• Title/Summary/Keyword: Signal Peptide

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Cloning, Characterization and Expression Analysis of Interleukin-10 from the Zebrafish (Danio rerion)

  • Zhang, Dian-Chang;Shao, Yan-Qing;Huang, Yan-Qin;Jiang, Shi-Gui
    • BMB Reports
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    • v.38 no.5
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    • pp.571-576
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    • 2005
  • Cytokines are proteins produced by many different cells of the immune system and play a significant role in initiating and regulating the inflammatory process. In this research, an important cytokine, interleukin-10 (IL-10) gene, has been identified and characterized from zebrafish (Danio rerio) genome database. Zebrafish IL-10 is located within a 2690 bp fragment and contains five exons and four introns, sharing the same organization with mammalian IL-10 genes. An open reading frame of 543 bp was found to encode a putative 180 amino acid protein with a signal peptide of 22 amino acids, which shares 29.7-80.9% homology with amino acid sequences of other known IL-10. The signature motif of IL-10 is also conserved in zebrafish IL-10. The predicted transcript was finally confirmed by sequencing of cDNA clones. Multi-tissue reverse transcriptase PCR (RT-PCR) was performed to examine the tissue distribution and expression regulation of this gene in seven organs of normal and lipopolysaccharide (LPS) stimulation zebrafish. The results demonstrated that this gene was expressed slightly in normal kidney, gill and gut, no expression was detected in other four tissues. The expression was clearly upregulated after LPS stimulation. Using the ideal zebrafish model, further study of IL-10 characterization and function may provide insight on the understanding of the innate immune system.

The EST Analysis and Transgene Expression System in Rice

  • Kim, Jukon;Nahm, Baek-Hie
    • Journal of Plant Biotechnology
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    • v.1 no.1
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    • pp.46-55
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    • 1999
  • The expressed sequence tags(ESTs) from immature seed of rice, Oryza sativa cv Milyang 23, were partially sequenced and analyzed by homology. As of 1998, the partial sequences of about 6,600 cDNA clones were analyzed from normal and normalized immature seed cDNA libraries. About 2,200 ESTs were putatively identified by BLASTX deduced amino acid sequence homology analysis. About 20% of them were putatively identified as storage proteins. Also the clones were highly homologous to genes involved particularly in starch biosynthesis, glycolysis, signal transduction and defenses. Compared to 35% of redundancy in the ESTs of normal cDNA library, that from the substracted library was 15%. The Korea Rice Genome Network is maintained to provide the updated information of sequences, their homologies and sequence alignments of ESTs. For the stable expression of transgene in rice, diverse vectors were developed for overexpression, targeting and gene dosage effect with transit peptides (Tp) and matrix attachment region (MAR) sequence from chicken lysozyme locus. The rice calli were transformed via Agrobacterium tumefaciens LBA4404(pSB1) with the triparental mating technique and selected by herbicide resistance. The green fluorescent protein(GFP) gene in expression vector under the control of rbcS promoter-Tp was overexpressed upto 10 % of the total soluble protein. In addition, the Tp-sGFP fusion protein was properly processed during translocation into chloroplast. The expression of sGFP in the presence of MAR sequences was analyzed with Northern and immunoblot analysis. All the lines in which sGFP transgene with MAR sequence, showed position independent and copy number-dependent expression, while the lines without MAR showed the varied level of expression with the integration site. Thus the MAR sequence significantly reduced the variation in transgene expression between independent transformants.

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Molecular Cloning and Characterization of a New C-type Lysozyme Gene from Yak Mammary Tissue

  • Jiang, Ming Feng;Hu, Ming Jun;Ren, Hong Hui;Wang, Li
    • Asian-Australasian Journal of Animal Sciences
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    • v.28 no.12
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    • pp.1774-1783
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    • 2015
  • Milk lysozyme is the ubiquitous enzyme in milk of mammals. In this study, the cDNA sequence of a new chicken-type (c-type) milk lysozyme gene (YML), was cloned from yak mammary gland tissue. A 444 bp open reading frames, which encodes 148 amino acids (16.54 kDa) with a signal peptide of 18 amino acids, was sequenced. Further analysis indicated that the nucleic acid and amino acid sequences identities between yak and cow milk lysozyme were 89.04% and 80.41%, respectively. Recombinant yak milk lysozyme (rYML) was produced by Escherichia coli BL21 and Pichia pastoris X33. The highest lysozyme activity was detected for heterologous protein rYML5 (M = 1,864.24 U/mg, SD = 25.75) which was expressed in P. pastoris with expression vector $pPICZ{\alpha}A$ and it clearly inhibited growth of Staphylococcus aureus. Result of the YML gene expression using quantitative polymerase chain reaction showed that the YML gene was up-regulated to maximum at 30 day postpartum, that is, comparatively high YML can be found in initial milk production. The phylogenetic tree indicated that the amino acid sequence was similar to cow kidney lysozyme, which implied that the YML may have diverged from a different ancestor gene such as cow mammary glands. In our study, we suggest that YML be a new c-type lysozyme expressed in yak mammary glands that plays a role as host immunity.

Differential Protein Expression in EC304 Gastric Cancer Cells Induced by Alphastatin

  • Wang, Xin-Xin;Sun, Rong-Ju;Wu, Meng;Li, Tao;Zhang, Yong;Chen, Lin
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.4
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    • pp.1667-1674
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    • 2012
  • Objective: To explore the differential protein expression profile in EC304 gastric cancer cells induced by alphastatin. Methods: Cultured EC304 cells in the exponential phase of growth were randomly divided into alphastatin and control groups. Total proteins were extracted and the two dimensional electrophoresis (2-DE) technique was applied to analyze differences in expression with ImageMaster 2D Platinum 5.0 software. Proteins were identified using the MASCOT database and selected differently expressed proteins were characterised by western blotting and immunofluorescence. Results: $1350{\pm}90$ protein spots were detected by the ImageMaster software in the 2-DE gel images from the control and alphastatin groups. The match rate was about 72-80% for the spectrum profiles, with 29 significantly different protein spots being identified, 10 upregulated, 16 downregulated, two new and one lost. The MASCOT search scores were 64-666 and the peptide matching numbers were 3-27 with sequence coverage of 8-62%. Twenty-three proteins were checked by mass spectrometry, including decrease in Nm23 and profilin-2 isoform b associated with the regulation of actin multimerisation induced by extracellular signals. Conclusion: The proteome in EC304 cells is dramatically altered by alphastatin, which appears to play an important role in modulating cellular activity and anti-angiogenesis by regulating protein expression and signal transduction pathways through Nm23 and profilin-2 isoform b, providing new research directions for anti-angiogenic therapy of gastric cancer.

Purification and Characterization of a Major Extracellular Chitinase from a Biocontrol Bacterium, Paenibacillus elgii HOA73

  • Kim, Yong Hwan;Park, Seur Kee;Hur, Jin Young;Kim, Young Cheol
    • The Plant Pathology Journal
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    • v.33 no.3
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    • pp.318-328
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    • 2017
  • Chitinase-producing Paenibacillus elgii strain HOA73 has been used to control plant diseases. However, the antimicrobial activity of its extracellular chitinase has not been fully elucidated. The major extracellular chitinase gene (PeChi68) from strain HOA73 was cloned and expressed in Escherichia coli in this study. This gene had an open reading frame of 2,028 bp, encoding a protein of 675 amino acid residues containing a secretion signal peptide, a chitin-binding domain, two fibronectin type III domains, and a catalytic hydrolase domain. The chitinase (PeChi68) purified from recombinant E. coli exhibited a molecular mass of approximately 68 kDa on SDS-PAGE. Biochemical analysis indicated that optimum temperature for the actitvity of purified chitinase was $50^{\circ}C$. However, it was inactivated with time when it was incubated at $40^{\circ}C$ and $50^{\circ}C$. Its optimum activity was found at pH 7, although its activity was stable when incubated between pH 3 and pH 11. Heavy metals inhibited this chitinase. This purified chitinase completely inhibited spore germination of two Cladosporium isolates and partially inhibited germination of Botrytis cinerea spores. However, it had no effect on the spores of a Colletotricum isolate. These results indicate that the extracellular chitinase produced by P. elgii HOA73 might have function in limiting spore germination of certain fungal pathogens.

Genomic Sequence Analysis and Organization of BmKαTx11 and BmKαTx15 from Buthus martensii Karsch: Molecular Evolution of α-toxin genes

  • Xu, Xiuling;Cao, Zhijian;Sheng, Jiqun;Wu, Wenlan;Luo, Feng;Sha, Yonggang;Mao, Xin;Liu, Hui;Jiang, Dahe;Li, Wenxin
    • BMB Reports
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    • v.38 no.4
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    • pp.386-390
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    • 2005
  • Based on the reported cDNA sequences of $BmK{\alpha}Txs$, the genes encoding toxin $BmK{\alpha}Tx11$ and $BmK{\alpha}Tx15$ were amplified by PCR from the Chinese scorpion Buthus martensii Karsch genomic DNA employing synthetic oligonucleotides. Sequences analysis of nucleotide showed that an intron about 500 bp length interrupts signal peptide coding regions of $BmK{\alpha}Tx11$ and $BmK{\alpha}Tx15$. Using cDNA sequence of $BmK{\alpha}Tx11$ as probe, southern hybridization of BmK genome total DNA was performed. The result indicates that $BmK{\alpha}Tx11$ is multicopy genes or belongs to multiple gene family with high homology genes. The similarity of $BmK{\alpha}$-toxin gene sequences and southern hybridization revealed the evolution trace of $BmK{\alpha}$-toxins: $BmK{\alpha}$-toxin genes evolve from a common progenitor, and the genes diversity is associated with a process of locus duplication and gene divergence.

Expression and Characterization of CMCax Having β-1,4-Endoglucanase Activity from Acetobacter xylinum

  • Koo, Hyun-Min;Song, Sung-Hee;Pyun, Yu-Ryang;Kim, Yu-Sam
    • BMB Reports
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    • v.31 no.1
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    • pp.53-57
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    • 1998
  • The CMCax gene from Acetobacter xylinum ATCC 23769 was cloned and expressed in E. coli. With this gene, three gene products - mature CMCax, CMCax containing signal peptide(pre-CMCax), and a glutathione-S-transferase(GST)-CMCax fusion enzyme - were expressed. CMCax and pre-CMCax are aggregated to multimeric forms which showed high CMC hydrolysis activity, whereas GST-CMCax was less aggregated and showed lower activity, indicating that oligomerization of CMCax controbutes to the cellulose hydrolysis activity to achieve greater efficiency. The enzyme was identified to be an $\beta$-1,4-endoglucanase, which catalyzes the cleavage of internal $\beta$-1,4-glycosidic bonds of cellulose. The reaction products, cellobiose and cellotriose, from cellopentaose as a substrate, were identified by HPLC. Substrate specificity of cellotetraose by this enzyme was poor, and the reaction products consisted of glucose, cellobiose, and cellotriose in a very low yield. Theses results suggested that cellopentaose might be the oligosaccharide substrate consisting of the lowest number of glucose. The optimum pH of CMCax and pre CMCax was about 4.5, whereas that of GST-CMCas was rather broad at pH 4.5-8. The physiological significance of cellulose-hydrolyzing enzyme, CMCax, having such low $\beta$-1,4-endoglucanase activity and low optimum pH in cellulose-producing A. xylinum is not clearly known yet, but it seems to be closely related to the production of cellulose.

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Characterization of the ${\beta}-Cyclodextrin$ Glucanotransferase Bacillus firmus var. alkalophilus and Its Expression in E. coli

  • Park, Tae-Hyung;Shin, Hyun-Dong;Lee, Yong-Hyun
    • Journal of Microbiology and Biotechnology
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    • v.9 no.6
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    • pp.811-819
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    • 1999
  • The ${\beta}-CGTase$ gene of alkalophilic Bacillus firmus var. alkalophilus was cloned into E. coli using $pZErO^{TM}-2$ as a vector. The cloned gene encoded a total of 710 amino acid residues consisting of 674 amino acids of the matured protein and 36 amino acids of the signal peptide, including 20 amino acids from the lacZ gene in the vector. Although the cloned ${\beta}-CGTase$ gene did not contain the promoter and start codons, it was expressed by the lac promoter and lacZ start codon in the $pZErO^{TM}$ vector. A comparison was made with the amino acid sequence and ten other CGTases from Bacillus sp. Also, ten highly conserved regions, which are important amino acid residues in catalysis of CGTase, were identified. The lac promoter used for expression of the ${\beta}-CGTase$ gene was induced constitutively in recombinant E. coli even without IPTG possibly because of a lack of the lacI gene in both host and vector, repressing the lacZ gene in the lac operon. Its expression was catabolically repressed by glucose, however, its repression was reduced by soluble starch, mainly because of the extremely high increase of the cAMP level. ${\beta}-CGTase$ can be overproduced in the recombinant E. coli by maintaining intracellular cAMP levels mostly through the intermittent feeding of glucose during cultivation.

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Bacillus cereus ASK-202에서 cloning 된 agarase의 물리 ${\cdot}$ 화학적 특성

  • Hwang, Seon-Hui;Ha, Sun-Deuk;Kim, Bong-Jo;Gong, Jae-Yeol
    • 한국생물공학회:학술대회논문집
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    • 2002.04a
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    • pp.534-537
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    • 2002
  • An agarase gene from Bacillus cereus ASK202 was expressed in high levels by E. coli BL21(DE3)/pEBA1 using pET28a(+) vector system with the inducible T7 promoter in the presence of isopropyl- ${\beta}$ -thiogalactopyranoside. The open reading frame encodes 761 amino acid residues with a calculated molecular weight of 83,300 daltons and a potential signal peptide about 36 amino acid residues at the N-terminus. E. coli BL21(DE3)/pEBA1 produce 1280 unit/ ${\ell}$ of agarase. The optimum physical condition for the agarase activity was pH 5.6, and $40^{\circ}C$, respectively. The agarase activity was stable up pH $4.0{\sim}9.0$ and $4{\sim}40^{\circ}C$. The km and maximum rate of metabolism for agar were 0.068mg/$m{\ell}$ and 0.094mg/$m{\ell}{\cdot}min$, respectively.

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High-yield Production of Functional Human Lactoferrin in Transgenic Cell Cultures of Siberian Ginseng(Acanthopanax senticosus)

  • Jo, Seung-Hyun;Kwon, Suk-Yoon;Park, Doo-Sang;Yang, Kyoung-Sil;Kim, Jae-Whune;Lee, Ki-Teak;Kwak, Sang-Soo;Lee, Haeng-Soon
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.11 no.5
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    • pp.442-448
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    • 2006
  • Human lactoferrin (hLf) is an iron-binding glycoprotein that has been considered to play many biological roles in the human, including the stimulation of the immune system, antimicrobial and anti-inflammatory effects, and regulation of iron absorption. We generated transgenic Siberian ginseng (Acanthopanax senticosus) cell cultures producing a functional hLf protein using the signal peptide sequence from the endoplasmic reticulum and driven by an oxidative stress-inducible SWPA2 promoter which is highly expressed in plant cell cultures. The production of hLf increased proportionally to cell growth and showed a maximal level (up to 3.6% of total soluble protein) at the stationary phase in suspension cultures. Full-length hLf protein was identified by immunoblot analysis in transgenic cell cultures of Siberian ginseng. Recombinant hLf (rhLf) was purified from suspension cells of Siberian ginseng by ammonium sulfate precipitation, cation-exchange and gel filtration chromatography. N-terminal sequences of rhLf were identical to native hLf (nhLf). The overall monosaccharide composition of rhLf showed the presence of plant specific xylose while sialic acid is absent. Antibacterial activity of purified rhLf was higher than that of nhLf. Taken together, we anticipate that medicinal Siberian ginseng cultured cells, as demonstrated by this study, will be a biotechnologically useful source for commercial production of functional hLf not requiring further purification.