Secretion of foreign proteins mediated by chicken lysozyme gene regulatory sequences

2002 ◽  
Vol 80 (6) ◽  
pp. 777-788 ◽  
Author(s):  
Gregory R Lampard ◽  
Ann M. Verrinder Gibbins

Exploitation of the insulating properties of the complete chicken lysozyme gene domain may facilitate the production of transgenic chicken bioreactors with the capacity to deposit valuable proteins in the egg white. Chimeric genes consisting of the chicken lysozyme gene regulatory sequences and sequences encoding foreign proteins could be inserted randomly into the chicken genome and retain appropriate expression levels. The research reported here established that chicken lysozyme gene regulatory sequences can be used to direct the production and secretion of green fluorescent protein (used as a reporter protein) in transiently transfected chicken blastodermal cells. Attempts to verify these findings in transgenic hens are currently in progress. To provide a rapid means of generating constructs encoding other foreign proteins under the control of lysozyme gene regulatory sequences that can facilitate the secretion of heterologous proteins in vivo, a generic lysozyme gene regulatory scaffold was created using a poxvirus-mediated gene targeting system.Key words: chicken lysozyme gene, secretion, homologous recombination.

2012 ◽  
Vol 108 (09) ◽  
pp. 427-434 ◽  
Author(s):  
Richard J. Fish ◽  
Marguerite Neerman-Arbez

SummaryHigh circulating fibrinogen levels correlate with cardiovascular disease (CVD) risk. Fibrinogen levels vary between people and also change in response to physiological and environmental stimuli. A modest proportion of the variation in fibrinogen levels can be explained by genotype, inferring that variation in genomic sequences that regulate the fibri-nogen genes (FGA, FGB and FGG) may affect hepatic fibrinogen production and perhaps CVD risk. We previously identified a conserved liver enhancer in the fibrinogen gene cluster (CNC12), between FGB and FGA. Genome-wide Chromatin immunoprecipitation-sequencing (ChIP-seq) demonstrated that transcription factors which bind fibrinogen gene promoters also interact with CNC12, as well as two potential fibrinogen enhancers (PFE), between FGA and FGG. Here we show that one of the PFE sequences has potent hepatocyte enhancer activity. Using a luciferase reporter gene system, we found that PFE2 enhances minimal promoter- and FGA promoter-driven gene expression in hepatoma cells, regardless of its orientation with respect to the promoters. A region within PFE2 bears a short series of conserved nucleotides which maintain enhancer activity without flanking sequence. We also demonstrate that PFE2 is a liver enhancer in vivo, driving enhanced green fluorescent protein expression in transgenic zebrafish larval livers. Our study shows that combining public domain ChIP-seq data with in vitro and in vivo functional tests can identify novel fibrinogen gene cluster regulatory sequences. Variation in such elements could affect fibrinogen production and influence CVD risk.


2019 ◽  
pp. 525-530
Author(s):  
N. Lipták ◽  
Z. Bősze ◽  
L. Hiripi

Green Fluorescent protein (GFP) transgenic animals are accepted tools for studying various physiological processes, including organ development and cell migration. However, several in vivo studies claimed that GFP may impair transgenic animals’ health. Glomerulosclerosis was observed in transgenic mice and rabbits with ubiquitous reporter protein expression. Heart-specific GFP expression evoked dilated cardiomyopathy and altered cardiac function in transgenic mouse and zebrafish lines, respectively. Moreover, growth retardation and increased axon swelling were observed in GFP and yellow fluorescent protein (YFP) transgenic mice, respectively. This review will focus on the potential drawbacks of the applications of GFP transgenic animals in biomedical research.


1998 ◽  
Vol 180 (24) ◽  
pp. 6736-6742 ◽  
Author(s):  
Young-Sun Sohn ◽  
Cheon Seok Park ◽  
Sun-Bok Lee ◽  
Dewey D. Y. Ryu

ABSTRACT The Yarrowia lipolytica PMR1 gene (YlPMR1) is a Saccharomyces cerevisiae PMR1 homolog which encodes a putative secretory pathway Ca2+-ATPase. In this study, we investigated the effects of a YlPMR1 disruption on the processing and secretion of native and foreign proteins in Y. lipolytica and found variable responses by theYlPMR1-disrupted mutant depending on the protein. The secretion of 32-kDa mature alkaline extracellular protease (AEP) was dramatically decreased, and incompletely processed precursors were observed in the YlPMR1-disrupted mutant. A 36- and a 52-kDa premature AEP were secreted, and an intracellular 52-kDa premature AEP was also detected. The acid extracellular protease activity of theYlPMR1-disrupted mutant was increased by 60% compared to that of the wild-type strain. The inhibitory effect of mutations in secretory pathway Ca2+-ATPase genes on the secretion of rice α-amylase was also observed in the Y. lipolytica andS. cerevisiae PMR1-disrupted mutants. Unlike rice α-amylase, the secretion of Trichoderma reeseiendoglucanase I (EGI) was not influenced by the YlPMR1disruption. However, the secreted EGI from theYlPMR1-disrupted mutant had different characteristics than that of the control. While wild-type cells secreted the hyperglycosylated form of EGI, hyperglycosylation was completely absent in the YlPMR1-disrupted mutant. Our results indicate that the effects of the YlPMR1 disruption as manifested by the phenotypic response depend on the characteristics of the reporter protein in the recombinant yeast strain evaluated.


2009 ◽  
Vol 27 (15_suppl) ◽  
pp. e14557-e14557
Author(s):  
C. C. Olsen ◽  
F. Li ◽  
Z. He ◽  
W. Li ◽  
C. Li

e14557 Background: Apoptosis is a major form of tumor cells death during cytotoxic therapy. Understanding the kinetics of apoptosis would greatly facilitate development of more effective therapeutic approaches. In order to monitor apoptosis activities in vivo, we developed a novel bioluminescence-based reporter gene to detect caspase 3 activities, which are elevated at the execution phase of apoptosis. Methods: A caspase-3 reporter system was constructed by combining two different reporter proteins; green fluorescent protein (GFP) and firefly luciferase (FL) linked through multiple polyubiquitin domains with a caspase-3 recognition site. Under normal circumstances, the reporter proteins are rapidly degraded by the proteasome system.. During apoptosis, activated caspse 3 cleaves off the multi-ubiquitin domain from the reporter protein. This enable the GFP and luciferase fusion reporter to be stabilized and achieve a significant gain in GFP protein and luciferase activities, which in turn could be monitored both in vitro and in vivo. 4T1 cells transduced with CMV-luc or Caspase-3 reporter xenografts were treated with both chemotherapy and radiation therapy and monitored for apoptosis activity. Results: In vitro experiments demonstrated increased luciferase with increasing radiation dose reflective of apoptosis with background levels nearly undetectable. Taxol was associated with a time-dependent increase from 24 to 72hrs after drug exposure, indicating that apoptosis is a gradual, heterogeneous process. EGFP signal increased from 1.85% in controls to 80.6% in cells treated with 1uM Taxol. Xenografts showed nearly undetectable luciferase background with Cytoxan therapy resulting in a 90-fold increase, 10 Gy a 24 fold increase and fractionated RT (5Gy x3) with a 46-fold increase. Conclusions: We developed a novel in vivo caspase reporter based on the ubiquitous proteosome system of protein degradation and bioluminsecence imaging. This allowed us to assess activation of apoptosis in response to chemoradiation therapy in tissue culture and breast cancer xenografts over the course of 2–3 weeks, which has not been possible with other technologies. No significant financial relationships to disclose.


2007 ◽  
Vol 189 (18) ◽  
pp. 6564-6571 ◽  
Author(s):  
Jennifer S. Choy ◽  
Latt Latt Aung ◽  
A. Wali Karzai

ABSTRACT Bacterial trans translation is activated when translating ribosomes are unable to elongate or terminate properly. Small protein B (SmpB) and transfer-messenger RNA (tmRNA) are the two known factors required for and dedicated to trans translation. tmRNA, encoded by the ssrA gene, is a bifunctional molecule that acts both as a tRNA and as an mRNA during trans translation. The functions of tmRNA ensure that stalled ribosomes are rescued, the causative defective mRNAs are degraded, and the incomplete polypeptides are marked for targeted proteolysis. We present in vivo and in vitro evidence that demonstrates a direct role for the Lon ATP-dependent protease in the degradation of tmRNA-tagged proteins. In an endogenous protein tagging assay, lon mutants accumulated excessive levels of tmRNA-tagged proteins. In a reporter protein tagging assay with λ-CI-N, the protein product of a nonstop mRNA construct designed to activate trans translation, lon mutant cells efficiently tagged the reporter protein, but the tagged protein exhibited increased stability. Similarly, a green fluorescent protein (GFP) construct containing a hard-coded C-terminal tmRNA tag (GFP-SsrA) exhibited increased stability in lon mutant cells. Most significantly, highly purified Lon preferentially degraded the tmRNA-tagged forms of proteins compared to the untagged forms. Based on these results, we conclude that Lon protease participates directly in the degradation of tmRNA-tagged proteins.


2016 ◽  
Vol 8 (10) ◽  
pp. 63
Author(s):  
Saisai Wang ◽  
Yali Wang ◽  
Dan Shen ◽  
Li Zhang ◽  
Songlei Xue ◽  
...  

<p>Transposon mediated transfection is a promising, safe, and convenient way to generate transgenic chicken compared with virus-mediated technology and the in vitro modification of primordial germ cells (PGCs). To establish a simple method for in vivo transfection of chicken PGCs, we applied four different transposon systems (PB, SB, Tol2, and ZB) to investigate the gene transfer efficiency of chicken gonads via direct injection of a mixture of transposon and transposase plasmids and transfection reagent (polyethylenimine, PEI) into the subgerminal cavity of Hamburger and Hamilton stage 2-3 chick embryos. We also compared the effect of the amount of plasmids injected on the gene transfer efficiency of chicken gonads. We found that over 70% of the gonads were green fluorescent protein (GFP)-positive across all four transposon groups, and that the proportion of GFP-positive gonads was not significantly different between different transposons. Some GFP positive cells in gonads were confirmed as germ cells by co-labeling with the germ cell specific antibody. We also found that the proportions of GFP-positive gonads decreased significantly with a decrease of plasmid dose from 100 ng to 20 or 50 ng. Here we revealed that a combination of transposons with PEI is a simple and efficient method for gene transfer into chicken gonads and able to transfect PGCs in vivo that could be used for the production of transgenic chickens.</p>


2012 ◽  
Vol 78 (9) ◽  
pp. 3051-3058 ◽  
Author(s):  
Hyeok-Jin Ko ◽  
Eunhye Park ◽  
Joseph Song ◽  
Taek Ho Yang ◽  
Hee Jong Lee ◽  
...  

ABSTRACTAutotransporters have been employed as the anchoring scaffold for cell surface display by replacing their passenger domains with heterologous proteins to be displayed. We adopted an autotransporter (YfaL) ofEscherichia colifor the cell surface display system. The critical regions in YfaL for surface display were identified for the construction of a ligation-independent cloning (LIC)-based display system. The designed system showed no detrimental effect on either the growth of the host cell or overexpressing heterologous proteins on the cell surface. We functionally displayed monomeric red fluorescent protein (mRFP1) as a reporter protein and diverse agarolytic enzymes fromSaccharophagus degradans2-40, including Aga86C and Aga86E, which previously had failed to be functional expressed. The system could display different sizes of proteins ranging from 25.3 to 143 kDa. We also attempted controlled release of the displayed proteins by incorporating a tobacco etch virus protease cleavage site into the C termini of the displayed proteins. The maximum level of the displayed protein was 6.1 × 104molecules per a single cell, which corresponds to 5.6% of the entire cell surface of actively growingE. coli.


2005 ◽  
Vol 79 (15) ◽  
pp. 9991-10002 ◽  
Author(s):  
Clarisse Valentin ◽  
Patrice Dunoyer ◽  
Guillaume Vetter ◽  
Catherine Schalk ◽  
André Dietrich ◽  
...  

ABSTRACT During infection, Beet necrotic yellow vein virus (BNYVV) particles localize transiently to the cytosolic surfaces of mitochondria. To understand the molecular basis and significance of this localization, we analyzed the targeting and membrane insertion properties of the viral proteins. ORF1 of BNYVV RNA-2 encodes the 21-kDa major coat protein, while ORF2 codes for a 75-kDa minor coat protein (P75) by readthrough of the ORF1 stop codon. Bioinformatic analysis highlighted a putative mitochondrial targeting sequence (MTS) as well as a major (TM1) and two minor (TM3 and TM4) transmembrane regions in the N-terminal part of the P75 readthrough domain. Deletion and gain-of-function analyses based on the localization of green fluorescent protein (GFP) fusions showed that the MTS was able to direct a reporter protein to mitochondria but that the protein was not persistently anchored to the organelles. GFP fused either to MTS and TM1 or to MTS and TM3-TM4 efficiently and specifically associated with mitochondria in vivo. The actual role of the individual domains in the interaction with the mitochondria seemed to be determined by the folding of P75. Anchoring assays to the outer membranes of isolated mitochondria, together with in vivo data, suggest that the TM3-TM4 domain is the membrane anchor in the context of full-length P75. All of the domains involved in mitochondrial targeting and anchoring were also indispensable for encapsidation, suggesting that the assembly of BNYVV particles occurs on mitochondria. Further data show that virions are subsequently released from mitochondria and accumulate in the cytosol.


2002 ◽  
Vol 363 (3) ◽  
pp. 737-744 ◽  
Author(s):  
Sandra PAIVA ◽  
Arthur L. KRUCKEBERG ◽  
Margarida CASAL

Green fluorescent protein (GFP) from Aequorea victoria was used as an in vivo reporter protein when fused to the C-terminus of the Jen1 lactate permease of Saccharomyces cerevisiae. The Jen1 protein tagged with GFP is a functional lactate transporter with a cellular abundance of 1670 molecules/cell, and a catalytic-centre activity of 123s−1. It is expressed and tagged to the plasma membrane under induction conditions. The factors involved in proper localization and turnover of Jen1p were revealed by expression of the Jen1p—GFP fusion protein in a set of strains bearing mutations in specific steps of the secretory and endocytic pathways. The chimaeric protein Jen1p—GFP is targeted to the plasma membrane via a Sec6-dependent process; upon treatment with glucose, it is endocytosed via END3 and targeted for degradation in the vacuole. Experiments performed in a Δdoa4 mutant strain showed that ubiquitination is associated with the turnover of the permease.


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