c-Myc protein encoded by c-Myc (cellular-myelocytomatosis viral oncogene) gene regulates the related gene expression through the Wnt/β-catenin signaling pathway, and has received extensive attention in recent years. The purpose of this study was to express Helicoverpa armigera c-Myc gene (Ha-c-Myc) by using prokaryotic expression system, prepare the polyclonal antibody, examine the spatio-temporal expression profile of Ha-c-Myc, and investigate the possible function of Ha-c-Myc in regulating H. armigera sterol carrier protein-2 (SCP-2) gene expression. The Ha-c-Myc gene was amplified by PCR and cloned into a prokaryotic expression plasmid pET-32a(+). The recombinant plasmid pET-32a-Ha-c-Myc was transformed into Escherichia coli BL21. IPTG was used to induce the expression of the recombinant protein. Protein was purified by Ni²⁺-NTA column and used to immunize New Zealand rabbits for preparing the polyclonal antibody. The Ha-c-Myc expression levels in different developmental stages (egg, larva, prepupa, pupa, and adult) of H. armigera and different tissues (midgut, fat body, head, and epidermis) of the prepupa were determined by real-time quantitative reverse transcription PCR (qRT-PCR). Ha-c-Myc siRNA was synthesized and transfected into H. armigera Ha cells. The relative mRNA levels of Ha-c-Myc and HaSCP-2 in Ha cells were detected by qRT-PCR. Results showed that the pET-32a-Ha-c-Myc recombinant plasmid was constructed. The soluble Ha-c-Myc protein of about 65 kDa was expressed in E. coli. The polyclonal antibody was prepared. Western blotting analysis suggested that the antibody had high specificity. Enzyme linked immunosorbent assay (ELISA) showed that the titer of the antibody was high. Ha-c-Myc gene expressed at all developmental stages, with high levels in the early and late instars of larva, and the prepupal stage. Tissue expression profiles revealed that Ha-c-Myc expressed in various tissues of prepupa, with high expression level in the midgut, but low levels in the epidermis and fat body. RNAi results showed that the knockdown of Ha-c-Myc expression significantly affected transcription of HaSCP-2, leading to a 50% reduction in HaSCP-2 mRNA expression level. In conclusion, the Ha-c-Myc was expressed through a prokaryotic expression system, and the polyclonal anti-Ha-c-Myc antibody was obtained. Ha-c-Myc may promote the expression of HaSCP-2 and play an important role in the lipid metabolism of H. armigera. These results may facilitate further study on the potential role and function mechanism of Ha-c-Myc in H. armigera and provide experimental data for exploring new targets of green pesticides.
Animals ; Rabbits ; Escherichia coli/metabolism* ; Enzyme-Linked Immunosorbent Assay ; Moths/genetics* ; Blotting, Western ; Larva/genetics* ; Isoantibodies/metabolism* ; Antibody Specificity

Transmembrane emp24 domain (TMED) gene is closely related to immune response, signal transduction, growth and disease development in mammals. However, only the Drosophila TMED gene has been reported on insects. We identified the TMED family genes of silkworm, Tribolium castaneum, tobacco moth and Italian bee from their genomes, and found that the TMED family gene composition patterns of one α-class, one β-class, one δ-class and several γ-classes arose in the common ancestor of pre-divergent Hymenoptera insects, while the composition of Drosophila TMED family members has evolved in a unique pattern. Insect TMED family γ-class genes have evolved rapidly, diverging into three separate subclasses, TMED6-like, TMED5-like and TMED3-like. The TMED5-like gene was lost in Hymenoptera, duplicated in the ancestors of Lepidoptera and duplicated in Drosophila. Insect TMED protein not only has typical structural characteristics of TMED, but also has obvious signal peptide. There are seven TMED genes in silkworm, distributed in six chromosomes. One of seven is single exon and others are multi-exons. The complete open reading frame (ORF) sequences of seven TMED genes of silkworm were cloned from larval tissues and registered in GenBank database. BmTMED1, BmTMED2 and BmTMED6 were expressed in all stages and tissues of the silkworm, and all genes were expressed in the 4th and 5th instar and silk gland of the silkworm. The present study revealed the composition pattern of TMED family members, their γ class differentiation and their evolutionary history, providing a basis for further studies on TMED genes in silkworm and other insects.
Animals ; Bombyx/metabolism* ; Genes, Insect/genetics* ; Moths/metabolism* ; Insecta/metabolism* ; Drosophila ; Insect Proteins/metabolism* ; Phylogeny ; Mammals/genetics*

Protein-protein interactions between viruses and hosts are common during viral infection and replication. In this study, a cDNA library from larvae of Plutella xylostella was constructed and used for screening of genes encoding proteins interacting with Plutella xylostella granulovirus (PlxyGV) proteins. Two cDNA clones containing genes encoding proteins interacting with PlxyGV PP31 were identified by yeast two-hybrid assays. Sequence analysis showed that the genes encoded homologues of receptor for activated protein C kinase (RACK) and methionine aminopeptidase 2 (MetAP2), respectively. The P. xylostella rack gene and the PlxyGV pp31 was expressed in an E. coli strain to produce proteins fused with a 6-His or a GST tag. It was shown that the rack was expressed as a 38kD peptide as prospected. The 38kD His-tagged peptide was co-purified with GST-PP31 by GST-bind resin in GST-pulldown assays, confirming interaction between the PlxyGV PP31 and the RACK protein of P. xylostella.
Aminopeptidases ; genetics ; physiology ; Animals ; Gene Library ; Granulovirus ; physiology ; Metalloendopeptidases ; genetics ; physiology ; Moths ; virology ; Receptors for Activated C Kinase ; Receptors, Cell Surface ; genetics ; physiology

Plutella xylostella granulovirus (PlxyGV) contains homologs of 15 Autographa californica MNPV (AcMNPV) late expression factor (lef) genes. The prospective products of 14 PlxyGV lef genes (ie-0 is not included) share 13%-53% amino acid similarity with their corresponding homologs of AcMNPV, among which LEF-9, LEF-8 and P47, three subunits of the virus-encoded RNA polymerase, share 49%, 53% and 46% sequence identity, respectively. In this study, an established transient expression system was used to test the ability of the PlxyGV LEFs to activate an AcMNPV vp39 promoter-driven reporter gene in SF9 cells. It was shown that PlxyGV le f-2 replaced the corresponding AcMNPV gene and exhibited partial activity in the context of the remaining set of AcMNPV le fs. PlxyGV LEF-2 was found to contain additional 100aa and 70aa at the C-terminus in comparison with the LEF-2 of other GVs and lepidopteran NPVs respectively.
Amino Acid Sequence ; Animals ; Gene Expression Regulation, Viral ; Granulovirus ; chemistry ; genetics ; metabolism ; Molecular Sequence Data ; Moths ; virology ; Nucleopolyhedrovirus ; genetics ; metabolism ; Sequence Alignment ; Viral Proteins ; genetics ; metabolism

The Cry1Ab differs most significantly from the other related ICPs by its absence of a carboxyl terminus of 28 amino acids including four cysteines; consequently it is less stable. We report that the helper protein P20 plays a role in the expression and crystallization of Cry1Ab. Three Cry1Ab expression plasmids pT1B, pP1B, and pDP1B, were constructed based on the shuttle vector pHT3101. The vector pT1B does not contain the p20 gene, pP1B carries p20, and pDP1B contains p20 with cry1A(c) promoter. Transformants were obtained by electroporating the plasmids into Bacillus thuringiensis acrystalliferous mutant CryB. Western blot demonstrated that crylAb was expressed as a 130 kD protein in all the transformants, and some of the protein was partially degraded into a 60 kD peptide. Quantitative protein analysis indicated that the amount of the 130 kD protein varied in the transformants and was in the ratio of 1:1.4:1.5 for PT1B, pP1B and pDP1B respectively. For the 60 kD proteins, the ratio was 1:1.1:1.6. Microscopic examination revealed that the size of the typical pyramidal crystals in the three transformants was in the order of T1B < P1B < DP1B. Bioassay showed that T1B, P1B and DP1B were all toxic to the larvae of Helicoverpa armigera with similar LC50. This study suggested that P20 plays a role in the expression and crystallization of Cry1Ab.
Animals ; Bacillus thuringiensis ; genetics ; metabolism ; ultrastructure ; Bacterial Proteins ; genetics ; metabolism ; pharmacology ; Biological Assay ; methods ; Blotting, Western ; Electroporation ; Endotoxins ; genetics ; metabolism ; pharmacology ; Hemolysin Proteins ; genetics ; metabolism ; pharmacology ; Microscopy, Electron, Transmission ; Moths ; drug effects ; Promoter Regions, Genetic ; genetics

A binary plant expression vector, pCM12-slm, carrying the aroAM12 mutant gene encoding bacterial 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) and the Bts1m recombinant gene consisting of 331 N-terminal amino acids of CryIAc and 284 C-terminal amino acids of CryIAb has been constructed. The truncated Bts1 gene was fused with the PR1b signal peptide sequence and expressed in tobacco plants under the control of 2E-CaMV35S promoter and the omega (omega) translation enhancer sequence from tobacco mosaic virus. The mutant aroAM12 was fused with the transit sequence of tobacco EPSPS and expressed in tobacco plants under the control of the CaMV35S promoter. Tobacco leaves were transformed with Agrobacterium tumefaciens LBA4404 harboring the pCM12-slm plasmid, and the transgenic plants were selected directly on medium containing the herbicide. Forty glyphosate resistant plants were regenerated, with a transformation frequency of 27%. Transgenic plants were initially assessed for glyphosate resistance by placing leaf discs on shoot induction media containing the herbicide. Rooted plantlets, propagated from selected transgenic tobacco, were transferred to soil in a greenhouse and tested for glyphosate resistance by spraying them with Roundup at a commercial recommended dose. The glyphosate resistance assay indicated that all the transgenic plants showed highly resistant to the herbicide. The PCR assay showed that the aroAM12 gene was present in all of the 40 T0 transfer plants, and Bts1m genes present in 28 of 40 of the transgenic plants. Southern blot analysis further confirmed that the copy number of the transgenes varied from one to three copies in different transgenic plants. Northern blot and immunodot blot showed that the aroAM12 and Bts1m genes were expressed at the transcription and translation levels. Transgenic plants containing both the aroA M12 and Bts1m genes were further assessed for insect resistance. Tobacco leaves of T0 transgenic plants were infested with tobacco bollworm H. assulta larvae for 6 days. The result (table 1) showed that the survival rate of insect larvae was between 0-10%, and the growth of insect larvae was seriously inhibited, suggesting pCM12-slm as a dual functional vector with potential application in breeding of glyphosate and insect resistance transgenic plants.
Agrobacterium tumefaciens ; genetics ; Animals ; Blotting, Northern ; Blotting, Southern ; Genetic Vectors ; genetics ; physiology ; Herbicides ; pharmacology ; Moths ; pathogenicity ; Plant Diseases ; parasitology ; Plant Leaves ; drug effects ; genetics ; parasitology ; Plants, Genetically Modified ; drug effects ; genetics ; parasitology ; Polymerase Chain Reaction ; Tobacco ; drug effects ; genetics ; parasitology

To indicate the relationship between structure and function of loops from Bacillus thuringiensis insecticidal crystal protein Cry1Ba, and the influence of amino acids mutation on toxicity against diamond back moth Plutella xylostella, five mutations at the loops of Cry1Ba were constructed by overlapping primer PCR, and expressed in E. coli BL21 (DE3). Bioassay results showed that the toxicity of mutation M1 (loop1: 340WSNTR344-deletion), compared with that of Cry1Ba (LC50 0.96 microg/mL), decreased significantly with LC50 35.51 microg/mL. And the toxicity of mutation M2 (402Y-G), M3 (400GIYLEP405-PSAV), M4 (400GIYLEPIH407-ILGS) was also reduced to some extent respectively. Only M5 (mutation at loop3: 472LQSRV476 - AGAVYTL) showed slightly increased activity against P. xylostella, but not significantly (LC50 0.81 microg/mL). Referring to the structures of Cry1Ba which was predicted using Swiss-Model software, and bioassay data, we can conclude that loop1 and loop2 play a important role on determining the activity of Cry1Ba against P. xylostella.
Animals ; Bacillus thuringiensis ; genetics ; metabolism ; Bacterial Proteins ; chemistry ; genetics ; Endotoxins ; chemistry ; genetics ; Escherichia coli ; genetics ; metabolism ; Hemolysin Proteins ; chemistry ; genetics ; Models, Molecular ; Moths ; microbiology ; Mutation ; Protein Structure, Secondary ; Structure-Activity Relationship

The knowledge of the relationship between sequence characteristics of insecticidal crystal proteins (ICP) and their inhibitory against Plutella xylostella provided helpful information for the rational design of ICP with desirable activity against Plutella xylostella. The four key loops of ICP with determined activities against Plutella xylostella were selected to study the quantitative relationship between sequence characteristics and insecticidal activity. The first principle components' score vectors for 20 amino acids were assigned to converting amino acids into data. The six key sites X3, X9, X12, X13, X14 and X19 were predicted by stepwise regression method. The amino acids L/ X3, S/ X9, S/ X12, T/ X13, A/ X14 and G/ X19 found by partial least squares regression and second order polynomial models were predicted to increase the activity of ICP against Plutella xylostella.
Amino Acid Sequence ; Animals ; Bacterial Proteins ; genetics ; pharmacology ; Endotoxins ; genetics ; pharmacology ; Hemolysin Proteins ; genetics ; pharmacology ; Insecticides ; metabolism ; pharmacology ; Models, Biological ; Molecular Sequence Data ; Moths ; genetics ; metabolism ; Pest Control, Biological ; Sequence Analysis, Protein

AIMTo investigate the expression of recombinant human phosphodiesterase 3A (HPDE3A) using baculovirus expression system in Tn cell line.

METHODSThe HPDE3A cDNA was recombined with baculovirus, and then the recombinant was transfected into Tn cell line. The expression of HPDE3A in Tn cell line was detected and identified by the RT-PCR, SDS-PAGE and Western blotting.

RESULTSThe recombinant HPDE3A protein was stably expressed in Tn cell line and detected by the distinct morphological changes of Tn cell, RT-PCR, SDS-PAGE and Western blotting using polyclonal antibody. The M(w) of the recombinant protein was about 120 kD.

CONCLUSIONRecombinant HPDE3A can be expressed in Tn cell line using the baculovirus expression system, and thus provided the basic material for studying its bioactivity and application in screening for HPDE3A inhibitor.

3',5'-Cyclic-AMP Phosphodiesterases ; genetics ; metabolism ; Animals ; Baculoviridae ; genetics ; Cell Line ; Cyclic Nucleotide Phosphodiesterases, Type 3 ; Electrophoresis, Polyacrylamide Gel ; Moths ; cytology ; enzymology ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Recombinant Proteins ; genetics ; metabolism ; Transfection

The CrylA Crystal Protein from Bacillus thuringiensis is associated with DNA, but the role and sequences of these DNA molecules are unknown. CrylA bipyramidal crystals from B. thuringiensis strain 4.0718 was selectively dissolved and associated DNA was extracted from protoxin. The DNA was digested with Nde I to obtain 3 to 5 kb fragments and then the fragments were subcloned into pMD18-T vector, screening of recombinants were done by PCR-RFLP and sequencing. The ORF of cry1Ac gene was amplified by primers designed and then subcloned. The 3.5 kb BamH I and Sal I fragments of pMDX35 was inserted into the pET30a vector, giving 8.9 kb recombinant plasmid, pETX35. ETX35 strain were obtained by transformed pETX35 into B121 (DE3). A 141 kD fusion protein was superexpressed as inclusion bodies. Quantitative protein analysis indicated that the amount of 141 kD protein was above the level of 51.36% of total cellular protein. Plasmid pHTX42 constructed from shuttle vector pHT304 was transformed B. thuringiensis acrystalliferous strain XBU001 with electroporation to obtain the recombinant HTX42. The recombinant protein was found with a molecular mass of 130 kD on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Scanning analysis indicated that the expressed protein accounted up to 79.28% of total cellular proteins and accumulated in the cells mounted up to 64.13% of cellular dry weight. Under Atomic Force Microscopy (AFM), typical bipyramidal crystals from HTX42 strain were found with a size of 1.2 microm x 2.0 microm. Bioassay showed that these inclusion bodies of ETX35 strain and crystals from HTX42 strain were highly toxic against the larvae of Plutella xylostella. On such a base, constructing insecticidal recombinant and analyzing the source, structure, and function of the 20 kb DNA can be further achieved.
Animals ; Bacillus thuringiensis ; genetics ; Bacterial Proteins ; biosynthesis ; genetics ; pharmacology ; Cloning, Molecular ; Endotoxins ; biosynthesis ; genetics ; pharmacology ; Hemolysin Proteins ; biosynthesis ; genetics ; pharmacology ; Microscopy, Atomic Force ; Moths ; Plasmids ; Recombinant Proteins ; biosynthesis ; pharmacology