scholarly journals Expression of a functional recombinant vascular endothelial growth factor 165 (VEGF165) in Arabidopsis thaliana

2018 ◽  
Vol 44 (3) ◽  
pp. 254-260
Author(s):  
Weidong Qiang ◽  
Xue Feng ◽  
Yixin Li ◽  
Xinxin Lan ◽  
Kun Ji ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Cell Activity ◽  
Downstream Processing ◽  
Coding Region ◽  
Specific Expression ◽  
Plant Seed ◽  
Huvec Cell ◽  
Plant Seed Oil ◽  
High Level

Abstract Objective Targeting the protein of interest to a particular tissue to achieve high-level expression is an important strategy to increase expression efficiency. The use of the plant seed oil body as a bioreactor can not only increase the amount of target protein, but also reduce the cost of downstream processing. Methods VEGF165 was expressed in Arabidopsis thaliana seeds via oilbody fusion technology. The pKO-VEGF165 vector was construted and transformed into A. thaliana seeds. T3 transgenic seeds was detected by SDS-PAGE and western blot methods. The cell activity was tested by MTT methods. Result The phaseolin promoter was used to drive seed-specific expression of the VEGF165 gene in transgenic A. thaliana. The coding region of VEGF165 was fused to the Arabidopsis oleosin sequence to target the protein to the oil bodies in the seeds of transgenic plants. The T-DNA region of recombinant plasmid pKO-VEGF165 was shifted to A. thaliana seeds via the floral-dip method. Protein was analyzed by electrophoresis and protein hybridization analyses. Finally, MTT assays showed that the oleosin-VEGF165 fusion protein played a part in the proliferation of HUVEC cells in vitro. Conclusion Oleosin-VEGF165 was successfully expressed and it had stimulated HUVEC cell proliferation activity.

scholarly journals Impact of Y143 HIV-1 Integrase Mutations on Resistance to Raltegravir In Vitro and In Vivo

2009 ◽  
Vol 54 (1) ◽  
pp. 491-501 ◽  
Author(s):  
Olivier Delelis ◽  
Sylvain Thierry ◽  
Frédéric Subra ◽  
Françoise Simon ◽  
Isabelle Malet ◽  
...  
Keyword(s):  
Viral Genome ◽  
Effective Concentration ◽  
Coding Region ◽  
Delayed Emergence ◽  
Infected Cells ◽  
High Level ◽  
Emergence Of Resistance ◽  
Hiv 1

ABSTRACT Integrase (IN), the HIV-1 enzyme responsible for the integration of the viral genome into the chromosomes of infected cells, is the target of the recently approved antiviral raltegravir (RAL). Despite this drug's activity against viruses resistant to other antiretrovirals, failures of raltegravir therapy were observed, in association with the emergence of resistance due to mutations in the integrase coding region. Two pathways involving primary mutations on residues N155 and Q148 have been characterized. It was suggested that mutations at residue Y143 might constitute a third primary pathway for resistance. The aims of this study were to investigate the susceptibility of HIV-1 Y143R/C mutants to raltegravir and to determine the effects of these mutations on the IN-mediated reactions. Our observations demonstrate that Y143R/C mutants are strongly impaired for both of these activities in vitro. However, Y143R/C activity can be kinetically restored, thereby reproducing the effect of the secondary G140S mutation that rescues the defect associated with the Q148R/H mutants. A molecular modeling study confirmed that Y143R/C mutations play a role similar to that determined for Q148R/H mutations. In the viral replicative context, this defect leads to a partial block of integration responsible for a weak replicative capacity. Nevertheless, the Y143 mutant presented a high level of resistance to raltegravir. Furthermore, the 50% effective concentration (EC50) determined for Y143R/C mutants was significantly higher than that obtained with G140S/Q148R mutants. Altogether our results not only show that the mutation at position Y143 is one of the mechanisms conferring resistance to RAL but also explain the delayed emergence of this mutation.

scholarly journals Structure and tissue-specific expression of the Drosophila melanogaster organellar-type Ca2+-ATPase gene

1995 ◽  
Vol 310 (3) ◽  
pp. 757-763 ◽  
Author(s):  
A Magyar ◽  
E Bakos ◽  
A Váradi
Keyword(s):  
Drosophila Melanogaster ◽  
Transcription Initiation ◽  
Initiation Site ◽  
Drosophila Genome ◽  
Coding Region ◽  
Specific Expression ◽  
S1 Nuclease ◽  
Protein Coding ◽  
Atpase Gene ◽  
High Level

A 14 kb genomic clone covering the organellar-type Ca(2+)-ATPase gene of Drosophila melanogaster has been isolated and characterized. The sequence of a 7132 bp region extending from 1.1 kb 5′ upstream of the initiation ATG codon over the polyadenylation signal at the 3′ end has been determined. The gene consists of nine exons including one with an exceptional size of 2172 bp representing 72% of the protein coding region. Introns are relatively small (< 100 bp) except for the 3′ intron which has a size of 2239 bp, an exceptionally large size among Drosophila introns. Five of the introns are in the same positions in Drosophila, Artemia and rabbit SERCA1 Ca(2+)-ATPase genes. There is only one organellar-type Ca(2+)-ATPase gene in the Drosophila genome, as was shown by Southern-blot analysis [Váradi, Gilmore-Hebert and Benz (1989) FEBS Lett. 258, 203-207] and by chromosomal localization [Magyar and Váradi (1990) Biochem. Biophys. Res. Commun. 173, 872-877]. Primer extension and S1-nuclease assays revealed a potential transcription initiation site 876 bp upstream of the translation initiation ATG with a TATA-box 23 bp upstream of this site. Analysis of the 5′ region of the Drosophila organellar-type Ca(2+)-ATPase gene suggests the presence of potential recognition sequences of various muscle-specific transcription factors and shows a region with remarkable similarity to that in the rabbit SERCA2 gene. The tissue distribution of expression of the organellar-type Ca(2+)-ATPase gene has been studied by in situ RNA-RNA hybridization on microscopic sections. A low mRNA abundance can be detected in each tissue of adult flies, suggesting a housekeeping function for the gene. On the other hand a pronounced tissue specificity of expression has also been found as the organellar-type Ca(2+)-ATPase is expressed at a very high level in cell bodies of the central nervous system and in various muscles.

GATA-1 Binding to Exon 1 Directs High Level Erythroid-Specific Expression of the Human Protoporphyrinogen Oxidase Gene.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1682-1682
Author(s):  
Karen M.K. de Vooght ◽  
Richard van Wijk ◽  
Wouter W. van Solinge
Keyword(s):  
Transcriptional Regulation ◽  
Promoter Activity ◽  
K562 Cells ◽  
Promoter Strength ◽  
Specific Expression ◽  
Oxidase Gene ◽  
Protoporphyrinogen Oxidase ◽  
Exon 1 ◽  
High Level

Abstract Protoporphyrinogen oxidase (PPOX), the penultimate enzyme in the heme biosynthetic pathway, catalyzes the six-electron oxidation of protoporphyrinogen IX to protoporphyrin IX. Like other heme biosynthetic proteins, PPOX is involved in synthesizing heme for red cells (erythroid-specific expression) and as a cofactor for the respiratory cytochromes (housekeeping expression). To date, little is known about transcriptional regulation of the human PPOX gene (PPOX). We established the molecular basis for erythroid-specific expression of PPOX. Using transient in vitro transfection assays in human erythroleukemic K562 cells we studied tissue-specific expression of PPOX. We found that reporter constructs lacking exon 1 showed a 75% reduction in promoter strength in K562 cells (Figure, no 1 and 2). Hence, in vitro high-level erythroid-specific expression of PPOX is dependent on the presence of exon 1. Examination of erythroid-specific regulatory elements in exon 1 revealed two GATA-1 sites, one consensus (A/T)GATA(A/G) site (GATA-1_II AGATAA) and one non-consensus site, deviating at the first nucleotide (GATA-1_I, CGATAG). To study the relative contribution of these two GATA-1 sites to erythroid-specific transcriptional regulation, we performed in vitro transfections of wild-type and mutant (GATA → GTTA) reporter plasmids in K562 cells. We found that the highest level of transcription depended on the integrity of both sites (Figure, no 5). The consensus GATA-1_II site contributed the most to promoter strength (Figure, no 4). Subsequent electrophoretic mobility shift assay and supershift experiments using K562 nuclear extracts demonstrated that both GATA sites were able to bind GATA-1 in vitro. Our experiments showed that exon 1 was dispensable for PPOX promoter activity in human hepatoma HepG2 cells. Interestingly, in HeLa human cervical carcinoma cells the presence of exon 1 decreased promoter activity. Conclusively, exon 1 of the human PPOX gene contains two GATA-1 binding sites, which are required for high level erythroid-specific expression of PPOX and, in addition, bind GATA-1 in vitro. Our results contribute to a better understanding of the molecular mechanisms involved in differential regulation of the human PPOX promoter in erythroid and non-erythroid cells. Figure Figure

scholarly journals Identification of Novel Polyphenolic Inhibitors of Shikimate Dehydrogenase (AroE)

2014 ◽  
Vol 19 (7) ◽  
pp. 1090-1098 ◽  
Author(s):  
James Peek ◽  
Thomas Shi ◽  
Dinesh Christendat
Keyword(s):  
Arabidopsis Thaliana ◽  
Pseudomonas Putida ◽  
Antimicrobial Agents ◽  
Epigallocatechin Gallate ◽  
Shikimate Dehydrogenase ◽  
Epicatechin Gallate ◽  
Essential Nature ◽  
Structural Conservation ◽  
High Level

Shikimate dehydrogenase (AroE) is an attractive target for herbicides and antimicrobial agents due to its conserved and essential nature in plants, fungi, and bacteria. Here, we have performed an in vitro screen using a collection of more than 5500 compounds and identified 24 novel inhibitors of AroE from Pseudomonas putida. The IC50 values for the two most potent inhibitors we identified, epigallocatechin gallate (EGCG) and epicatechin gallate (ECG), were 3.0 ± 0.2 µM and 3.7 ± 0.5 µM, respectively. Based on the high level of structural conservation between AroE orthologs, we predicted that the identified compounds would also inhibit AroE enzymes from other organisms. Consistent with this hypothesis, we found that EGCG and ECG inhibit the AroE domain of the bifunctional dehydroquinate dehydratase-shikimate dehydrogenase (DHQ-SDH) from Arabidopsis thaliana with IC50 values of 2.1 ± 0.3 µM and 2.0 ± 0.2 µM, respectively.

scholarly journals CRISPR/Cas9 Deletion of SOX2 Regulatory Region 2 (SRR2) Decreases SOX2 Malignant Activity in Glioblastoma

Cancers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1574
Author(s):  
Ander Saenz-Antoñanzas ◽  
Veronica Moncho-Amor ◽  
Jaione Auzmendi-Iriarte ◽  
Alejandro Elua-Pinin ◽  
Karine Rizzoti ◽  
...  
Keyword(s):  
Adult Stem Cells ◽  
Regulatory Region ◽  
Cell Activity ◽  
Coding Region ◽  
Glioblastoma Cells ◽  
Tumor Initiating Cells ◽  
Sox2 Expression ◽  
Stem Cell Activity

SOX2 is a transcription factor associated with stem cell activity in several tissues. In cancer, SOX2 expression is increased in samples from several malignancies, including glioblastoma, and high SOX2 levels are associated with the population of tumor-initiating cells and with poor patient outcome. Therefore, understanding how SOX2 is regulated in cancer cells is relevant to tackle tumorigenesis. The SOX2 regulatory region 2(SRR2) is located downstream of the SOX2 coding region and mediates SOX2 expression in embryonic and adult stem cells. In this study, we deleted SRR2 using CRISPR/Cas9 in glioblastoma cells. Importantly, SRR2-deleted glioblastoma cells presented reduced SOX2 expression and decreased proliferative activity and self-renewal capacity in vitro. In line with these results, SRR2-deleted glioblastoma cells displayed decreased tumor initiation and growth in vivo. These effects correlated with an elevation of p21CIP1 cell cycle and p27KIP1 quiescence regulators. In conclusion, our data reveal that SRR2 deletion halts malignant activity of SOX2 and confirms that the SRR2 enhancer regulates SOX2 expression in cancer.

scholarly journals Direct proof that the primary site of action of cytochalasin on cell motility processes is actin.

1992 ◽  
Vol 116 (4) ◽  
pp. 933-941 ◽  
Author(s):  
H Ohmori ◽  
S Toyama ◽  
S Toyama
Keyword(s):  
Cell Motility ◽  
Direct Proof ◽  
Primary Site ◽  
Coding Region ◽  
Beta Actin ◽  
Site Of Action ◽  
Altered Form ◽  
High Level

We have previously described the isolation of a mutant KB cell (Cyt 1 mutant) resistant to the cytotoxic effect of cytochalasin B (CB). The Cyt 1 mutant carries an altered form of beta-actin (beta'-actin) and lacks normal beta-actin (Toyama, S., and S. Toyama. 1984. Cell. 37:609-614). Increased resistance of the Cyt 1 mutant to CB in vivo is reflected in altered properties of beta'-actin in vitro (Toyama, S., and S. Toyama. 1988. J. Cell Biol. 107:1499-1504). Here, we show that the mutation in beta-actin is solely responsible for the cytochalasin-resistant phenotype of the Cyt mutant. We have isolated a cDNA clone encoding beta'-actin from Cyt 1 cells. Sequence analysis reveals two mutations in the coding region that substitute two amino acid residues (Val139----Met and Ala295----Asp). Expression of the beta'-actin cDNA confers cytochalasin resistance upon transformed cytochalasin-sensitive KB cells. Levels of resistance to CB in the transformed cell clones correlate well with amounts of beta'-actin polypeptide. Both of the two mutations in beta'-actin are necessary for the high level expression of cytochalasin resistance. Overall, we conclude that the primary site of action of cytochalasin on cell motility processes in vivo is actin.

scholarly journals REF2 encodes an RNA-binding protein directly involved in yeast mRNA 3'-end formation.

1995 ◽  
Vol 15 (3) ◽  
pp. 1689-1697 ◽  
Author(s):  
R Russnak ◽  
K W Nehrke ◽  
T Platt
Keyword(s):  
Rna Binding ◽  
Lacz Gene ◽  
Coding Region ◽  
Binding Characteristics ◽  
Starting Point ◽  
Cellular Mrnas ◽  
General Defect ◽  
High Level ◽  
A Site

The Saccharomyces cerevisiae mutant ref2-1 (REF = RNA end formation) was originally identified by a genetic strategy predicted to detect decreases in the use of a CYC1 poly(A) site interposed within the intron of an ACT1-HIS4 fusion reporter gene. Direct RNA analysis now proves this effect and also demonstrates the trans action of the REF2 gene product on cryptic poly(A) sites located within the coding region of a plasmid-borne ACT1-lacZ gene. Despite impaired growth of ref2 strains, possibly because of a general defect in the efficiency of mRNA 3'-end processing, the steady-state characteristics of a variety of normal cellular mRNAs remain unaffected. Sequencing of the complementing gene predicts the Ref2p product to be a novel, basic protein of 429 amino acids (M(r), 48,000) with a high-level lysine/serine content and some unusual features. Analysis in vitro, with a number of defined RNA substrates, confirms that efficient use of weak poly(A) sites requires Ref2p: endonucleolytic cleavage is carried out accurately but at significantly lower rates in extracts prepared from delta ref2 cells. The addition of purified, epitope-tagged Ref2p (Ref2pF) reestablishes wild-type levels of activity in these extracts, demonstrating direct involvement of this protein in the cleavage step of 3' mRNA processing. Together with the RNA-binding characteristics of Ref2pF in vitro, our results support an important contributing role for the REF2 locus in 3'-end processing. As the first gene genetically identified to participate in mRNA 3'-end maturation prior to the final polyadenylation step, REF2 provides an ideal starting point for identifying related genes in this event.

scholarly journals Analysis of the thrombopoietin receptor (MPL) promoter implicates GATA and Ets proteins in the coregulation of megakaryocyte-specific genes

Blood ◽  
1996 ◽  
Vol 87 (11) ◽  
pp. 4678-4685 ◽  
Author(s):  
S Deveaux ◽  
A Filipe ◽  
V Lemarchandel ◽  
J Ghysdael ◽  
PH Romeo ◽  
...  
Keyword(s):  
Molecular Basis ◽  
Specific Expression ◽  
Ets Proteins ◽  
Thrombopoietin Receptor ◽  
Early Markers ◽  
Hel Cells ◽  
Ets Family ◽  
High Level ◽  
Gata Motif

he MPL gene codes for the thrombopoietin receptor, whose ligand specifically controls megakaryocytic differentiation. To understand the molecular basis for the megakaryocyte-specific expression of MPL, we analyzed the promoter of this gene. A 200 bp fragment is sufficient for high-level specific expression. This fragment can bind several trans- acting factors in vitro, including GATA-1 and members of the Ets family. GATA-1 binds with low affinity to a unique GATA motif at -70 in the MPL promoter, and destruction of this site yields only a modest decrease in expression level in HEL cells. Ets proteins also bind with low affinity to two sites. One is located at position -15 and its destruction reduces expression to 50%; the other is located immediately downstream of the GATA motif and plays a crucial role in expression of the promoter in HEL cells, as its inactivation reduces expression to 15%. Furthermore, GATA-1 and two Ets proteins, Ets-1 and Fli-1, can trans-activate the MPL promoter in heterologous cells. The effects of GATA-1 and these two Ets proteins are additive. Together with our previous results on the glycoprotein IIb (GpIIb) promoter, this study indicates a molecular basis for the coregulation of early markers of megakaryocyte differentiation.

scholarly journals Mutations in the EDR1 Gene Alter the Response of Arabidopsis thaliana to Phytophthora infestans and the Bacterial PAMPs flg22 and elf18

2015 ◽  
Vol 28 (2) ◽  
pp. 122-133 ◽  
Author(s):  
Katrin Geissler ◽  
Lennart Eschen-Lippold ◽  
Kai Naumann ◽  
Korbinian Schneeberger ◽  
Detlef Weigel ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Phytophthora Infestans ◽  
Kinase Domain ◽  
Negative Regulator ◽  
Single Amino Acid ◽  
Nonhost Resistance ◽  
Coding Region ◽  
Callose Deposition ◽  
Knock Out

Mechanistically, nonhost resistance of Arabidopsis thaliana against the oomycete Phytophthora infestans is not well understood. Besides PEN2 and PEN3, which contribute to penetration resistance, no further components have been identified so far. In an ethylmethane sulphonate–mutant screen, we mutagenized pen2-1 and screened for mutants with an altered response to infection by P. infestans. One of the mutants obtained, enhanced response to Phytophthora infestans6 (erp6), was analyzed. Whole-genome sequencing of erp6 revealed a single nucleotide polymorphism in the coding region of the kinase domain of At1g08720, which encodes the putative MAPKKK ENHANCED DISEASE RESISTANCE1 (EDR1). We demonstrate that three independent lines with knock-out alleles of edr1 mount an enhanced response to P. infestans inoculation, mediated by increased salicylic acid signaling and callose deposition. Moreover, we show that the single amino acid substitution in erp6 causes the loss of in vitro autophosphorylation activity of EDR1. Furthermore, growth inhibition experiments suggest a so-far-unknown involvement of EDR1 in the response to the pathogen-associated molecular patterns flg22 and elf18. We conclude that EDR1 contributes to the defense response of A. thaliana against P. infestans. Our data position EDR1 as a negative regulator in postinvasive nonhost resistance.

Sign in / Sign up

Export Citation Format

Share Document