Search PubMed⌕ Search

Biomedical subjects

Kai Yang

Publications and source records attributed to Kai Yang.

At least 19 recordsLinked to original sources

Zhiling Jiangya decoction treats hypertension in rats: An integrative study of network pharmacology, immune infiltration, molecular simulation, and 16S rDNA sequencing.

OBJECTIVE: This study integrated network pharmacology, immune infiltration analysis, molecular docking, molecular dynamics simulation, ADMET prediction, 16S rDNA sequencing, and rat experiments to elucidate the potential mechanisms underlying the antihypertensive effects of Zhiling Jiangya Decoction (ZLJYD). METHODS: Active compounds and their potential targets were screened from the PubChem, TCMSP, NovoPro, and SwissTargetPrediction databases. Hypertension-related targets were retrieved from the OMIM and GeneCards databases, and overlapping targets were identified. The STRING database and Cytoscape 3.10.1 software were used to construct a protein-protein interaction network and a herb-component-target-disease network. Gene Ontology functional enrichment analysis and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis were performed to identify the key biological processes and signaling pathways involved. Using the CIBERSORT algorithm combined with correlation analysis, we investigated the association between key targets and immune cell infiltration. Molecular docking, molecular dynamics simulations, and ADMET predictions were performed to assess the binding stability and pharmacokinetic properties of the main compounds with their corresponding targets. Finally, the antihypertensive efficacy of ZLJYD was validated using a spontaneously hypertensive rat model, and alterations in gut microbiota were analyzed using 16S rDNA sequencing. RESULTS: A total of 123 active compounds and 267 hypertension-related targets of ZLJYD were identified. Enrichment analysis revealed that these targets were primarily associated with the PI3K-Akt signaling pathway and lipid and atherosclerosis pathways. Immune infiltration analysis suggested that the therapeutic effects of ZLJYD may involve the regulation of follicular helper T cells, naïve B cells, and naïve CD4⁺ T cells. Molecular docking and dynamics simulations supported the stable binding of key compounds to their target proteins, while ADMET predictions indicated favorable pharmacokinetic properties and safety profiles. Rat experiments demonstrated that ZLJYD significantly reduced blood pressure in spontaneously hypertensive rats, partially alleviated gut microbiota dysbiosis, and altered microbial community structure and phylogenetic diversity. CONCLUSION: This study systematically elucidates the potential mechanisms underlying the antihypertensive effects of ZLJYD through multiple components, targets, and pathways, particularly immune regulation and gut microbiota remodeling. These findings provide mechanistic insights into its potential therapeutic application.

16S rDNA sequencing↗

Stepwise allelic trajectory of ETP2 underlies trade-off between UVB tolerance and submergence adaptation in Arabidopsis thaliana.

Strong UVB radiation critically restricts plant growth, yield, and distribution, while mechanisms enabling adaptation to intense UVB remain unclear. Here, we uncover that the F-box ubiquitin E3 ligase UVBT1 (also known as ETP2) is indispensable for UVB tolerance in A. thaliana. In the high-altitude Tibet accession, a distinctive 166-bp deletion in ETP2 promoter leads to the complete absence of the W-box element, thereby eliminating WRKY36-mediated transcriptional repression. This results in elevated ETP2 levels, which degrade EIN2 and activate the protective anthocyanin/flavonoid pathway. Conversely, in low-altitude accessions, which are often exposed to lower UVB and higher precipitation conditions, WRKY36-mediated repression of ETP2 stabilizes EIN2 and WRKY22, endowing the plants with submergence tolerance. Notably, aside from the Tibet-accession-specific 166-bp deletion, the geographical distribution of the promoter allelic shift from C to G near the ETP2 W-box within the 166-bp region is tightly associated with UVB radiation with increasing altitudes for the other global accessions. This allelic change also enhances WRKY36-mediated repression of ETP2, suggesting an additional stepwise adaptation process. This work thus defines the WRKY36-ETP2-EIN2/WRKY22 module as a key regulator of UVB tolerance and submergence adaptation, potentially enabling A. thaliana to adapt to environments with varying UVB and precipitation conditions.

Arabidopsis↗

POFUT1 Serves as an Independent Prognostic Factor and Therapeutic Target by Activating the PI3K/AKT Pathway in Glioma.

OBJECTIVE: Protein O-fucosyltransferase 1 (POFUT1) has been implicated in several malignancies, but its functional and prognostic significance in glioma remains insufficiently defined. This study evaluated whether POFUT1 expression is associated with glioma progression, patient outcome, and PI3K/AKT pathway activity. METHODS: Public glioma transcriptome datasets from The Cancer Genome Atlas (TCGA) and Chinese Glioma Genome Atlas (CGGA) were analyzed and compared with clinical samples collected from 123 glioma patients. POFUT1 protein levels in clinical specimens were determined by immunohistochemical staining, and its association with patient outcome was analyzed using survival curves. In vitro, glioma cell growth, motility, and invasiveness were examined using MTT and Transwell assays. The effect of POFUT1 on tumor formation was further tested in a subcutaneous xenograft model. RNA sequencing, KEGG pathway enrichment, and pharmacological inhibition were then used to explore the mechanism linking POFUT1 to PI3K/AKT signaling. RESULTS: POFUT1 expression was higher in glioma than in normal brain tissue and increased with tumor grade. Patients with high POFUT1 levels had shorter overall survival, and multivariate Cox analyses supported POFUT1 as an independent prognostic indicator. Incorporating POFUT1 into a nomogram improved prediction of 1-, 3-, and 5-year survival. Functionally, POFUT1 knockdown reduced glioma cell growth, motility, invasion, and xenograft expansion, whereas POFUT1 overexpression produced the opposite phenotype. Transcriptomic and protein analyses indicated that POFUT1 enhanced PI3K/AKT signaling. The PI3K inhibitor LY294002 weakened the tumor-promoting effects caused by POFUT1 overexpression. CONCLUSION: POFUT1 as a key driver of glioma malignancy, predominantly through activating the PI3K-AKT signaling pathway. These findings highlight POFUT1 as a promising novel therapeutic target for aggressive glioma.

Glioma↗

Transcriptome analysis of the diseased intervertebral disc tissue in patients with spinal tuberculosis.

OBJECTIVE: To investigate the differential expression genes (DEGs) in spinal tuberculosis using transcriptomics, with the aim of identifying novel therapeutic targets and prognostic indicators for the clinical management of spinal tuberculosis. METHODS: Patients who visited the Department of Orthopedics at the Second Hospital, Lanzhou University from January 2021 to May 2023 were enrolled. Based on the inclusion and exclusion criteria, there were 5 patients in the test group and 5 patients in the control group. Total RNA was extracted and paired-end sequencing was conducted on the sequencing platform. After processing the sequencing data with clean reads and annotating the reference genome, FPKM normalization and differential expression analysis were performed. The DEGs and long non-coding RNAs (LncRNAs) were analyzed for Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) enrichment. The cis-regulation of differentially expressed mRNAs (DE mRNAs) by LncRNAs was predicted and analyzed to establish a co-expression network. RESULTS: This study identified 2366 DEGs, with 974 genes significantly upregulated and 1392 genes significantly downregulated. The upregulated genes are associated with cytokine-cytokine receptor interactions, tuberculosis, and TNF-α signaling pathways, primarily enriched in biological processes such as immunity and inflammation. The downregulated genes are related to muscle development, contraction, fungal defense response, and collagen metabolism processes. Analysis of LncRNAs from bone tuberculosis RNA-seq data detected a total of 3652 LncRNAs, with 356 significantly upregulated and 184 significantly downregulated. Further analysis identified 311 significantly different LncRNAs that could cis-regulate 777 target genes, enriched in pathways such as muscle contraction, inflammatory response, and immune response, closely related to bone tuberculosis. There are 51 genes enriched in the immune response pathway regulated by cis-acting LncRNAs. LncRNAs that regulate immune response-related genes, such as upregulated RP11-451G4.2, RP11-701P16.5, AC079767.4, AC017002.1, LINC01094, CTA-384D8.35, and AC092484.1, as well as downregulated RP11-2C24.7, may serve as potential prognostic and therapeutic targets. CONCLUSION: The DE mRNAs and LncRNAs in spinal tuberculosis are both associated with immune regulatory pathways. These pathways promote or inhibit the tuberculosis infection and development at the mechanistic level and play an important role in the process of tuberculosis transferring to bone tissue.

Humans↗

A functional SNP of interferon-gamma gene is important for interferon-alpha-induced and spontaneous recovery from hepatitis C virus infection.

Cytokine polymorphisms are associated with disease outcome and interferon (IFN) treatment response in hepatitis C virus (HCV) infection. We genotyped eight SNPs spanning the entire IFN-gamma gene in two cohorts and assessed the association between those polymorphisms and treatment response or spontaneous viral clearance. The first cohort was composed of 284 chronically HCV-infected patients who had received IFN-alpha-based therapy and the second was 251 i.v. drug users who had either spontaneously cleared HCV or become chronically infected. A SNP variant located in the proximal IFN-gamma promoter region next to the binding motif of heat shock transcription factor (HSF), -764G, was significantly associated with sustained virological response [P = 0.01, odds ratio (OR) = 2.66 [corrected] (confidence interval 1.3-5.6)[corrected]]. The association was independently significant in multiple logistic regression (P = 0.04) along with race, viral titer, and genotype. This variant was also significantly associated with spontaneous recovery [P = 0.04, OR = 3.51 (1.0-12.5)] in the second cohort. Functional analyses show that the G allele confers a two- to three-fold higher promoter activity and stronger binding affinity to HSF1 than the C allele. Our study suggests that the IFN-gamma promoter SNP -764G/C is functionally important in determining viral clearance and treatment response in HCV-infected patients and may be used as a genetic marker to predict sustained virological response in HCV-infected patients.

Alleles↗

Production of recombinant orange-spotted grouper (Epinephelus coioides) luteinizing hormone in insect cells by the baculovirus expression system and its biological effect.

The cDNA sequence encoding orange-spotted grouper lhb (LHbeta) and cga (GTHalpha) subunits were cocloned into baculovirus transfer vectors and expressed in insect Sf9 cells. The results showed that two bands of 15.6 kDa and 11.4 kDa could be detected by SDS-PAGE and a band of 30 kDa could be detected by native PAGE. The recombinant grouper Lh (rgLh) could stimulate the secretion of testosterone (T) and estradiol-17beta (E2) from the gonad in a static incubation system in a time-dependent, but not a dose-dependent, manner. Using in vivo bioassay, the mRNA levels of two aromatases (cyp19a1a [P450aromA] and cyp19a1b [P450aromB]), gnrh (GnRH), lhb, and cga in the pituitary, gonad, and hypothalamus were determined in different groups of orange-spotted groupers treated respectively with rgLh, human chorionic gonadotropin (hCG), and a culture medium of insect cells transformed with an expression vector without lhb and cga subunits. The mRNA levels of cyp19a1a and cyp19a1b rose dramatically after injecting rgLh intraperitoneally, which was consistent with the secretion of sex steroid hormones. Interestingly, the mRNA levels of gnrh dropped in the pituitary, hypothalamus, and gonad, and the mRNA levels of lhb and cga in the pituitary of the experimental group expressed at a higher level than that of the hCG group. These results are in accord with the long positive feedback loop of Lh on gonad sex steroid hormones and the short negative feedback loop of Lh on gnrh mRNA levels. These results indicate that the rgLh is successfully expressed by the baculovirus-insect expression system and that the rgLh has biological activity.

Animals↗

Ethanol augments elevated-[Ca2+]C induced trypsin activation in pancreatic acinar zymogen granules.

It has been long recognized that significant percentage of patients with acute pancreatitis often presents with a history of excessive alcohol consumption; however, the patho-physiological effect of ethanol on acute pancreatitis remains poorly understood. Abnormally elevated cytosolic Ca2+ ([Ca2+]C) has been found to be a shared phenomenon in acute pancreatitis that could induce trypsin premature activation. Here, we present the effects of ethanol to sensitize zymogen granules (ZGs) of pancreas acinar cells to elevated [Ca2+]C leading to zymogen premature activation that could result in acute pancreatitis. The pH fluctuations ([pH]G), Ca2+ concentration ([Ca2+]G), and premature trypsin activation inside the ZGs were monitored directly with specific fluorescence indicators. Our results showed that ethanol could act directly on ZGs and cause ZGs more receptive to elevated [Ca2+]C that could induce premature activation of zymogen (trypsin). This alcohol-induced effect is concentration dependent and strongly influenced by the surrounding [Ca2+]C. The K+ channels on ZGs membranes are required in the sensitization process. Our observations provide a mechanistic understanding of the role of ethanol in the initiation phase of alcoholic pancreatitis.

Animals↗

Autographa californica multiple nucleopolyhedrovirus nucleocapsid assembly is interrupted upon deletion of the 38K gene.

38K (ac98) of Autographa californica multiple nucleopolyhedrovirus (AcMNPV) is a highly conserved baculovirus gene whose function is unknown. To determine the role of 38K in the baculovirus life cycle, a 38K knockout bacmid containing the AcMNPV genome was generated through homologous recombination in Escherichia coli. Furthermore, a 38K repair bacmid was constructed by transposing the 38K open reading frame with its native promoter region into the polyhedrin locus of the 38K knockout bacmid. After transfection of these viruses into Spodoptera frugiperda cells, the 38K knockout bacmid led to a defect in production of infectious budded virus, while the 38K repair bacmid rescued this defect, allowing budded-virus titers to reach wild-type levels. Slot blot analysis indicated that 38K deletion did not affect the levels of viral DNA replication. Subsequent immunoelectron-microscopic analysis revealed that masses of electron-lucent tubular structures containing the capsid protein VP39 were present in cells transfected with 38K knockout bacmids, suggesting that nucleocapsid assembly was interrupted. In contrast, the production of normal nucleocapsids was restored when the 38K knockout bacmid was rescued with a copy of 38K. Recombinant virus that expresses 38K fused to green fluorescent protein as a visual marker was constructed to monitor protein transport and localization within the nucleus during infection. Fluorescence was first detected along the cytoplasmic periphery of the nucleus and subsequently localized to the center of the nucleus. These results demonstrate that 38K plays a role in nucleocapsid assembly and is essential for viral replication in the AcMNPV life cycle.

Animals↗

Characterization of Spodoptera exigua multicapsid nucleopolyhedrovirus ORF100 and ORF101, two homologues of E. coli ChaB.

ChaB, a putative regulator of ChaA in Escherichia coli (E. coli), and its homologues constitute a multigene family known to occur among bacteria, archaeabacteria and baculoviruses. The baculovirus Spodoptera exigua multicapsid nucleopolyhedrovirus contains two homologues of E. coli ChaB, open reading frames (ORFs) 100 (Se100) and 101 (Se101). RT-PCR and 5' RACE analyses indicated that transcription of both SeMNPV chaB genes occurs by 24 h postinfection and is initiated at a late consensus ATAAG motif. Immunoblot analysis showed that Se100 and Se101 were, respectively, expressed as 11 and 28kDa proteins in infected cells, and they were distributed in both cytoplasm and nucleus. Further analysis revealed that Se100 and Se101 are associated with nuclear structure and only present in the nucleocapsid of occlusion-derived virus. Additionally, column chromatography analysis showed that both proteins could weakly interact with nucleic acids. It was proposed that SeMNPV ChaB might function as DNA binding proteins.

Amino Acid Sequence↗

Hsp90 regulates activation of interferon regulatory factor 3 and TBK-1 stabilization in Sendai virus-infected cells.

Interferon regulatory factor 3 (IRF3) plays a crucial role in mediating cellular responses to virus intrusion. The protein kinase TBK1 is a key regulator inducing phosphorylation of IRF3. The regulatory mechanisms during IRF3 activation remain poorly characterized. In the present study, we have identified by yeast two-hybrid approach a specific interaction between IRF3 and chaperone heat-shock protein of 90 kDa (Hsp90). The C-terminal truncation mutant of Hsp90 is a strong dominant-negative inhibitor of IRF3 activation. Knockdown of endogenous Hsp90 by RNA interference attenuates IRF3 activation and its target gene expressions. Alternatively, Hsp90-specific inhibitor geldanamycin (GA) dramatically reduces expression of IRF3-regulated interferon-stimulated genes and abolishes the cytoplasm-to-nucleus translocation and DNA binding activity of IRF3 in Sendai virus-infected cells. Significantly, virus-induced IRF3 phosphorylation is blocked by GA, whereas GA does not affect the protein level of IRF3. In addition, TBK1 is found to be a client protein of Hsp90 in vivo. Treatment of 293 cells with GA interferes with the interaction of TBK1 and Hsp90, resulting in TBK1 destabilization and its subsequent proteasome-mediated degradation. Besides maintaining stability of TBK1, Hsp90 also forms a novel complex with TBK1 and IRF3, which brings TBK1 and IRF3 dynamically into proximity and facilitates signal transduction from TBK1 to IRF3. Our study uncovers an essential role of Hsp90 in the virus-induced activation of IRF3.

Animals↗

Computed tomography for imaging the breast.

Despite the success of screening mammography contributing to the reduction of cancer mortality, a number of other imaging techniques are being studied for breast cancer screening. In our laboratory, a dedicated breast computed tomography (CT) system has been developed and is currently undergoing patient testing. The breast CT system is capable of scanning the breast with the woman lying prone on a tabletop, with the breast in the pendant position. A 360 degrees scan currently requires 16.6 s, and a second scanner with a 9-second scan time is nearly operational. Extensive effort was placed on computing the radiation dose to the breast under CT geometry, and the scan parameters are selected to utilize the same radiation dose levels as two-view mammography. A total of 55 women have been scanned, ten healthy volunteers in a Phase I trial, and 45 women with a high likelihood of having breast cancer in a Phase II trial. The breast CT process leads to the production of approximately three hundred 512 x 512 images for each breast. Subjective evaluation of the breast CT images reveals excellent anatomical detail, good depiction of microcalcifications, and exquisite visualization of the soft tissue components of the tumor when contrasted against adipose tissues. The use of iodine contrast injection dramatically enhances the visualization of tumors. While a thorough scientific investigation based upon observer performance studies is in progress, initial breast CT images do appear promising and it is likely that breast CT will play some role in breast cancer imaging.

Breast↗

Identification of Spodoptera litura multicapsid nucleopolyhedrovirus ORF97, a novel protein associated with envelope of occlusion-derived virus.

Open reading frame (ORF) 97 of Spodoptera litura multicapsid nucleopolyhedrovirus (Splt97) is a member of 11k gene family (InterPro database accession number: IPR009313) in insect viruses, potentially encoding 112 amino acids with a predicted molecular weight of 13.2 kDa. Sequence analysis indicated that Splt97 has 8-50% amino acid identity with the homologues of other known baculoviruses including Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV) ORF108. Splt97 transcription in SpltMNPV-infected Spli-221 cells was detected from 6 to 96 h postinfection (p.i.) and the mRNA start site was mapped within a consensus baculovirus early promoter motif (ACATT). Time course of Splt97 expression in SpltMNPV-infected cells showed that Splt97 was expressed from 48 through 96 h p.i. as a 13 kDa protein. Western blot analysis revealed that Splt97 was present in occlusion-derived virus (ODV). Furthermore, when ODV was fractionated into nucleocapsid and envelope components, Splt97 was shown to be present only in the envelope. These results suggested that Splt97 was a baculovirus ODV-associated protein.

Amino Acid Sequence↗

A geometric calibration method for cone beam CT systems.

Cone beam CT systems are being deployed in large numbers for small animal imaging, dental imaging, and other specialty applications. A new high-precision method for cone beam CT system calibration is presented in this paper. It uses multiple projection images acquired from rotating point-like objects (metal ball bearings) and the angle information generated from the rotating gantry system is also used. It is assumed that the whole system has a mechanically stable rotation center and that the detector does not have severe out-of-plane rotation (<2 degrees). Simple geometrical relationships between the orbital paths of individual BBs and five system parameters were derived. Computer simulations were employed to validate the accuracy of this method in the presence of noise. Equal or higher accuracy was achieved compared with previous methods. This method was implemented for the geometrical calibration of both a micro CT scanner and a breast CT scanner. The reconstructed tomographic images demonstrated that the proposed method is robust and easy to implement with high precision.

Algorithms↗

[A comparative study of unrelated donor bone marrow transplantation and peripheral blood stem cell transplantation for their therapeutic effects on leukemia].

OBJECTIVE: To compare the effect of unrelated donor bone marrow (BM) transplantation and peripheral blood stem cell (PBSC) transplantation in light of hemopoietic reconstitution, immune reconstitution, infection, incidence of graft-versus-host disease (GVHD) and other complications in patients with leukemia. METHODS: The clinical outcomes of 16 patients receiving unrelated PBSC graft mobilized by granulocyte colony-stimulating factor (G-CSF) were compared with 30 patients receiving unrelated BM transplantation. RESULTS: Engraftment was achieved in 97.83% of the total patients. Compared with BM transplantation group, PBSC graft contained significantly more nucleated cells (P=0.000), resulting in a significantly shorter time-to-neutrophil (16.21-/+3.09 vs 12.81-/+4.15 days, P=0.003) and platelet engraftment (20.31-/+7.19 vs 15.50-/+6.91 days, P=0.035). T cell reconstitution differed little between the two groups at different time points after transplantation. The incidences of early-stage infection were 37.50% and 50.00% (P=0.644) in the PBSC and BM groups, respectively. In PBSC and BM groups, the incidences of grades I to IV acute GVHD (aGVHD) were 56.25% and 70.00% (P=0.456), 18.75% and 13.79% (P=0.661) for grades III to IV aGVHD, and 30.77% and 36.36% (P=0.413) for chronic GVHD (cGVHD), respectively. The nonrelapse transplant-related mortality (TRM) rates were 18.75% in PBSC group and 33.33% in BM group (P=0.295). The relapse occurred in 18.75% and 6.90% (P=0.226) of the patients in the two groups, respectively, and the 2-year disease-free survival (DFS) rates were 62.19% and 56.23% (P=0.615), respectively. CONCLUSION: G-CSF-mobilized PBSCs allow more rapid engraftment in unrelated donor recipients in comparison with conventional BM, but T cell reconstitution and the incidence of infection between the two groups differ little, nor are there significant differences in the incidence or severity of aGVHD and cGVHD, nonrelapse TRM or 2-year DFS rates between the two groups.

Adolescent↗

[Determination of 27 microelements in 11 shellfishes].

Shellfish samples were prepared by microwave, and 27 microelements including Ca, Mg, K, Na, P, S, Zn, Mn, Fe, Cu, Cr, Co, Se, Sn, Ni, Al, Ti, V, Mo, Ba, Ge, Si, Cd, I, Pb, As and Hg were determined by ICP-AES. It was showed that ICP-AES had an obvious advantage in the determination of microelements, and shellfishes contained upwards of 20 kinds of microelements. Calcium in fresh water was higher than that in seawater, and As and Pb were the major pollutants.

Arsenic↗

[Comparison of clinical outcomes between unrelated donor peripheral blood stem cell transplantation and bone marrow transplantation for leukemia].

OBJECTIVE: To compare the hemopoietic reconstitution, immune reconstitution, infection, incidence of graft-versus-host disease (GVHD) and clinical outcome between unrelated donor peripheral blood stem cell (PBSC) transplantation and bone marrow (BM) transplantation for leukemias. METHODS: The clinical results of 21 leukemia patients receiving G-CSF mobilized PBSC graft from unrelated donors were compared with that of 32 patients receiving unrelated BM transplants. RESULTS: Compared with BM grafts, the PBSC graft contained significantly more nucleated cells (P = 0.000), and resulted in a significantly shorter time-to-neutrophil (12.43 +/- 3.67 vs 16.16 + 2.99 days) and platelet engraftment (14.67 +/- 6.19 vs 21.23 +/- 8.25 days), (P = 0.000 and 0.003, respectively). T cell reconstitution between the two groups differed little after transplantation. The incidences of early-stage infection (42.86% vs 53.13%), the probabilities of acute graft-versus-host disease (aGVHD) (61.90% vs 71.88%), the grades III to IV aGVHD (23.81% vs 15.63%), the chronic GVHD (47.06% vs 43.48%) and the probabilities of relapse (6.90% vs 12.50%) between PBSC and BM groups all has no statistical significance (NS). The 2-year disease free survival (DFS) rates of the two groups were (50.14 +/- 12.00) % and (59.81 +/- 8.99)%, respectively also have no NS. CONCLUSION: G-CSF-mobilized unrelated donor PBSCs engraft more rapidly in the recipients as compared with conventional BM grafts. The T cell reconstitution, the incidence of infection, the incidence and severity of aGVHD and cGVHD, and the 2-year DFS rates between the two groups all have no significant differences.

Adolescent↗

Characterization of Spodoptera litura multicapsid nucleopolyhedrovirus 38.7 k protein, which contains a conserved BRO domain.

Homology analysis revealed that Spodoptera litura multicapsid nucleopolyhedrovirus (SpltMNPV) 38.7 k protein has 22-83% amino acid identities with Ecotropis obliqua NPV, Mamestra configurata MNPV, Helicoverpa armigera SNPV, H. zea SNPV, S. exigua MNPV and S. littoralis MNPV 38.7 k proteins. Analysis of the relationship of these 38.7 k proteins indicated that they contain a conserved BRO-N domain, and SpltMNPV and SpliMNPV 38.7 k proteins also contain a motif found in all known viral and prokaryotic single-strand DNA binding proteins. RT-PCR results showed that SpltMNPV 38.7 k gene is transcribed actively at the late stage of infection and the mRNA start site was mapped within a consensus baculovirus late promoter motif (ATAAG). Western blot analysis revealed that the 38.7 k was expressed in infected S. litura cells as a 41 kDa form and this protein distributed in the nucleus of infected cells. Using a histone extraction protocol, SpltMNPV 38.7 k could be detected in the histone H1 fraction. Micrococcal nuclease treatment released SpltMNPV 38.7 k protein from the chromatin fraction, suggesting that its involvement in nucleosome structures. Furthermore, column chromatography using DNA-cellulose showed that SpltMNPV 38.7 k protein interacted with nucleic acids. It was proposed that SpltMNPV 38.7 k might function as a DNA-binding protein.

Amino Acid Motifs↗