Detection of local ATP release from activated platelets using cell surface-attached firefly luciferase

1999 ◽  
Vol 276 (1) ◽  
pp. C267-C278 ◽  
Author(s):  
Reza Beigi ◽  
Eiry Kobatake ◽  
Masuo Aizawa ◽  
George R. Dubyak

We have developed a method for measuring the local concentration of ATP at the extracellular surface of live cells. This method relies on the specific attachment to the cell surface of a chimeric protein that consists of the IgG-binding domain of Staphylococcus aureus protein A fused in-frame with the complete sequence for firefly luciferase (proA-luc). Expression of proA-luc in Escherichia coli and its one-step affinity purification are straightforward. Attachment to cells is demonstrated to be specific and antibody dependent using several suspended and adherent cell types. Light production by cell surface-attached luciferase is continuous, linearly related to ATP concentration, and sufficient to provide nanomolar sensitivity. The spatial resolution of this method enables the observation of strictly local changes in extracellular ATP during its secretion from activated platelets. Furthermore, the activity of cell-attached luciferase is relatively refractory to the inclusion of nucleotidases in the medium, arguing for its effectiveness in cell systems possessing potent ecto-ATPases.

2005 ◽  
Vol 16 (8) ◽  
pp. 3659-3665 ◽  
Author(s):  
Patrizia Pellegatti ◽  
Simonetta Falzoni ◽  
Paolo Pinton ◽  
Rosario Rizzuto ◽  
Francesco Di Virgilio

ATP is emerging as an ubiquitous extracellular messenger. However, measurement of ATP concentrations in the pericellular space is problematic. To this aim, we have engineered a firefly luciferase-folate receptor chimeric protein that retains the N-terminal leader sequence and the C-terminal GPI anchor of the folate receptor. This chimeric protein, named plasma membrane luciferase (pmeLUC), is targeted and localized to the outer aspect of the plasma membrane. PmeLUC is sensitive to ATP in the low micromolar to millimolar level and is insensitive to all other nucleotides. To identify pathways for nonlytic ATP release, we transfected pmeLUC into cells expressing the recombinant or native P2X7 receptor (P2X7R). Both cell types release large amounts of ATP (100–200 μM) in response to P2X7R activation. This novel approach unveils a hitherto unsuspected nonlytic pathway for the release of large amounts of ATP that might contribute to spreading activation and recruitment of immune cells at inflammatory sites.


2008 ◽  
Vol 80 (23) ◽  
pp. 9316-9325 ◽  
Author(s):  
Yun Zhang ◽  
Gregory J. Phillips ◽  
Qingxi Li ◽  
Edward S. Yeung

1983 ◽  
Vol 60 (1) ◽  
pp. 251-266
Author(s):  
C.M. Chadwick ◽  
D.R. Garrod

Polyspecific antibodies were raised against vegetative cells of Dictyostelium discoideum, strain Ax2. Monovalent (Fab') fragments of antibodies CMC 1, 5, 7 and 12 blocked completely the cohesion of vegetative cells. Antibody CMC 1 was studied in detail. The Fab' of this blocked the cohesion of aggregation-competent cells by 40%. It also caused some loss of cell contact in aggregation streams. In so doing the contacts that remained were mostly at the ends of the cells. Immunofluorescence showed that CMC 1 Fab' bound to both the cytoplasm and the surface of fixed cells. It also bound to the surface of live cells. A control (N Fab') also bound to the cell surface but did not block vegetative cell cohesion. An extract of vegetative cells was obtained using the detergent Triton X-100. D. discoideum proteins were immunoprecipitated from this extract using protein A-Sepharose and CMC 1 immunoglobulin G (IgG). These immobilized proteins absorbed the cohesion-blocking activity of CMC 1 Fab'. About 30 proteins were obtained when the Triton-soluble fraction was immunoprecipitated with IgG of CMC 1, 5, 7 and 12. Five of these were found to be cell surface proteins by the technique of lactoperoxidase-catalysed radio-iodination. These proteins had molecular weights of 178 000, 166 000, 126 000 and 64 000. CMC 12 IgG immunoprecipitated an additional cell surface protein of 46 000 molecular weight. Slices of polyacrylamide gel containing each of the five proteins identified as possible contact sites were fixed, washed and incubated with CMC 1 Fab'. Gel that contained protein of 178 000, 166 000 and 64 000 molecular weight had no effect on the activity of CMC 1 Fab'. However, Fab' that had been incubated with gel containing protein of 126 000 molecular weight no longer blocked cell cohesion.


Author(s):  
Hiroshi Ueda ◽  
Yümi Maeda ◽  
Jun Kazami ◽  
Genji Kawano ◽  
Teruyuki Nagamune ◽  
...  

Author(s):  
K. Chien ◽  
I.P. Shintaku ◽  
A.F. Sassoon ◽  
R.L. Van de Velde ◽  
R. Heusser

Identification of cellular phenotype by cell surface antigens in conjunction with ultrastructural analysis of cellular morphology can be a useful tool in the study of biologic processes as well as in diagnostic histopathology. In this abstract, we describe a simple pre-embedding, protein A-gold staining method which is designed for cell suspensions combining the handling convenience of slide-mounted cell monolayers and the ability to evaluate specimen staining specificity prior to EM embedding.


2020 ◽  
Vol 36 (11) ◽  
pp. 3447-3456 ◽  
Author(s):  
Matthew Waas ◽  
Shana T Snarrenberg ◽  
Jack Littrell ◽  
Rachel A Jones Lipinski ◽  
Polly A Hansen ◽  
...  

Abstract Motivation Cell-type-specific surface proteins can be exploited as valuable markers for a range of applications including immunophenotyping live cells, targeted drug delivery and in vivo imaging. Despite their utility and relevance, the unique combination of molecules present at the cell surface are not yet described for most cell types. A significant challenge in analyzing ‘omic’ discovery datasets is the selection of candidate markers that are most applicable for downstream applications. Results Here, we developed GenieScore, a prioritization metric that integrates a consensus-based prediction of cell surface localization with user-input data to rank-order candidate cell-type-specific surface markers. In this report, we demonstrate the utility of GenieScore for analyzing human and rodent data from proteomic and transcriptomic experiments in the areas of cancer, stem cell and islet biology. We also demonstrate that permutations of GenieScore, termed IsoGenieScore and OmniGenieScore, can efficiently prioritize co-expressed and intracellular cell-type-specific markers, respectively. Availability and implementation Calculation of GenieScores and lookup of SPC scores is made freely accessible via the SurfaceGenie web application: www.cellsurfer.net/surfacegenie. Contact [email protected] Supplementary information Supplementary data are available at Bioinformatics online.


2007 ◽  
Vol 179 (5) ◽  
pp. 1067-1082 ◽  
Author(s):  
Valeria R. Caiolfa ◽  
Moreno Zamai ◽  
Gabriele Malengo ◽  
Annapaola Andolfo ◽  
Chris D. Madsen ◽  
...  

To search for functional links between glycosylphosphatidylinositol (GPI) protein monomer–oligomer exchange and membrane dynamics and confinement, we studied urokinase plasminogen activator (uPA) receptor (uPAR), a GPI receptor involved in the regulation of cell adhesion, migration, and proliferation. Using a functionally active fluorescent protein–uPAR in live cells, we analyzed the effect that extracellular matrix proteins and uPAR ligands have on uPAR dynamics and dimerization at the cell membrane. Vitronectin directs the recruitment of dimers and slows down the diffusion of the receptors at the basal membrane. The commitment to uPA–plasminogen activator inhibitor type 1–mediated endocytosis and recycling modifies uPAR diffusion and induces an exchange between uPAR monomers and dimers. This exchange is fully reversible. The data demonstrate that cell surface protein assemblies are important in regulating the dynamics and localization of uPAR at the cell membrane and the exchange of monomers and dimers. These results also provide a strong rationale for dynamic studies of GPI-anchored molecules in live cells at steady state and in the absence of cross-linker/clustering agents.


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