scholarly journals Use of Green Fluorescent Protein/Flp Recombinase Fusion Protein and Flow Cytometric Sorting to Enrich for Cells Undergoing Flp-Mediated Recombination

BioTechniques ◽  
2000 ◽  
Vol 28 (5) ◽  
pp. 966-974
Author(s):  
Daniel E. Sabath ◽  
Mi-Hyun Shim
1997 ◽  
Vol 139 (6) ◽  
pp. 1465-1476 ◽  
Author(s):  
Norio Sakai ◽  
Keiko Sasaki ◽  
Natsu Ikegaki ◽  
Yasuhito Shirai ◽  
Yoshitaka Ono ◽  
...  

We expressed the γ-subspecies of protein kinase C (γ-PKC) fused with green fluorescent protein (GFP) in various cell lines and observed the movement of this fusion protein in living cells under a confocal laser scanning fluorescent microscope. γ-PKC–GFP fusion protein had enzymological properties very similar to that of native γ-PKC. The fluorescence of γ-PKC– GFP was observed throughout the cytoplasm in transiently transfected COS-7 cells. Stimulation by an active phorbol ester (12-O-tetradecanoylphorbol 13-acetate [TPA]) but not by an inactive phorbol ester (4α-phorbol 12, 13-didecanoate) induced a significant translocation of γ-PKC–GFP from cytoplasm to the plasma membrane. A23187, a Ca2+ ionophore, induced a more rapid translocation of γ-PKC–GFP than TPA. The A23187-induced translocation was abolished by elimination of extracellular and intracellular Ca2+. TPA- induced translocation of γ-PKC–GFP was unidirected, while Ca2+ ionophore–induced translocation was reversible; that is, γ-PKC–GFP translocated to the membrane returned to the cytosol and finally accumulated as patchy dots on the plasma membrane. To investigate the significance of C1 and C2 domains of γ-PKC in translocation, we expressed mutant γ-PKC–GFP fusion protein in which the two cysteine rich regions in the C1 region were disrupted (designated as BS 238) or the C2 region was deleted (BS 239). BS 238 mutant was translocated by Ca2+ ionophore but not by TPA. In contrast, BS 239 mutant was translocated by TPA but not by Ca2+ ionophore. To examine the translocation of γ-PKC–GFP under physiological conditions, we expressed it in NG-108 cells, N-methyl-d-aspartate (NMDA) receptor–transfected COS-7 cells, or CHO cells expressing metabotropic glutamate receptor 1 (CHO/mGluR1 cells). In NG-108 cells , K+ depolarization induced rapid translocation of γ-PKC–GFP. In NMDA receptor–transfected COS-7 cells, application of NMDA plus glycine also translocated γ-PKC–GFP. Furthermore, rapid translocation and sequential retranslocation of γ-PKC–GFP were observed in CHO/ mGluR1 cells on stimulation with the receptor. Neither cytochalasin D nor colchicine affected the translocation of γ-PKC–GFP, indicating that translocation of γ-PKC was independent of actin and microtubule. γ-PKC–GFP fusion protein is a useful tool for investigating the molecular mechanism of γ-PKC translocation and the role of γ-PKC in the central nervous system.


2006 ◽  
Vol 309 (1-2) ◽  
pp. 130-138 ◽  
Author(s):  
Qi-Lai Huang ◽  
Cheng Chen ◽  
Yun-Zi Chen ◽  
Chen-Guang Gong ◽  
Lin Cao ◽  
...  

2005 ◽  
Vol 86 (12) ◽  
pp. 3201-3208 ◽  
Author(s):  
Long P. Le ◽  
Jing Li ◽  
Vladimir V. Ternovoi ◽  
Gene P. Siegal ◽  
David T. Curiel

Canine adenovirus type 2 (CAV2) has become an attractive vector for gene therapy because of its non-pathogenicity and the lack of pre-existing neutralizing antibodies against this virus in the human population. Additionally, this vector has been proposed as a conditionally replicative adenovirus agent under the control of an osteocalcin promoter for evaluation in a syngeneic, immunocompetent canine model with spontaneous osteosarcoma. In this study, a CAV2 vector labelled with the fluorescent capsid fusion protein IX–enhanced green fluorescent protein (pIX–EGFP) was developed. Expression of the fluorescent fusion-protein label in infected cells with proper nuclear localization, and incorporation into virions, could be detected. The labelled virions could be visualized by fluorescence microscopy; this was applicable to the tracking of CAV2 infection, as well as localizing the distribution of the vector in tissues. Expression of pIX–EGFP could be exploited to detect the replication and spread of CAV2. These results indicate that pIX can serve as a platform for incorporation of heterologous proteins in the context of a canine adenovirus xenotype. It is believed that capsid-labelled CAV2 has utility for vector-development studies and for monitoring CAV2-based oncolytic adenovirus replication.


2002 ◽  
Vol 7 (4) ◽  
pp. 325-332 ◽  
Author(s):  
Arno Pol ◽  
Fred Van Ruissen ◽  
Joost Schalkwijk

Inflamed epidermis (psoriasis, wound healing, ultraviolet-irradiated skin) harbors keratinocytes that are hyperproliferative and display an abnormal differentiation program. A distinct feature of this so-called regenerative maturation pathway is the expression of proteins such as the cytokeratins CK6, CK16, and CK17 and the antiinflammatory protein SKALP/elafin. These proteins are absent in normal skin but highly induced in lesional psoriatic skin. Expression of these genes can be used as a surrogate marker for psoriasis in drug-screening procedures of large compound libraries. The aim of this study was to develop a keratinocyte cell line that contained a reporter gene under the control of a psoriasis-associated endogenous promoter and demonstrate its use in an assay suitable for screening. We generated a stably transfected keratinocyte cell line that expresses enhanced green fluorescent protein (EGFP), under the control of a 0.8-kb fragment derived from the promoter of the SKALP/elafin gene, which confers high levels of tissue-specific expression at the mRNA level. Induction of the SKALP promoter by tumor necrosis factor-ca resulted in increased expression levels of the secreted SKALP-EGFP fusion protein as assessed by direct readout of fluorescence and fluorescence polarization in 96-well cell culture plates. The fold stimulation of the reporter gene was comparable to that of the endogenous SKALP gene as assessed by enzyme-linked immunosorbent assay. Although the dynamic range of the screening system is limited, the small standard deviation yields a Z factor of 0.49. This indicates that the assay is suitable as a high-throughput screen, and provides proof of the concept that a secreted EGFP fusion protein under the control of a physiologically relevant endogenous promoter can be used as a fluorescence-based high-throughput screen for differentiation-modifying or antiinflammatory compounds that act via the keratinocyte.


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