• Title/Summary/Keyword: Signal Peptide

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Transcriptional regulation of chicken leukocyte cell-derived chemotaxin 2 in response to toll-like receptor 3 stimulation

  • Lee, Seokhyun;Lee, Ra Ham;Kim, Sung-Jo;Lee, Hak-Kyo;Na, Chong-Sam;Song, Ki-Duk
    • Asian-Australasian Journal of Animal Sciences
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    • v.32 no.12
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    • pp.1942-1949
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    • 2019
  • Objective: Leukocyte cell-derived chemotaxin 2 (LECT2) is associated with several physiological processes including inflammation, tumorigenesis, and natural killer T cell generation. Chicken LECT2 (chLECT2) gene was originally identified as one of the differentially expressed genes in chicken kidney tissue, where the chickens were fed with different calcium doses. In this study, the molecular characteristics and gene expression of chLECT2 were analyzed under the stimulation of toll-like receptor 3 (TLR3) ligand to understand the involvement of chLECT2 expression in chicken metabolic disorders. Methods: Amino acid sequence of LECT2 proteins from various species including fowl, fish, and mammal were retrieved from the Ensembl database and subjected to Insilco analyses. In addition, the time- and dose-dependent expression of chLECT2 was examined in DF-1 cells which were stimulated with polyinosinic:polycytidylic acid (poly [I:C]), a TLR3 ligand. Further, to explore the transcription factors required for the transcription of chLECT2, DF-1 cells were treated with poly (I:C) in the presence or absence of the nuclear factor ${\kappa}B$ ($NF{\kappa}B$) and activated protein 1 (AP-1) inhibitors. Results: The amino acid sequence prediction of chLECT2 protein revealed that along with duck LECT2 (duLECT2), it has unique signal peptide different from other vertebrate orthologs, and only chLECT2 and duLECT2 have an additional 157 and 161 amino acids on their carboxyl terminus, respectively. Phylogenetic analysis suggested that chLECT2 is evolved from a common ancestor along with the actinopterygii hence, more closely related than to the mammals. Our quantitative polymerase chain reaction results showed that, the expression of chLECT2 was up-regulated significantly in DF-1 cells under the stimulation of poly (I:C) (p<0.05). However, in the presence of $NF{\kappa}B$ or AP-1 inhibitors, the expression of chLECT2 is suppressed suggesting that both $NF{\kappa}B$ and AP-1 transcription factors are required for the induction of chLECT2 expression. Conclusion: The present results suggest that chLECT2 gene might be a target gene of TLR3 signaling. For the future, the expression pattern or molecular mechanism of chLECT2 under stimulation of other innate immune receptors shall be studied. The protein function of chLECT2 will be more clearly understood if further investigation about the mechanism of LECT2 in TLR pathways is conducted.

Heterologous Expression of Interferon α-2b in Lactococcus lactis and its Biological Activity against Colorectal Cancer Cells

  • Meilina, Lita;Budiarti, Sri;Mustopa, Apon Zaenal;Darusman, Huda Shalahudin;Triratna, Lita;Nugraha, Muhammad Ajietuta;Bilhaq, Muhammad Sabiq;Ningrum, Ratih Asmana
    • Microbiology and Biotechnology Letters
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    • v.49 no.1
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    • pp.75-87
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    • 2021
  • Type I Interferons (IFNα) are known for their role as biological anticancer agents owing to their cell-apoptosis inducing properties. Development of an appropriate, cost-effective host expression system is crucial for meeting the increasing demand for proteins. Therefore, this study aims to develop codon-optimized IFNα-2b in L. lactis NZ3900. These cells express extracellular protein using the NICE system and Usp45 signal peptide. To validate the mature form of the expressed protein, the recombinant IFNα-2b was screened in a human colorectal cancer cell line using the cytotoxicity assay. The IFNα-2b was successfully cloned into the pNZ8148 vector, thereby generating recombinant L. lactis pNZ8148-SPUsp45-IFNα-2b. The computational analysis of codon-optimized IFNα-2b revealed no mutation and amino acid changes; additionally, the codon-optimized IFNα-2b showed 100% similarity with native human IFNα-2b, in the BLAST analysis. The partial size exclusion chromatography (SEC) of extracellular protein yielded a 19 kDa protein, which was further confirmed by its positive binding to anti-IFNα-2b in the western blot analysis. The crude protein and SEC-purified partial fraction showed IC50 values of 33.22 ㎍/ml and 127.2 ㎍/ml, respectively, which indicated better activity than the metabolites of L. lactis NZ3900 (231.8 ㎍/ml). These values were also comparable with those of the regular anticancer drug tamoxifen (105.5 ㎍/ml). These results demonstrated L. lactis as a promising host system that functions by utilizing the pNZ8148 NICE system. Meanwhile, codon-optimized usage of the inserted gene increased the optimal protein expression levels, which could be beneficial for its large-scale production. Taken together, the recombinant L. lactis IFNα-2b is a potential alternative treatment for colorectal cancer. Furthermore, its activity was analyzed in the WiDr cell line, to assess its colorectal anticancer activities in vivo.

Antibody Functionalized UiO-66-(COOH)2 Amplified Surface Plasmon Resonance Analysis Method for fM Oxytocin (펨토몰 농도의 옥시토신 검출을 위한 항체 기능성 UiO-66-(COOH)2 증폭형 표면 플라즈몬 공명 분석법 개발)

  • Myungseob Lee;Ha-Young Nam;Su Yeon Park;Sung Hwa Jhung;Hye Jin Lee
    • Applied Chemistry for Engineering
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    • v.35 no.4
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    • pp.335-340
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    • 2024
  • In this paper, we synthesized organic and inorganic hybrid materials to introduce antibody functionality to UIO-66 and incorporated them into a surface plasmon resonance (SPR) assay to enhance the sensitivity of detecting small molecules such as oxytocin. A biological marker peptide called oxytocin may help in the diagnosis of heart failure, Alzheimer's disease, and cancer. To detect oxytocin at concentrations as low as a few femtomole (fM), we developed a surface sandwich assay utilizing a pair of oxytocin-specific antibodies for enhancing selectivity and one of metal organic frameworks [e.g., UiO-66-(COOH)2] possessing high porosity and surface-area as a signal amplifier. Initially, real-time SPR assays were used to confirm that each selected oxytocin-specific antibody binds strongly to oxytocin and to different binding sites on oxytocin. One of these antibodies (e.g., anti-OXT[OTI5G4]) was immobilized on the surface of a thin gold chip. Upon sequential injecting of oxytocin and the other antibody (e.g., anti-OXT[4G11]) conjugated to UiO-66-(COOH)2 onto the surface to form the surface sandwich complex of anti-OXT[OTI5G4]/oxytocin/UiO-66-(COOH)2-anti-OXT[4G11]), SPR changes, which varied with oxytocin concentration, were then measured in real time. The results demonstrated that sensitivity was amplified by over a million-fold compared to assays without UiO-66-(COOH)2, enabling oxytocin detection down to approximately 10 fM.

Disturbance of $\alpha$-Amylase Secretion from Bacillus amyloliquefaciens Cells by the Treatment of Puromycin and Magnesium (Bacillus amyloliquefaciens에서 Puromycin 과 Magnesium에 의한 $\alpha$-Amylase 의 분비저해)

  • 안순자;김순옥;이동희;송방호
    • Microbiology and Biotechnology Letters
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    • v.17 no.5
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    • pp.412-420
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    • 1989
  • To know how the ribosomes involved in secretory protein synthesis were attached to the cytoplasmic membrane in Bacillus amyloliquefaciens, the cells were treated with puromycin combinated with magnesium at the logarithmic phase, and the variation of cell-bound and extracellular $\alpha$-amylase activity was assayed for determining the $\alpha$-amylase translocation blocking through the cytoplasmic membrane. In the abnormal $\alpha$-amylase producing mutant in which the C-terminal of the $\alpha$-amylase structure was deleted, B. umytotiquefaciens CH10-2, the $\alpha$-amylase was translocated normally through the cytoplasmic membranes, and the translocation blocking by puromycin was revealed to have a similar pattern as that in the wild type. This means that the C-terminal part of the enzyme structure may not have a signal for secretion. The cell death of the logarithmic phase cells in both strains was not affected much under 20$\mu\textrm{g}$/$m\ell$ of puromycin, however, the $\alpha$-amylase translocation was blocked markedly under less than 10$\mu\textrm{g}$/$m\ell$ of the puromycin concentration. The blocking of the enzyme secretion by puromycin may be due to the detachment of the ribosomes from cytoplasmic membranes by disturbing the nascent polypeptide synthesis. Further evidence for confirming this was that the detachment was increased in 50 mM of magnesium ion because the extracellular $\alpha$-amylase activity was decreased more under this condition. If the cells were treated with trypsin combinated with Iysozyme, the extracellular $\alpha$-amylase activity from the cultured medium was reduced markedly, however, the activity from the cells treated with trypsin only was not reduced. This means that the nascent polypeptides protruding from the cytoplasmic membrane were sensitive to the trypsin digestion, whereas the matured ones were not. Therefore, the protruding polypeptides from the cytoplasmic membranes may be truncated by trypsin before forming their final tertiary structures by folding in the cell wall layer.

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Inhibitory Effect of Protaetiamycine 9 Derived from Protaetia brevitarsis seulensis Larvae on LPS-mediated Inflammation in RAW264.7 Cells (LPS로 자극한 RAW264.7 대식세포에서 흰점박이꽃무지 유충 유래 Protaetiamycine 9의 항염증 효과)

  • Choi, Ra-Yeong;Seo, Minchul;Lee, Joon Ha;Kim, In-Woo;Kim, Mi-Ae;Hwang, Jae-Sam
    • Journal of Life Science
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    • v.31 no.11
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    • pp.987-994
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    • 2021
  • Our previous studies have reported that antimicrobial peptides (AMPs) derived from the larvae of white-spotted flower chafer (Protaetia brevitarsis seulensis) exert anti-inflammatory and neuroprotective activities. This study explored the anti-inflammatory effects of protaetiamycine 9 (CVLKKAYFLTNLKLRG-NH2), a novel AMP, derived from P. b. seulensis against lipopolysaccharide (LPS)-mediated inflammatory response in RAW264.7 macrophage cells. Protaetiamycine 9 (25, 50, 75, and 100 ㎍/ml) did not cause cytotoxic effects against RAW264.7 cells. The RAW264.7 cells were pre-treated with various concentrations of protaetiamycine 9 (25-100 ㎍/ml) for 1 hr and then exposed to LPS (100 ng/ml) for 24 hr. Protaetiamycine 9 treatments decreased the LPS-induced secretion of inflammatory mediators, such as nitric oxide (NO), in a dose-dependent manner. Protaetiamycine 9 (25-100 ㎍/ml) effectively downregulated the LPS-induced increase in mRNA and the protein expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2), which are involved in the production of inflammatory mediators. Protaetiamycine 9 also suppressed the production and gene expression of pro-inflammatory cytokines, including interleukin (IL)-6 and IL-1β, compared to the presence of LPS alone. Furthermore, protaetiamycine 9 inhibited the degradation of inhibitory kappa B alpha (IκB-α) and the phosphorylation of mitogen-activated protein kinases (MAPKs), such as extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38. In conclusion, these results suggest that protaetiamycine 9 exhibits LPS-mediated inflammatory responses by blocking IκB-α degradation and MAPK phosphorylation.

GENE EXPRESSION PATTERNS INDUCED BY $TAXOL^{(R)}$ AND CYCLOSPORIN A IN ORAL SQUAMOUS CELL CARCINOMA CELL LINE USING CDNA MICROARRAY (cDNA Microarray를 이용한 구강편평세포암종 세포주에서 $Taxol^{(R)}$과 Cyclosporin A로 유도된 유전자 발현양상)

  • Kim, Yong-Kwan;Lee, Jae-Hoon;Kim, Chul-Hwan
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.28 no.3
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    • pp.202-212
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    • 2006
  • It is well-known that paclitaxel($Taxol^{(R)}$), which is extracted from the pacific and English yew, has been used as a chemotherapeutic agent for ovarian carcinoma and advanced breast carcinoma and Cyclosporin A, which is highly lipophilic cyclic peptide and isolated from a fungus, has been also used as an useful immunosuppressive drug after transplantation and is associated with cellular apoptosis. Since 1953, in which James Watson, Rosalind Franklin and Francis Crick discovered the double helical structure of DNA, a few kinds of techniques for identifying gene expression have been developed. In postgenomic period, many of researchers have used the DNA microarray which is high throughput screening technique to screen large numbers of gene expression simultaneously. In this study, we searched and screened the gene expression in the oral squamous cell carcinoma cell lines treated with $Taxol^{(R)}$, cyclosporin or cyclosporin combined with $Taxol^{(R)}$ using cDNA microarray. The results were as following; 1. It was useful that the appropriate concentration of Cyclosporin A and $Taxol^{(R)}$ used in oral squamous cell carcinoma cell line was under 1${\mu}g/ml$ and 3${\mu}g/ml$. 2. In the experimental group in which $Taxol^{(R)}$ and $Taxol^{(R)}$ + Cyclosporin A were used, the cell growth was extremely decreased. 3. In the group in which Cyclosporin A was used, the MTT assay was rarely decreased which means the activity of succinyl dehydrogenase is remained in mitochondria but in the group in which the mixture of Cyclosporin A and $Taxol^{(R)}$ were used, the MTT assay was extremely decreased. 4. In the each group in which Cyclosporin A(3 ${\mu}g/ml$) and $Taxol^{(R)}$(1 ${\mu}g/ml$) were used, the cell arrest was appeared in $G_2/M$ phase and in the group in which $Taxol^{(R)}$(3 ${\mu}g/ml$) was used, the cell arrest was appeared in both S phase and $G_2/M$ phase. 5. In the oral squamous cell carcinoma cell line treated with $Taxol^{(R)}$, several genes including ANGPTL4, RALBP1 and TXNRD1, associated with apoptosis, SUI1, MAC30, RRAGA and CTGF, related with cell growth, HUS1 and DUSP5, related with cell cycle and proliferation, ATF4 and CEBPG, associated with transcription factor, BTG1 and VEGF, associated with angiogenesis, FDPS, FCER1G, GPA33 and EPHA4 associated with signal transduction and receptor activity and AKR1C2 and UGTA10 related with carcinogenesis were detected in increased levels. The genes that showed increaced expression in the oral squamous cell carcinoma cell line treated with Cyclosporin A were CYR61, SERPINB2, SSR3 and UPA3A which are known as genes associated with cell growth, carcinogenesis, receptor activity and transcription factor. The genes expressed in the HN22 cell line treated with cyclosporin combined with $taxol^{(R)}$ were ALCAM and GTSE1 associated with cancer invasiveness and cell cycle regulation.