Phylogenetic Relationship of the Firefly,Diaphanes pectinealis(Insecta,Coleoptera,Lampyridae) Based on DNA Sequence and Gene Structure of Luciferase

Diaphanes is the fourth largest genus in Lampyridae, but no luciferase gene from this genus has been reported. In this paper, by PCR amplification of the genomic DNA, the luciferase gene of Diaphanes pectinealis, which is the first case from Diaphanes, was identified and sequenced. The luciferase gene from D. pectinealis spans 1958 base pairs （bp） from the start to the stop codon, including seven exons separated by six introns, and encoding a 547-residuelong polypeptide. Its deduced amino acid sequence showed high protein similarity to those of the Lampyrini tribe （93 - 94% ） and the Cratomorphini tribe （92%）, while low similarity was found with the North American firefly Photinus pyralis （83%） of the Photinini tribe within the same subfamily Lampyrinae. The phylogenetic analysis performed with the deduced amino acid sequences of the luciferase gene further confirms that D. pectinealis, Pyrocoelia, Lampyris, Cratomorphus, and Photinus belong to the same subfamily Lampyrinae, and Diaphanes is closely related to Pyrocoelia, Lampyris, and Cratomorphus. Furthemore, the phylogenetic analysis based on the nucleotide sequences of the luciferase gene indicates Diaphanes is a sister to Lampyris. The phylogenetic analyses are partly consistent with morphological （Branham ＆ Wenzel, 2003） and mitochondrial DNA analyses （Li et al, 2006）.

Cloning,Expression and Sequence Analysis of A Luciferase Gene from the Chinese Firefly Pyrocoelia pygidialis

The cDNA encoding the luciferase from lantern mRNA of one diurnal firefly Pyrocoelia pygidialis Pic, 1926 has been cloned, sequenced and functionally expressed. The cDNA sequence of P pygidialis luciferase is 1647 base pairs in length, coding a protein of 548 amino acid residues. Sequence analysis of the deduced amino acid sequence showed that this luciferase had 97.8% resemblance to luciferases from the fireflies Lampyris noctiluca, Lampyris turkestanicus and Nyctophila cf. caucasica. Phylogenetic analysis using deduced amino acid sequence showed that P pygidialis located at the base of Lampyris＋Nyctophila clade with robust support （BP=97%）; but did not show a monophyletic relationship with its congeneric species P pectoralis, P tufa and P miyako, all three are strong luminous and nocturnal species. The expression worked in recombinant Escherichia coli. Expression product had a 70kDa band and emitted yellow-green luminescence in the presence of luciferin. Five loops in the P pygidialis luciferase, L1 （NI98-G208）, L2 （T240-G247）, L3 （G317-K322）, L4 （L343-I350） and L5 （G522-D532）, were found from the structure modeling analysis in the cleft, where it was considered the active site for the substrate compound entering and binding. Different amino acid residues between the luciferases of P. pygidialis and the three other known strong luminous species can not explain the situation of weak or strong luminescence. Future study of these loops, residues or crystal structure analysis may be helpful in understanding the real differences between the luciferases between diurnal and nocturnal species.

RCAS(J)-Luciferase重组病毒拯救及其相关生物学功能鉴定

RCAS载体系列是基于A型罗斯肉瘤病毒(RSV-A)所改造而成的反转录病毒感染性克隆,转染易感细胞后,能够产生高滴度的RSV-A病毒。同时,RCAS载体可携带外源基因进入靶细胞,从而进行蛋白的高效表达。为了获取滴度高且易于检测的RSV,进行ALV-J受体方面的研究,本研究将RCAS(A)-GFP载体中RSV-A的囊膜蛋白基因替换为ALV-J的囊膜蛋白基因,并将绿色荧光蛋白报告基因(gfp)替换为海参荧光素酶(luciferase)报告基因,构建带有luciferase报告基因的囊膜蛋白为ALV-J囊膜蛋白的RSV重组病毒。经验证,本研究所构建的重组病毒,与传统的ALV-J株相比,具有复制能力强,病毒滴度高等优点,而且能够通过ALV-J特异性受体ch NHE1感染ALV-J非允许细胞系,有利于病毒感染初期的检测和定量,为病毒与其受体之间相互作用的研究奠定了基础。

Tet-on控制的Luciferase和SupF突变报告基因质粒的构建及其在顺铂致突变作用中的应用研究

目的研究TCR在顺铂导致的细胞内DNA损伤和突变过程中的分子机制,并为进一步研究转录偶联修复与突变发生的分子机制提供重要分子生物学依据。方法首先将SupF突变报告基因克隆到带有双向真核启动子的含有Tet调控元件TRE的表达载体pBI-L的多克隆位点(MCS)上,获得pTCR-1,再将SV40ori元件插入pTCR-1载体,最终获得pTCR-2质粒。酶切和DNA测序证实后,用顺铂将pTCR-2进行体外DNA损伤后瞬时转染至Tet-on293细胞,在Dox诱导下培养48h,从细胞内提取质粒,纯化后转化SY204菌株,蓝白斑筛选挑取白色突变斑,计算突变频率并进行DNA测序检测突变频谱。结果经酶切鉴定和测序分析,插入片段长度和序列正确。在Dox诱导下取得了SupF报告基因在转录偶联修复途径中的突变频率与频谱。结论重组的pTCR-2质粒具有在真核细胞中Tet启动的转录活性,应用于顺铂致突变研究中,使转录条件下的突变情况能够得以反映。

表达Renilla Luciferase重组流感病毒的构建及生物学特性研究

本研究构建了表达Renilla Luciferase的重组流感病毒,并运用Luciferase报告基因检测系统对该病毒的生物学特性进行了研究。研究发现该病毒复制时能稳定表达Renilla Luciferase,添加磷酸奥斯他韦抑制病毒复制后Luciferase表达量明显低,而且表达量与磷酸奥司他韦浓度成反比。结果表明检测Luciferase表达量可以直接反应病毒的复制,将该重组病毒与Luciferase报告基因系统运用到抗流感药物的大规模筛选中,可为抗流感药物的筛选提供一种快速且灵敏的检测方法。

Improvement of Chemically-activated Luciferase Gene Expression Bioassay for Detection of Dioxin-Iike Chemicals

Objective To improve the chemically-activated luciferase expression (CALUX)bioassay for detection of dioxin-like chemicals (DLCs) based on the toxicity mechanisms ofDLCs. Method A recombinant vector was constructed and used to transfect humanhepatoma (HepG2). The expression of this vector was 10-100 folds higher than that of pGL2used in previous experiments. The transfected cells showed aromatic hydrocarbon receptor(AhR)-meditated luciferase gene expression. The reliability of luciferase induction in thiscell line as a reporter of AhR-mediated toxicity was evaluated, the optimal detection timewas examined and a comparison was made by using the commonly used ethoxyresoufin-O-deethylase (EROD) activity induction assay. Result The results suggested that theluciferase activity in recombinant cells was peaked at about 4 h and then decreased to astable activity by 14 h after TCDD treatment. The detection limit of this cell line was0.11pmol/L, or 10-fold lower than in previous studies, with a linear range from 1 to 100pmol/L, related coefficient of 0.997, and the coefficient of variability (CV) of 15-30%.Conclusion The luciferase induction is 30-fold more sensitive than EROD induction, thedetection time is 68 h shorter and the detection procedure is also simpler.

Effects of Ionic Surfactants on Bacterial Luciferase and α-Amylase

In order to study the effects of ionic surfactants on bacterial luciferase,the cationic surfactant dodecyltrimethylammonium biomide (DTAB) and anionic surfactant sodium dodecylsulfate (SDS) were chosen.For comparison with bacterial luciferase,α-amylase was used since these two enzymes have similar electrostatic potential and charged active sites.After the enzymes were treated with the surfactants,the catalytic properties of bacterial luciferase andα-amylase were assayed,and fluorescence spectroscopy and circular dichroism (CD) were used to analyze the alteration of the protein structure.The results showed that when the DTAB concentration was low,the cationic surfactant DTAB enhanced the enzymatic activities of bacterial luciferase andα-amylase.On the other hand,the anionic surfactant SDS did not alter the enzymatic activity.The main interaction of cationic surfactant DTAB and the negatively charged surface of the proteins was the ionic interaction,which could alter the environment for the enzyme to work when the DTAB/enzyme molar ratio was low.However,at high cationic surfactant concentration,the ionic interaction and hydrophobic interaction might destroy the secondary and tertiary structures of the proteins,leading to the loss of enzymatic activities.

Monitoring of prostate cancer growth and metastasis using a PSA luciferase report plasmid in a mouse model

Objective:To construct a PSA luciferase report plasmid and monitor the growth and metastasis of prostate cancer after emasculation in SCID mice.Methods:PSA promoter sequence and luciferase gene were amplified by PCR and subsequently inserted into pZsCreen1-1 vector to construct pPSA-FL-Luc vector.LNCaP cells that were stably transfected with pPSA-FL-Luc were used to establish a SCID mouse xenograft model.Then,the growth and metastasis of prostate cancer were monitored via living imaging.Results:We successfully constructed a PSA luciferase piasmid,pPSA-FL-Luc.DHT enhanced lucifcrase activity in a concentration-dependent manner in 293 T cells with pPSA-FL-Luc transfection.Prostate cancer SCID mouse model was established with pPSA-FL-Luc transfected LNCaP cells.In tumor bearing mice with or without emasculation,pPSA-FL-Lue piasmid was applied to monitored tumor growth and metastasis based on bioluminescence imaging.Conclusions:We construct a pPSA-FL-Luc piasmid,which stably expresses luciferase and can be applied to monitor tumor development in a prostate SCID mouse model.

Construction of a replication-competent hepatitis B virus vector carrying secreted luciferase transgene and establishment of new hepatitis B virus replication and expression cell lines

BACKGROUND Previously,we have successfully constructed replication-competent hepatitis B virus(HBV)vectors by uncoupling the P open reading frame(ORF)from the preC/C ORF to carefully design the transgene insertion site to overcome the compact organization of the HBV genome and maintain HBV replication competence.Consequently,the replication-competent HBV vectors carrying foreign genes,including pCH-BsdR,carrying blasticidin resistance gene(399 bp),and pCH-hrGFP,carrying humanized renilla green fluorescent protein gene(720 bp),were successfully obtained.However,the replication efficiency of the former is higher but it is tedious to use,while that of the latter is poor and cannot be quantified.Hence,we need to search for a new reporter gene that is convenient and quantifiable for further research.AIM To establish a helpful tool for intracellular HBV replication and anti-viral drugs screening studies.METHODS We utilized the replication-competent HBV viral vectors constructed by our laboratory,combined with the secreted luciferase reporter gene,to construct replication-competent HBV vectors expressing the reporter gene secretory Nanoluc Luciferase(SecNluc).HepG2.TA2-7 cells were transfected with this vector to obtain cell lines with stably secreted HBV particles carrying secNluc reporter gene.RESULTS The replication-competent HBV vector carrying the SecNluc reporter gene pCHsNLuc could produce all major viral RNAs and a full set of envelope proteins and achieve high-level secreted luciferase expression.HBV replication intermediates could be produced from this vector.Via transfection with pTRE-sNLuc and selection by hygromycin,we obtained isolated cell clones,named HBV-NLuc-35 cells,which could secrete secNLuc recombinant viruses,and were sensitive to existing anti-HBV drugs.Using differentiated HepaRG cells,it was verified that recombinant HBV possessed infectivity.CONCLUSION Our research demonstrated that a replication-competent HBV vector carrying a secreted luciferase transgene possesses replication and expression ability,and the established HBV replication and expression cell lines could stably secrete viral particles carrying secNluc reporter gene.More importantly,the cell line and the secreted recombinant viral particles could be used to trace HBV replication or infection.

Preparation of recombinant firefly luciferase by a simple and rapid expression and purification method and its application in bacterial detection

A simple and rapid expression and purification method of recombinant firefly luciferase was developed for bacteria detection. A modified luciferase gene from North American firefly Photinus pyralis was cloned into pET28a expression vector and the recombinant protein was produced in Escherichia coli BL21. The recombinant luciferase,equipped with a polyhistidine affinity tag,was purified by immobilized metal ion affinity chromatography (IMAC). The approach generated an abundant expression and an efficient purification of a recombinant luciferase with final yield 1.995mg/L of cell culture. Experiments on the recombinant luciferase also showed that the relative light units (RUL) of the enzyme were 5.8×108,and the specific activity was 2.9×1010 RLU/mg. By applying adenosine triphosphate (ATP) bioluminescence to detection of the coin bacteria using the recombinant protein,the ATP content of bacteria was 9.48×10-16mol/mL,and was identical to the bacteria counts (4500CFU/mL) in order of magnitude. Taken together,our results provided a simple and efficacious method of the preparation of recombinant luciferase,which could be applied in the determination of bacteria via ATP bioluminescence.

A Quantitative Assay for Measuring of Bovine Immunodeficiency Virus Using a Luciferase-based Indicator Cell Line

In order to quantitate the bovine immunodeficiency virus line （BIVL） was established by transfecting baby hamster kidney （BIV） cells infection in vitro, a BIV indicator cell with reporter plasmids containing the firefly luciferase gene driven by a BIV long terminal repeat promoter. The BIV activates promoter activity of the LTR to express luciferase upon infection. BIV infection could therefore by quantified by detection of luciferase activity. Compared to standard assays used to detect BIV infection, the BIVL-based assay is 10 times more sensitive than the the CPE-based assay, and has similar sensitivity with the viral capsid protein Western blot assay BIV indicator cell line could detect BIV infection specifically. Luciferase activity of BIV infected BIVL cells showed a time dependent manner, and 60 h post infection is the optimal time to detect BIV infection. Luciferase activity of BIVL cells correlates with the BIV capsid protein expression. Moreover, a linear relationship was found between MOI and the activated intensity of luciferase expression. In brief, the BIV indicator cell line is an easy, robust and quantitive method for monitoring BIV infection.

Gaussia Luciferase Reporter Assay for Assessment of Gene Delivery Systems in Vivo

Objective To develop an alternative method for assessment of gene delivery systems in vivo.Methods Mouse primary spleen lymphocytes were genetically modified in vitro by a retroviral vector harboring a Gaussia luciferase(Gluc) expression cassette.After implantation of these cells into recipient mice,the expression of Gluc was detected in whole blood or plasma collected.Results As little as 10 μL whole blood drawn from the recipient mice could guarantee prompt reading of Gluc activity with a luminometer.And the reading was found in good correlation with the number of genetically modified spleen lymphocytes implanted to the mice.Conclusions Gluc may be useful as an in vivo reporter for gene therapy researches,and Gluc blood assay could provide an alternative method for assessment of gene delivery systems in vivo.

Fiber optic biosensor of immobilized firefly luciferase

Luciferase from firefly lantern extract was immobilized on CNBr activated Sepharose 4B. The kinetic properties of immobilized luciferase were extensively studied. The K m′ for D luciferin is 11.9 μmol/L, the optimum pH and temperature for Sepharose bound enzyme were 7.8 and 25℃ respectively. A luminescence fiber optic biosensor, making use of immobilized crude luciferase, was developed for assay of ATP. The peak light intensity was linear with respect to ATP concentration in range of 10 -9 -10 -5 mol/L. A biological application was also demonstrated with the determination of serum ATP from rats bred in low versus normal oxygen environments.

3' Noncoding Region Construction of GHR Gene-luciferase Report Vector and Valuation

To analyze miR-139 target sites in 3＇ UTR of GHR gene in dairy cow mammary gland, a GHR 3＇ UTR- luciferase reporter vector was constructed and the effect of miRNA on its activity was evaluated in dairy cow mammary gland epithelial cells （DCMECs）. The miR-139 targeting GHR 3＇ UTR was predicted by Target Scan 5.1 software, 3＇ UTR fragment of GHR was amplified by PCR from RNA of DCMECs. PCR products were cloned into Spe Ⅰ/Hind Ⅱ modified pMIR-Report vector. The luciferase reporter vector and miRNA eukaryotic expression vector were transferred into DCMECs using lipofectamine 2000 transfection reagent. The dualluciferase reporter assay system was used to quantitiate the reporter activity. The results showed that a 107 bp 3＇ UTR fragment of GHR gene was successfully cloned into the pMIR-Report vector, which authenticated by Spe Ⅰ/Hind Ⅲ digestion and DNA sequencing. The luciferase activity of reporter construction treated with miR-139 decreased 20.87% compared with the control group. It was concluded that the GHR3＇ UTR-luciferase reporter vector had been successfully constructed. The luciferase activity of the reporter could be suppressed by miR- 139.

Measurement of AhR Ligands in the Tissues of Colon Cancer Patients with XRE Luciferase Reporter

The Aryl hydrocarbon receptor(AhR)ligands exhibiting modulating activity represents a new class of anticancer agents that can be directed towards several tumors.We have examined AhR expression in human colon cancer and adjacent non-tumor tissue.AhR expression level was about 2-7 times higher in tumor tissue samples than in the adjacent non-tumor samples(in 82%of all the samples).We were unable to find any increase of ABCG2 expression on the level of the transcription,while the expression of MDR2 was increased in half of the tumors compared to the levels of expression in normal adjacent tissue.We have used FICZ as a potent high affinity ligand of the AhR to calibrate the reporter cell line HEK293TAhR-luc as a potent high affinity ligand of the AhR.The concentration of xenobiotic response element(XRE)ligands is higher,than in the blood of healthy people in 86%of the patients.The proposed test system will allow the use of the AhR ligand level as an additional diagnostic marker in the treatment of colon cancer.

An Accurate Model for the Expression of the Antisense RNA Block Gene:the Firefly Luciferase Gene-Xenopus Oocyte System

The plasmid p^(SV-Luc20)or the mRNA of luciferase gene transcribed from p^(SP64-Luc12)was introduced intothe nucleus or cytoplasm of Xenopus oocytes at stages 5-6 by microinjection.Then the injectedoocytes were incubated in MB medium at 18℃ for definite periods,and the crude enzyme ofluciferase was prepared.Results indicated that the luciferase gent and its mRNA could be transcribedand translated into the enzymatic protein of luciferase with high biological activity,and could alsocatalyze the substrates to emit light.If different ratios of firefly lucifcrasc gene and its antisense RNA were introduced together into thenucleus or cytoplasm of Xenopus oocytes,then the expression of firefly luciferase gone was severelyblocked.Since the lucifcrasc activity can be measured rapidly and quantitatively and the Xenopusoocytes obtained easily,the firefly luciferase gene-Xenopus oocyte system is an excellent model forrevealing quantitatively how the antisense RNA can block gene expression.

Construction of coxsackievirus B5 viruses with luciferase reporters and their applications in vitro and in vivo

Coxsackievirus belongs to the Picornaviridae family and is one of the major pathogens that cause hand,foot and mouth disease(HFMD)in infants and children with potential serious complications and even deaths.The pathogenesis of this virus is not fully elucidated and no vaccine or antiviral drug has been approved.In this study,a full-length infectious cDNA clone of coxsackievirus B5 virus was assembled and the recombinant virus displayed similar growth kinetics and ability to cause cytopathic effects as the parental virus.Luciferase reporter was then incorporated to generate both full-length and subgenomic replicon(SGR)reporter viruses.The full-length reporter virus is suitable for high-throughput antiviral screening,while the SGR is a useful tool to study viral-host interactions.More importantly,the full-length reporter virus has also been shown to infect the suckling mouse model and the reporter gene could be detected using an in vivo imaging system,thus providing a powerful tool to track viruses in vivo.In summary,we have generated coxsackievirus B5 reporter viruses and provided unique tools for studying virus-host interactions in vitro and in vivo as well as for high-throughput screenings(HTS)to identify novel antivirals.

Study on the regulatory effect of liver X receptor in HEK293 cells by six main diterpene esters in Semen Euphorbiae

Background:To study the effects of the main diterpene esters in Euphorbia factor L_(1),L_(2),L_(3),L_(7a),L_(7b)and L_(8)on the transcriptional activity and protein expression of liver X receptor(LXR).Methods:The effect of the main diterpene ester components in Semen Euphorbiae on the viability of HEK293 cells were studied by MTT assay.The LXR-Luc plasmid vector was transfected into HEK293 cells and treated with Euphorbia factor L_(1),L_(2),L_(3),L_(7a),L_(7b)and L_(8)for 24 h.The effect of the main diterpene ester components of Semen Euphorbiae on LXR-Luc luciferase activity was investigated by dual luciferase reporter gene system,and the expression of LXRαprotein was detected by Western Blot.Results:Euphorbia factor L_(1),L_(2),L_(3),L_(7a),L_(7b)and L_(8)could significantly reduce the relative luciferase activity(RLU)of LXRα,and the expression level of LXRαprotein was significantly down-regulated.Conclusion:Euphorbia factor L_(1),L_(2),L_(3),L_(7a),L_(7b)and L_(8)can inhibit the expression of LXR protein level,which may be achieved by inhibiting the transcriptional activity of LXR.

Tumorigenesis and spontaneous metastasis by luciferase-labeled human xenograft osteosarcoma cells in nude mice

Background Osteosarcoma （OS） is the most common primary malignant tumor of bone. Mouse models of human OS can invariably provide greater insight into the complex mechanisms that underlie the development and pathogenesis of this aggressive tumor. Bioluminescence technology favored tracing cancer cells in vivo. In this study, an OS model was described and evaluated using human OS cell line, Saos2, labeled with luciferase （Saos2-1uc）. Methods Saos2 cells were infected by lentivirus loading a firefly luciferase gene. Luciferase expression of Saos2-1uc cells was characterized both in vitro and in vivo. Specific biologic and oncologic features of Saos2-1uc cells were analyzed. The OS was established as orthotopic xenografts in nude mice. Both orthotopic tumors and spontaneous lung metastasis were analyzed. Results Tumorigenesis and spontaneous lung metastasis in nude mice could be monitored in vivo through in vivo imaging system. The enhancement in proliferation, migration and invasion abilities and the attenuation in adhesion ability were observed in Saos2-1uc cells compared with Saos2 cells. Furthermore, there were the up-regulation of Osteocalcin, CCRIO, CXCR1 and ID1 and the down-regulation of ALP, collagen I, CCR1, CCR3, CXCR3, NID and N-cadherin in Saos2-1uc cells compare to Saos2 cells. The rate of spontaneous lung metastasis in Saos2-1uc cells was higher than that in Saos2 cells, although without significant difference. Conclusions Lentivirus transfection may cause alteration of gene expression profiles and further biological functions. This model can be used in the elucidation of molecular mechanisms of tumorigenesis and the screening of new therapeutic agents.

Validation and invalidation of SARS-CoV-2 main protease inhibitors using the Flip-GFP and Protease-Glo luciferase assays

SARS-CoV-2 main protease(M^(pro))is one of the most extensively exploited drug targets for COVID-19.Structurally disparate compounds have been reported as M^(pro) inhibitors,raising the question of their target specificity.To elucidate the target specificity and the cellular target engagement of the claimed M^(pro) inhibitors,we systematically characterize their mechanism of action using the cell-free FRET assay,the thermal shift-binding assay,the cell lysate Protease-Glo luciferase assay,and the cell-based FlipGFP assay.Collectively,our results have shown that majority of the M^(pro) inhibitors identified from drug repurposing including ebselen,carmofur,disulfiram,and shikonin are promiscuous cysteine inhibitors that are not specific to M^(pro),while chloroquine,oxytetracycline,montelukast,candesartan,and dipyridamole do not inhibit M^(pro) in any of the assays tested.Overall,our study highlights the need of stringent hit validation at the early stage of drug discovery.