Upconversion Nanophosphor: An Efficient Phosphopeptides-Recognizing Matrix and Luminescence Resonance Energy Transfer Donor for Robust Detection of Protein Kinase Activity

2014 ◽  
Vol 86 (12) ◽  
pp. 6095-6102 ◽  
Author(s):  
Chenghui Liu ◽  
Lijuan Chang ◽  
Honghong Wang ◽  
Jie Bai ◽  
Wei Ren ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Protein Kinase ◽  
Kinase Activity ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Protein Kinase Activity ◽  
Robust Detection ◽  
Upconversion Nanophosphor

scholarly journals Phospholemman Phosphorylation Alters Its Fluorescence Resonance Energy Transfer with the Na/K-ATPase Pump

2006 ◽  
Vol 281 (43) ◽  
pp. 32765-32773 ◽  
Author(s):  
Julie Bossuyt ◽  
Sanda Despa ◽  
Jody L. Martin ◽  
Donald M. Bers
Keyword(s):  
Protein Kinase C ◽  
Energy Transfer ◽  
Protein Kinase ◽  
Fluorescence Resonance Energy Transfer ◽  
Cardiac Myocyte ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Hek293 Cells ◽  
Kinase C ◽  
Fluorescence Resonance

Phospholemman (PLM) or FXYD1 is a major cardiac myocyte phosphorylation target upon adrenergic stimulation. Prior immunoprecipitation and functional studies suggest that phospholemman associates with the Na/K-pump (NKA) and mediates adrenergic Na/K-pump regulation. Here, we tested whether the NKA-PLM interaction is close enough to allow fluorescence resonance energy transfer (FRET) between cyan and yellow fluorescent (CFP/YFP) fusion proteins of Na/K pump and phospholemman and whether phospholemman phosphorylation alters such FRET. Co-expressed NKA-CFP and PLM-YFP in HEK293 cells co-localized in the plasma membrane and exhibited robust FRET. Selective acceptor photobleach increased donor fluorescence (FCFP) by 21.5 ± 4.1% (n = 13), an effect nearly abolished when co-expressing excess phospholemman lacking YFP. Activation of protein kinase C or A progressively and reversibly decreased FRET assessed by either the fluorescence ratio (FYFP/FCFP) or the enhancement of donor fluorescence after acceptor bleach. After protein kinase C activation, forskolin did not further reduce FRET, but after forskolin pretreatment, protein kinase C could still reduce FRET. This agreed with phospholemman phosphorylation measurements: by protein kinase C at both Ser-63 and Ser-68, but by protein kinase A only at Ser-68. Expression of PLM-YFP and PLM-CFP resulted in even stronger FRET than for NKA-PLM (FCFP increased by 37 ± 1% upon YFP photobleach), and this FRET was enhanced by phospholemman phosphorylation, consistent with phospholemman multimerization. Co-expressed PLM-CFP and Na/Ca exchange-YFP were highly membrane co-localized, but FRET was undetectable. We conclude that phospholemman and Na/K-pump are in very close proximity (FRET occurs) and that phospholemman phosphorylation alters the interaction of Na/K-pump and phospholemman.

scholarly journals A cGMP-Dependent Protein Kinase Assay for High Throughput Screening Based on Time-Resolved Fluorescence Resonance Energy Transfer

2001 ◽  
Vol 6 (4) ◽  
pp. 255-264 ◽  
Author(s):  
Benjamin Bader ◽  
Elke Butt ◽  
Alois Palmetshofer ◽  
Ulrich Walter ◽  
Thomas Jarchau ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Protein Kinase ◽  
Fluorescence Resonance Energy Transfer ◽  
High Throughput ◽  
Cyclic Gmp ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Dependent Protein Kinase ◽  
Time Resolved ◽  
Dependent Protein

Activation of cyclic GMP-dependent protein kinase (cGK) is an important event in the regulation of blood pressure and platelet function. Upstream signals are the generation of nitric oxide (NO) by NO syntheses and the subsequent rise in cyclic GMP levels mediated by NO-dependent guanylyl cyclases (GCs). The identification of new cGK activators by high throughput sreening (HTS) may lead to the development of a novel class of therapeutics for the treatment of cardiovascular diseases. Therefore, a homogeneous, nonradioactive assay for cGK activity was developed using a biotinylated peptide derived from vasodilator-stimulated phosphoprotein (VASP), a well-characterized natural cGK substrate. The phosphorylated peptide could be detected by a VASP-specific monoclonal phosphoserine antibody and a fluorescent detection system consisting of a europium-labeled secondary antibody and allophycocyanin (APC)-labeled streptavidin. Fluorescence resonance energy transfer (FRET) from europium to APC was detected in a time-resolved fashion (TR-FRET). Activation and inhibition constants for known substances determined by this new fluorescence-based assay correlated well with published results obtained by conventional radioactive cGK activity assays. The assay proved to be sensitive, robust, highly specific for cGK, and suitable for HTS in 96- and 384-well formats. This assay is applicable to purified enzymes as well as to complex samples such as human platelet extracts.

scholarly journals Stimulus-Specific Distinctions in Spatial and Temporal Dynamics of Stress-Activated Protein Kinase Kinase Kinases Revealed by a Fluorescence Resonance Energy Transfer Biosensor

2009 ◽  
Vol 29 (22) ◽  
pp. 6117-6127 ◽  
Author(s):  
Taichiro Tomida ◽  
Mutsuhiro Takekawa ◽  
Pauline O'Grady ◽  
Haruo Saito
Keyword(s):  
Energy Transfer ◽  
Protein Kinase ◽  
Fluorescence Resonance Energy Transfer ◽  
Cell Population ◽  
Temporal Dynamics ◽  
Single Cells ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
A Cell ◽  
Fluorescence Resonance

ABSTRACT The stress-activated protein kinases (SAPKs), namely, p38 and JNK, are members of the mitogen-activated protein kinase family and are important determinants of cell fate when cells are exposed to environmental stresses such as UV and osmostress. SAPKs are activated by SAPK kinases (SAP2Ks), which are in turn activated by various SAP2K kinases (SAP3Ks). Because conventional methods, such as immunoblotting using phospho-specific antibodies, measure the average activity of SAP3Ks in a cell population, the intracellular dynamics of SAP3K activity are largely unknown. Here, we developed a reporter of SAP3K activity toward the MKK6 SAP2K, based on fluorescence resonance energy transfer, that can uncover the dynamic behavior of SAP3K activation in cells. Using this reporter, we demonstrated that SAP3K activation occurs either synchronously or asynchronously among a cell population and in different cellular compartments in single cells, depending on the type of stress applied. In particular, SAP3Ks are activated by epidermal growth factor and osmostress on the plasma membrane, by anisomycin and UV in the cytoplasm, and by etoposide in the nucleus. These observations revealed previously unknown heterogeneity in SAPK responses and supplied answers to the question of the cellular location in which various stresses induce stimulus-specific SAPK responses.

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