastern equine encephalitis virus (EEEV) and Semliki Forest virus (SFV). Here, by resolving multiple cryo-electron microscopy structures of EEEV-VLDLR complexes and performing mutagenesis and functional studies, we show that EEEV uses multiple sites (E1/E2 cleft and E2 A domain) to engage more than one LA domain simultaneously. However, no single LA domain is necessary or sufficient to support efficient EEEV infection. Whereas all EEEV strains show conservation of two VLDLR-binding sites, the EEEV PE-6 strain and a few other EEE complex members feature a single amino acid substitution that enables binding of LA domains to an additional site on the E2 B domain. These structural and functional analyses informed the design of a minimal VLDLR decoy receptor that neutralizes EEEV infection and protects mice from lethal challenge.

Vertebrate-class-specific binding modes of the alphavirus receptor MXRA8.

MXRA8 is a receptor for chikungunya (CHIKV) and other arthritogenic alphaviruses with mammalian hosts. However, mammalian MXRA8 does not bind to alphaviruses that infect humans and have avian reservoirs. Here, we show that avian, but not mammalian, MXRA8 can act as a receptor for Sindbis, western equine encephalitis (WEEV), and related alphaviruses with avian reservoirs. Structural analysis of duck MXRA8 complexed with WEEV reveals an inverted binding mode compared with mammalian MXRA8 bound to CHIKV. Whereas both domains of mammalian MXRA8 bind CHIKV E1 and E2, only domain 1 of avian MXRA8 engages WEEV E1, and no appreciable contacts are made with WEEV E2. Using these results, we generated a chimeric avian-mammalian MXRA8 decoy-receptor that neutralizes infection of multiple alphaviruses from distinct antigenic groups in vitro and in vivo. Thus, different alphaviruses can bind MXRA8 encoded by different vertebrate classes with distinct engagement modes, which enables development of broad-spectrum inhibitors.

Structure of Venezuelan equine encephalitis virus in complex with the LDLRAD3 receptor.

LDLRAD3 is a recently defined attachment and entry receptor for Venezuelan equine encephalitis virus (VEEV)1, a New World alphavirus that causes severe neurological disease in humans. Here we present near-atomic-resolution cryo-electron microscopy reconstructions of VEEV virus-like particles alone and in a complex with the ectodomains of LDLRAD3. Domain 1 of LDLRAD3 is a low-density lipoprotein receptor type-A module that binds to VEEV by wedging into a cleft created by two adjacent E2-E1 heterodimers in one trimeric spike, and engages domains A and B of E2 and the fusion loop in E1. Atomic modelling of this interface is supported by mutagenesis and anti-VEEV antibody binding competition assays. Notably, VEEV engages LDLRAD3 in a manner that is similar to the way that arthritogenic alphaviruses bind to the structurally unrelated MXRA8 receptor, but with a much smaller interface. These studies further elucidate the structural basis of alphavirus-receptor interactions, which could inform the development of therapies to mitigate infection and disease against multiple members of this family.

LDLRAD3 is a receptor for Venezuelan equine encephalitis virus.

Venezuelan equine encephalitis virus (VEEV) is a neurotropic alphavirus transmitted by mosquitoes that causes encephalitis and death in humans1. VEEV is a biodefence concern because of its potential for aerosol spread and the current lack of sufficient countermeasures. The host factors that are required for VEEV entry and infection remain poorly characterized. Here, using a genome-wide CRISPR-Cas9-based screen, we identify low-density lipoprotein receptor class A domain-containing 3 (LDLRAD3)-a highly conserved yet poorly characterized member of the scavenger receptor superfamily-as a receptor for VEEV. Gene editing of mouse Ldlrad3 or human LDLRAD3 results in markedly reduced viral infection of neuronal cells, which is restored upon complementation with LDLRAD3. LDLRAD3 binds directly to VEEV particles and enhances virus attachment and internalization into host cells. Genetic studies indicate that domain 1 of LDLRAD3 (LDLRAD3(D1)) is necessary and sufficient to support infection by VEEV, and both anti-LDLRAD3 antibodies and an LDLRAD3(D1)-Fc fusion protein block VEEV infection in cell culture. The pathogenesis of VEEV infection is abrogated in mice with deletions in Ldlrad3, and administration of LDLRAD3(D1)-Fc abolishes disease caused by several subtypes of VEEV, including highly virulent strains. The development of a decoy-receptor fusion protein suggests a strategy for the prevention of severe VEEV infection and associated disease in humans.

Multiple omics analysis reveals the regulation of SIRT5 on mitochondrial function and lipid metabolism during the differentiation of bovine preadipocytes.

Preadipocyte differentiation represents a critical stage in adipogenesis, with mitochondria playing an undeniable pivotal role. Given the intricate interplay between transcription and metabolic signaling during adipogenesis, the regulation of sirtuin 5 (SIRT5) on mitochondrial function and lipid metabolism was revealed via multiple omics analysis. The findings suggest that SIRT5 plays a crucial role in promoting mitochondrial biosynthesis and maintaining mitochondrial function during preadipocyte differentiation. Moreover, SIRT5 modulates the metabolic levels of numerous bioactive substances by extensively regulating genes expression associated with differentiation, energy metabolism, lipid synthesis, and mitochondrial function. Finally, SIRT5 was found to suppress triacylglycerols (TAG) accumulation while enhancing the proportion and diversity of unsaturated fatty acids, and providing conditions for the expansion and stability of membrane structure during mitochondrial biosynthesis through numerous gene regulations. Our findings provide a foundation for the identification of crucial functional genes, signaling pathways, and metabolic substances associated with adipose tissue differentiation and metabolism.

A combined experimental and molecular dynamics simulation study of an intrinsic self-healing polyurethane elastomer based on a dynamic non-covalent mechanism.

An intrinsic self-healing polyurethane (PU) elastomer with excellent self-healing efficiency was prepared. The self-healing properties of this elastomer as well as the temperature dependence of self-healing can be tailored by regulating the molar ratio of hard to soft segments. The self-healing efficiency of 92.5% is the highest when the molar ratio of 4,4-methylenedicyclohexyl diisocyanate (HMDI) to polypropylene carbonate polyol (PPC) is 1.3 and the temperature is 25 °C. In situ temperature swing infrared spectra and low-field nuclear magnetic resonance reveal that the soft segment, PPC, endows PU with a dense dynamic hydrogen bond network, and the dissociation and reconstruction of the hydrogen bond network enable the PU to heal. To date, the exchange of hydrogen bonds has not been observed intuitively through experimental means. Therefore, the number, type, strength, lifetime, and the exchange of hydrogen bonds in the self-healing process at different temperatures were investigated by molecular dynamics (MD) simulation. The simulated results show that the type of hydrogen bond exchange between functional groups will be affected by temperature. The hydrogen bonds between urethane and urea groups play a leading role in the self-healing properties due to the high strength and a large number of hydrogen bonds at both 25 and 50 °C. The stronger strength, longer lifetime, and greater number of effective hydrogen bonds at 25 °C make the self-healing efficiency of PU higher than at 50 °C.

Multiplexing seven miRNA-Based shRNAs to suppress HIV replication.

Multiplexed miRNA-based shRNAs (shRNA-miRs) could have wide potential to simultaneously suppress multiple genes. Here, we describe a simple strategy to express a large number of shRNA-miRs using minimal flanking sequences from multiple endogenous miRNAs. We found that a sequence of 30 nucleotides flanking the miRNA duplex was sufficient for efficient processing of shRNA-miRs. We inserted multiple shRNAs in tandem, each containing minimal flanking sequence from a different miRNA. Deep sequencing of transfected cells showed accurate processing of individual shRNA-miRs and that their expression did not decrease with the distance from the promoter. Moreover, each shRNA was as functionally competent as its singly expressed counterpart. We used this system to express one shRNA-miR targeting CCR5 and six shRNA-miRs targeting the HIV-1 genome. The lentiviral construct was pseudotyped with HIV-1 envelope to allow transduction of both resting and activated primary CD4 T cells. Unlike one shRNA-miR, the seven shRNA-miR transduced T cells nearly abrogated HIV-1 infection in vitro. Additionally, when PBMCs from HIV-1 seropositive individuals were transduced and transplanted into NOD/SCID/IL-2R γc(-/-) mice (Hu-PBL model) efficient suppression of endogenous HIV-1 replication with restoration of CD4 T cell counts was observed. Thus, our multiplexed shRNA appears to provide a promising gene therapeutic approach for HIV-1 infection.

Lower and upper stem-single-stranded RNA junctions together determine the Drosha cleavage site.

Microprocessor [Drosha-DGCR8 (DiGeorge syndrome critical region gene 8) complex] processing of primary microRNA (pri-miRNA) is the critical first step in miRNA biogenesis, but how the Drosha cleavage site is determined has been unclear. Previous models proposed that the Drosha-DGCR8 complex measures either ~22 nt from the upper stem-single-stranded RNA (ssRNA, terminal loop) junction or ~11 nt from the lower stem-ssRNA junction to determine the cleavage site. Here, using miRNA-offset RNAs to determine the Drosha cleavage site, we show that the Microprocessor measures the distances from both the lower and upper stem-ssRNA junctions to determine the cleavage site in human cells, and optimal distances from both structures are critical to the precision of Drosha processing. If the distances are not optimal, Drosha tends to cleave at multiple sites, which can, in turn, generate multiple 5' isomiRs. Thus, our results also reveal a mechanism of 5' isomiR generation.

Prognostic, immunity, stemness, and anticancer drug sensitivity characterization of pyroptosis related genes in non-small cell lung cancer.

BACKGROUND: Pyroptosis plays a pivotal role in the tumor immune microenvironment (TME) dynamics, particularly in non-small cell lung cancer (NSCLC). The aim of our study was to explore its effects on tumor progression, TME patterns, and the efficacy of therapeutic interventions in NSCLC. METHODS: Our investigation encompassed a thorough analysis of pyroptosis-related genes (PRGs), integrating immunohistochemistry (IHC) data, TME characteristics, stemness indices, and anticancer drug sensitivities. We aimed to analyze mRNA expression profiles across various cancers, constructing benchmark datasets to assess the clinical significance of PRGs in NSCLC. This included evaluating their association with clinical responses and efficacy. Notably, both our and HPA IHC data demonstrated significantly elevated GSDMD-N protein levels in lung squamous cell carcinoma (LUSC) tissues. RESULTS: The expression of PRGs differed significantly between tumor and normal tissues across various cancers, as validated by IHC data, and was correlated with prognosis (p < 0.05). Moreover, our investigation revealed significant differences (p < 0.05) in the expression of the PRGs among distinct TME subtypes categorized as C1 (wound healing), C3 (inflammatory), C2 (IFN-gamma dominant), C5 (immunological quiet), C4 (lymphocyte deficient), and C6 (TGF-beta dominant). Additionally, our research on anticancer drug sensitivity uncovered compelling connections between specific anticancer medications and the expression of PRGs, including GSDMD, ELANE, IL18, and CHMP4A (p < 0.05). CONCLUSION: Our study provided valuable insights into the critical role of PRGs in TME modulation, tumor stemness, and anticancer drug sensitivity across diverse cancers. Our findings illuminate the intricate relationship between pyroptosis and the TME, offering new perspectives for enhancing NSCLC treatment and prognosis.

The low-density lipoprotein receptor promotes infection of multiple encephalitic alphaviruses.

Members of the low-density lipoprotein receptor (LDLR) family, including LDLRAD3, VLDLR, and ApoER2, were recently described as entry factors for different alphaviruses. However, based on studies with gene edited cells and knockout mice, blockade or abrogation of these receptors does not fully inhibit alphavirus infection, indicating the existence of additional uncharacterized entry factors. Here, we perform a CRISPR-Cas9 genome-wide loss-of-function screen in mouse neuronal cells with a chimeric alphavirus expressing the Eastern equine encephalitis virus (EEEV) structural proteins and identify LDLR as a candidate receptor. Expression of LDLR on the surface of neuronal or non-neuronal cells facilitates binding and infection of EEEV, Western equine encephalitis virus, and Semliki Forest virus. Domain mapping and binding studies reveal a low-affinity interaction with LA domain 3 (LA3) that can be enhanced by concatenation of LA3 repeats. Soluble decoy proteins with multiple LA3 repeats inhibit EEEV infection in cell culture and in mice. Our results establish LDLR as a low-affinity receptor for multiple alphaviruses and highlight a possible path for developing inhibitors that could mitigate infection and disease.

Structural and functional basis of VLDLR receptor usage by Eastern equine encephalitis virus.

The very low-density lipoprotein receptor (VLDLR) is comprised of eight LDLR type A (LA) domains and supports entry of distantly related Eastern equine encephalitis (EEEV) and Semliki Forest (SFV) alphaviruses. Here, by resolving multiple cryo-electron microscopy structures of EEEV-VLDLR complexes and performing mutagenesis and functional studies, we show that EEEV uses multiple sites (E1/E2 cleft and E2 A domain) to engage different LA domains simultaneously. However, no single LA domain is necessary or sufficient to support efficient EEEV infection, highlighting complexity in domain usage. Whereas all EEEV strains show conservation of two VLDLR binding sites, the EEEV PE-6 strain and other EEE complex members feature a single amino acid substitution that mediates binding of LA domains to an additional site on the E2 B domain. These structural and functional analyses informed the design of a minimal VLDLR decoy receptor that neutralizes EEEV infection and protects mice from lethal challenge.

Structure-function crosstalk in liver cancer research: Protein structuromics.

Liver cancer can be primary (starting in the liver) or secondary (cancer that has spread from elsewhere to the liver, known as liver metastasis). Liver metastasis is more common than primary liver cancer. Despite great advances in molecular biology methods and treatments, liver cancer is still associated with a poor survival rate and a high death rate, and there is no cure. Many questions remain regarding the mechanisms of liver cancer occurrence and development as well as tumor reoccurrence after treatment. In this study, we assessed the protein structural features of 20 oncogenes and 20 anti-oncogenes via protein structure and dynamic analysis methods and 3D structural and systematic analyses of the structure-function relationships of proteins. Our aim was to provide new insights that may inform research on the development and treatment of liver cancer.

The tRNA-GCN2-FBXO22-axis-mediated mTOR ubiquitination senses amino acid insufficiency.

Mammalian target of rapamycin complex 1 (mTORC1) monitors cellular amino acid changes for function, but the molecular mediators of this process remain to be fully defined. Here, we report that depletion of cellular amino acids, either alone or in combination, leads to the ubiquitination of mTOR, which inhibits mTORC1 kinase activity by preventing substrate recruitment. Mechanistically, amino acid depletion causes accumulation of uncharged tRNAs, thereby stimulating GCN2 to phosphorylate FBXO22, which in turn accrues in the cytoplasm and ubiquitinates mTOR at Lys2066 in a K27-linked manner. Accordingly, mutation of mTOR Lys2066 abolished mTOR ubiquitination in response to amino acid depletion, rendering mTOR insensitive to amino acid starvation both in vitro and in vivo. Collectively, these data reveal a novel mechanism of amino acid sensing by mTORC1 via a previously unknown GCN2-FBXO22-mTOR pathway that is uniquely controlled by uncharged tRNAs.

Chinese expert consensus on interventional diagnosis and management of acquired digestive-respiratory tract fistulas (second edition).

Acquired digestive-respiratory tract fistulas occur with abnormal communication between the respiratory tract and digestive tract caused by a variety of benign or malignant diseases, leading to the alimentary canal contents in the respiratory tract. Although various departments have been actively exploring advanced fistula closure techniques, including surgical methods and multimodal therapy, some of which have gotten good clinical effects, there are few large-scale evidence-based medical data to guide clinical diagnosis and treatment. The guidelines update the etiology, classification, pathogenesis, diagnosis, and management of acquired digestive-respiratory tract fistulas. It has been proved that the implantation of the respiratory and digestive stent is the most important and best treatment for acquired digestive-respiratory tract fistulas. The guidelines conduct an in-depth review of the current evidence and introduce in detail the selection of stents, implantation methods, postoperative management and efficacy evaluation.

Furin extracellularly cleaves secreted PTENα/ß to generate C-terminal fragment with a tumor-suppressive role.

PTENα and PTENß (PTENα/ß), two long translational variants of phosphatase and tensin homolog on chromosome 10 (PTEN), exert distinct roles from canonical PTEN, including promoting carcinogenesis and accelerating immune-resistant cancer progression. However, their roles in carcinogenesis remain greatly unknown. Herein, we report that, after secreting into the extracellular space, PTENα/ß proteins are efficiently cleaved into a short N-terminal and a long C-terminal fragment by the proprotein convertase Furin at a polyarginine stretch in their N-terminal extensions. Although secreted PTENα/ß and their cleaved fragment cannot enter cells, treatment of the purified C-terminal fragment but not cleavage-resistant mutants of PTENα exerts a tumor-suppressive role in vivo. As a result, overexpression of cleavage-resistant PTENα mutants manifest a tumor-promoting role more profound than that of wild-type PTENα. In line with these, the C-terminal fragment is significantly downregulated in liver cancer tissues compared to paired normal tissues, which is consistent with the downregulated expression of Furin. Collectively, we show that extracellular PTENα/ß present opposite effects on carcinogenesis from intracellular PTENα/ß, and propose that the tumor-suppressive C-terminal fragment of PTENα/ß might be used as exogenous agent to treat cancer.

Effects of dietary ß-glucan, mannan oligosaccharide and their combinations on growth performance, immunity and resistance against Vibrio splendidus of sea cucumber, Apostichopus japonicus.

A 4-week feeding trial was conducted to investigate the effects of dietary ß-glucan, mannan oligosaccharide (MOS) and their combinations on growth performance, immunity and disease resistance of sea cucumber Apostichopus japonicus. Sea cucumbers (1215 individuals with initial weight of 3.8 ± 0.2 g) were fed nine practical diets according to a 3 × 3 factorial design: the basal diet as the control supplemented with three levels of ß-glucan (0, 0.075, 0.15% w/w), crossed with 0, 0.1% (w/w) or 0.2% (w/w) MOS. Immune indices including total coelomocytes count (TCC), phagocytosis, superoxide anion production, superoxide dismutase (SOD) activity and total nitric oxide synthase activity (T-NOS) were measured at days 7, 11, 15, 18, 22, 25 and 29. At the end of the feeding trial, all the sea cucumbers left were weighted to monitor growth, and then were challenged by Vibrio splendidus. The results showed that dietary ß-glucan, MOS and their combinations significantly increased TCC, phagocytosis, superoxide anion production and SOD activity of sea cucumbers (P < 0.05). Only 0.15% ß-glucan and the combinations of ß-glucan and MOS significantly increased the T-NOS activity (P < 0.05). A synergistic effect was found between dietary ß-glucan and MOS. Moreover, combinations of ß-glucan and MOS prolonged the high levels of immune indices compared with ß-glucan or MOS supplementation alone. Except the 0.15% ß-glucan group, all the other treatments showed significantly lower cumulative mortality compared with control (P < 0.05). Furthermore, combination of 0.15% ß-glucan and 0.1% MOS had the best effects on enhancing disease resistance of sea cucumber. All treatments showed significantly higher specific growth rate (SGR) compared with control (P < 0.05), and the combination of 0.15% ß-glucan and 0.1% MOS was significantly higher than other treatments (P < 0.05). In conclusion, our results confirm the potential of ß-glucan and MOS as dietary immunostimulants and the synergistic effects of ß-glucan and MOS on A. japonicus.

Prognostic factors and survival outcome of primary pulmonary acinar cell carcinoma.

PURPOSE: The objective of our study was to investigate the epidemiologic characteristics and prognostic factors in patients with pulmonary acinar cell carcinoma (PACC). METHODS: PACC patients diagnosed between 1975 and 2016 were identified from the Surveillance, Epidemiology, and End Results (SEER) database. The trend in PACC incidence was assessed using joinpoint regression software. Overall survival (OS) and disease-specific survival (DSS) were evaluated using the Kaplan-Meier method and log-rank test. Univariate and multivariate Cox regression analysis was performed to identify the independent prognostic factors for OS and DSS. Nomograms to predict survival possibilities were constructed based on the identified independent prognostic factors. RESULTS: A total of 2918 patients were identified with PACC. The mean age was 65.2 ± 8.95 years with a female to male of 1.6:1. The incidence of PACC steadily increased by an annual percentage change (APC) of 3.2% (95% CI 2.1-4.4, p < 0.05). Multivariate Cox regression analysis revealed that age, gender, race, stage, grade, tumor size, number of positive lymph nodes, surgery, and chemotherapy were independent prognostic factors for survival. Nomograms specifically for PACC were constructed to predict 1- and 5-year OS and DSS possibility, respectively. The concordance index (C-index) and calibration plots showed the established nomograms had robust and accurate performance. CONCLUSION: PACC was rare but the incidence has been steadily increasing over the past four decades. Survival has improved in recent years. Surgery or chemotherapy could provide better OS and DSS. The established nomograms specifically for PACC were robust and accurate in predicting 1- and 5-year OS and DSS.

Intercellular Mitochondria Transfer to Macrophages Regulates White Adipose Tissue Homeostasis and Is Impaired in Obesity.

Recent studies suggest that mitochondria can be transferred between cells to support the survival of metabolically compromised cells. However, whether intercellular mitochondria transfer occurs in white adipose tissue (WAT) or regulates metabolic homeostasis in vivo remains unknown. We found that macrophages acquire mitochondria from neighboring adipocytes in vivo and that this process defines a transcriptionally distinct macrophage subpopulation. A genome-wide CRISPR-Cas9 knockout screen revealed that mitochondria uptake depends on heparan sulfates (HS). High-fat diet (HFD)-induced obese mice exhibit lower HS levels on WAT macrophages and decreased intercellular mitochondria transfer from adipocytes to macrophages. Deletion of the HS biosynthetic gene Ext1 in myeloid cells decreases mitochondria uptake by WAT macrophages, increases WAT mass, lowers energy expenditure, and exacerbates HFD-induced obesity in vivo. Collectively, this study suggests that adipocytes and macrophages employ intercellular mitochondria transfer as a mechanism of immunometabolic crosstalk that regulates metabolic homeostasis and is impaired in obesity.

Interaction of dietary Bacillus subtilis and fructooligosaccharide on the growth performance, non-specific immunity of sea cucumber, Apostichopus japonicus.

A feeding experiment was conducted to investigate the interaction of probiotic Bacillus subtilis and prebiotic fructooligosaccharide (FOS) on the growth performance, immunity, intestinal microflora and disease resistance of sea cucumber (Apostichopus japonicus). Five hundred and forty individuals (initial body weight: 5.06 +/- 0.10 g, mean +/- S.E) were fed nine practical diets according to a 3 x 3 factorial design: the basal diet as the control diet supplemented with three levels of B. subtilis (0, 1.82 x 10(7) or 4.95 x 10(7) CFU g(-1) diet), crossed with 0, 0.25% or 0.50% FOS. After 8 weeks, three sea cucumbers per tank were sampled for bacterial quantification and immunity determination. Then all the sea cucumbers left were challenged by Vibrio splendidus. The results showed that dietary B. subtilis significantly increased the specific growth rate (SGR), total coelomocytes counts (TCC), phagocytosis of sea cucumbers, the counts of total viable bacteria and disease resistance to V. splendidus (P < 0.05), whereas the counts of Vibrio decreased. However, dietary B. subtilis had no significant effect on phenoloxidase (PO) activity in coelomocyte lysate supernatant (CLS) (P > 0.05). The SGR, PO activity, total viable bacterial counts (TBC) and Vibrio counts (VBC) were significantly affected by dietary FOS. In the group with 0.50% FOS, TCC, phagocytosis and PO activity significantly increased compared to the group fed without FOS in diet (P < 0.05). In the groups with 1.82 x 10(7) CFU B. subtilis/g diet, FOS supplementation remarkably decreased VBC. And higher level of FOS (0.50%) resulted in significantly higher TCC and PO activity compared with 0.25% FOS (P < 0.05). Moreover, the animals fed with diets supplemented with 0.25% and 0.50% FOS at each B. subtilis level had notably lower cumulative mortality after 14 days following V. splendidus exposure (P < 0.05). Under the experimental conditions, dietary B. subtilis and FOS had a synergistic effect on enhancing immunity and disease resistance of sea cucumber (P < 0.05).

Molecular cloning, characterization and mRNA expression of selenium-binding protein in abalone (Haliotis discus hannai Ino): Response to dietary selenium, iron and zinc.

Selenium-binding protein (SEBP) is believed to play crucial role in controlling the oxidation/reduction in the physiological processes. In this study, the cDNA of selenium-binding protein from abalone Haliotis discus hannai Ino (HdhSEBP) was cloned by homology cloning and rapid amplification of cDNA ends (RACE) technique. The full length of HdhSEBP cDNA was 2071 bp, consisting of a 5' untranslated region (UTR) of 55 bp, a 3' UTR of 522 bp, and an open reading frame (ORF) of 1494 bp. The deduced protein has 497 amino acid residues with a calculated molecular mass of 55.6 kDa and a predicted isoelectric point of 5.47. BLAST analysis reveals that HdhSEBP shares high identities with other known SEBPs from mammal, bird, fish and mollusk, etc. The mRNA expression patterns of HdhSEBP in hepatopancreas and haemocytes were measured by real-time PCR in abalone fed with nine different diets containing graded levels of selenium (0, 1 and 50 mg kg(-1)), iron (0, 65 and 1300 mg kg(-1)) and zinc (0, 35 and 700 mg kg(-1)) for 20 weeks, respectively. The results showed that the expression of the HdhSEBP mRNA increased and reached the maximum at optimal dietary selenium (1 mg kg(-1)), iron (65 mg kg(-1)) and zinc (35 mg kg(-1)), respectively. Deficient or excessive level of dietary selenium, iron or zinc, respectively, leaded to significant depression of HdhSEBP mRNA. It is concluded that the expression levels of HdhSEBP are affected by dietary selenium, iron or zinc.