scholarly journals Examination of Listeria monocytogenes Intracellular Gene Expression by Using the Green Fluorescent Protein ofAequorea victoria

1999 ◽  
Vol 67 (4) ◽  
pp. 1844-1852 ◽  
Author(s):  
Nancy E. Freitag ◽  
Kathleen E. Jacobs
Keyword(s):  
Gene Expression ◽  
Tissue Culture ◽  
Green Fluorescent Protein ◽  
Listeria Monocytogenes ◽  
Host Cell ◽  
Fluorescent Protein ◽  
Culture Cells ◽  
Tissue Culture Cells ◽  
Green Fluorescent ◽  
Cell Spread

ABSTRACT The ActA protein of Listeria monocytogenes is an essential virulence factor and is required for intracellular bacterial motility and cell-to-cell spread. plcB, cotranscribed withactA, encodes a broad-specificity phospholipase C that contributes to lysis of host cell vacuoles and cell-to-cell spread. Construction of a transcriptional fusion between actA-plcBand the green fluorescent protein gene of Aequorea victoriahas facilitated the detailed examination of patterns ofactA/plcB expression within infected tissue culture cells.actA/plcB expression began approximately 30 min postinfection and was dependent upon entry of L. monocytogenes into the host cytosol. L. monocytogenes Δhly mutants, which are unable to escape from host cell vacuoles, did not express actA/plcB at detectable levels within infected tissue culture cells; however, complementation of thehly defect allowed entry of the bacteria into the host cytoplasm and subsequent actA/plcB expression. These results emphasize the ability of L. monocytogenes to sense the different host cell compartment environments encountered during the course of infection and to regulate virulence gene expression in response.

scholarly journals Lamin A/C Binding Protein LAP2α Is Required for Nuclear Anchorage of Retinoblastoma Protein

2002 ◽  
Vol 13 (12) ◽  
pp. 4401-4413 ◽  
Author(s):  
Ewa Markiewicz ◽  
Thomas Dechat ◽  
Roland Foisner ◽  
Roy. A Quinlan ◽  
Christopher J. Hutchison
Keyword(s):  
Tissue Culture ◽  
Fluorescent Protein ◽  
Solid Phase ◽  
Retinoblastoma Protein ◽  
Dominant Negative ◽  
Lamin A ◽  
Dependent Manner ◽  
Culture Cells ◽  
Tissue Culture Cells ◽  
Green Fluorescent

The phosphorylation-dependent anchorage of retinoblastoma protein Rb in the nucleus is essential for its function. We show that its pocket C domain is both necessary and sufficient for nuclear anchorage by transiently expressing green fluorescent protein (GFP) chimeras of Rb fragments in tissue culture cells and by extracting the cells with hypotonic solutions. Solid phase binding assays using glutathioneS-transferase-fusion of Rb pockets A, B, and C revealed a direct association of lamin C exclusively to pocket C. Lamina-associated polypeptide (LAP) 2α, a binding partner of lamins A/C, bound strongly to pocket C and weakly to pocket B. When LAP2α was immunoprecipitated from soluble nuclear fractions, lamins A/C and hypophosphorylated Rb were coprecipitated efficiently. Similarly, immunoprecipitation of expressed GFP-Rb fragments by using anti-GFP antibodies coprecipitated LAP2α, provided that pocket C was present in the GFP chimeras. On redistribution of endogenous lamin A/C and LAP2α into nuclear aggregates by overexpressing dominant negative lamin mutants in tissue culture cells, Rb was also sequestered into these aggregates. In primary skin fibroblasts, LAP2α is expressed in a growth-dependent manner. Anchorage of hypophosphorylated Rb in the nucleus was weakened significantly in the absence of LAP2α. Together, these data suggest that hypophosphorylated Rb is anchored in the nucleus by the interaction of pocket C with LAP2α–lamin A/C complexes.

scholarly journals Inactivating Gene Expression with Antisense Modified Oligonucleotides

Acta Naturae ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 101-105
Author(s):  
Sidney Altman ◽  
Carlos Angele-Martinez
Keyword(s):  
Gene Expression ◽  
Tissue Culture ◽  
Plasmodium Falciparum ◽  
Human Tissue ◽  
Target Gene ◽  
Modified Oligonucleotides ◽  
Modified Nucleotides ◽  
Culture Cells ◽  
Tissue Culture Cells

Modified nucleotides, including phosphoramidates and mesyl nucleotides, are very effective in inactivating gene expression in bacteria. Gyr A is the target gene in several organisms, including Plasmodium falciparum. Antisense reactions with bacteria infecting citrus plants are promising but incomplete. Human tissue culture cells assayed with a different target are also susceptible to the presence of mesyl oligonucleotides.

Green Fluorescent Protein: A Tool for Gene Expression and Cell Biology in Mycobacteria

2003 ◽  
pp. 245-260
Author(s):  
Laura E. Via ◽  
Subramanian Dhandayuthapani ◽  
Dusanka Deretic ◽  
V. Deretic
Keyword(s):  
Gene Expression ◽  
Green Fluorescent Protein ◽  
Cell Biology ◽  
Fluorescent Protein ◽  
Protein A ◽  
Green Fluorescent

Cryptococcus neoformans Differential Gene Expression Detected In Vitro and In Vivo with Green Fluorescent Protein

1999 ◽  
Vol 67 (4) ◽  
pp. 1812-1820
Author(s):  
Maurizio del Poeta ◽  
Dena L. Toffaletti ◽  
Thomas H. Rude ◽  
Sara D. Sparks ◽  
Joseph Heitman ◽  
...  
Keyword(s):  
Gene Expression ◽  
Green Fluorescent Protein ◽  
Cryptococcus Neoformans ◽  
Differential Gene Expression ◽  
Fluorescent Protein ◽  
Differential Gene ◽  
Green Fluorescent

scholarly journals The Green Fluorescent Protein Gene Functions as a Reporter of Gene Expression in Phanerochaete chrysosporium

2001 ◽  
Vol 67 (2) ◽  
pp. 948-955 ◽  
Author(s):  
Biao Ma ◽  
Mary B. Mayfield ◽  
Michael H. Gold
Keyword(s):  
Gene Expression ◽  
Green Fluorescent Protein ◽  
Phanerochaete Chrysosporium ◽  
Fluorescent Protein ◽  
Schizophyllum Commune ◽  
Extracellular Fluid ◽  
Gene Promoter ◽  
Green Fluorescent Protein Gene ◽  
Cell Extracts ◽  
Green Fluorescent

ABSTRACT The enhanced green fluorescent protein (GFP) gene (egfp) was used as a reporter of gene expression driven by the glyceraldehyde-p-dehydrogenase (gpd) gene promoter and the manganese peroxidase isozyme 1 (mnp1) gene promoter in Phanerochaete chrysosporium. Four different constructs were prepared. pUGGM3′ and pUGiGM3′ contain the P. chrysosporium gpd promoter fused upstream of the egfpcoding region, and pUMGM3′ and pUMiGM3′ contain the P. chrysosporium mnp1 promoter fused upstream of theegfp gene. In all constructs, the egfp gene was followed by the mnp1 gene 3′ untranslated region. In pUGGM3′ and pUMGM3′, the promoters were fused directly withegfp, whereas in pUGiGM3′ and pUMiGM3′, following the promoters, the first exon (6 bp), the first intron (55 bp), and part of the second exon (9 bp) of the gpd gene were inserted at the 5′ end of the egfp gene. All constructs were ligated into a plasmid containing the ura1 gene of Schizophyllum commune as a selectable marker and were used to transform a Ural1 auxotrophic strain of P. chrysosporium to prototrophy. Crude cell extracts were examined for GFP fluorescence, and where appropriate, the extracellular fluid was examined for MnP activity. The transformants containing a construct with an intron 5′ of theegfp gene (pUGiGM3′ and pUMiGM3′) exhibited maximal fluorescence under the appropriate conditions. The transformants containing constructs with no introns exhibited minimal or no fluorescence. Northern (RNA) blots indicated that the insertion of a 5′ intron resulted in more egfp RNA than was found in transformants carrying an intronless egfp. These results suggest that the presence of a 5′ intron affects the expression of theegfp gene in P. chrysosporium. The expression of GFP in the transformants carrying pUMiGM3′ paralled the expression of endogenous mnp with respect to nitrogen and Mn levels, suggesting that this construct will be useful in studyingcis-acting elements in the mnp1 gene promoter.

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