A novel 4-amino-1,8-naphthalimide (NDI) with two different metal cation receptors connected at 4-amino or imide nitrogen positions respectively was designed and prepared. Significant internal charge transfer (ICT) as well as photoinduced electron transfer (PET) from the receptors to NDI is revealed by the shifted UV-vis absorption spectra and significant fluorescence quenching. Both Zn(2+) and ...

The membrane-localized proteins Linker for Activation of T cells (LAT), Growth Factor Receptor-Bound Protein 2 (Grb2), and Son Sevenless (SOS) exhibit protein condensation phase transitions in vitro vivo. These condensates play a critical role antigen discrimination by cell receptor (TCR). While there are some similarities between the LAT:Grb2:SOS intracellular droplets formed liquid-liquid sep...

We report a highly specific fluorescence lifetime imaging microscopy (FLIM) method for monitoring epidermal growth factor receptor (EGFR) phosphorylation in cells based on fluorescence resonance energy transfer (FRET). EGFR phosphorylation was monitored using a green fluorescent protein (GFP)-tagged EGFR and Cy3-conjugated anti-phosphotyrosine antibodies. In this FRET-based imaging method, the ...

Despite the widely accepted assumption that most endosomal compartments are acidic, evaluation of the efficiency of pH-dependent drug release from a ligand-targeted drug conjugate during receptor-mediated endocytosis is lacking. Therefore, we have characterized the kinetics of pH-dependent drug release from a model folate-drug conjugate during folate receptor (FR)-mediated endosomal trafficking...

The association between nuclear distribution and mobility of the human glucocorticoid receptor was examined in living COS-1 cells using yellow fluorescent protein- and cyan fluorescent protein-tagged receptors. Quantitation of the nuclear distribution induced by an array of glucocorticoid ligands revealed a continuum from a random (cortisone) to a nonrandom (triamcinolone acetonide) receptor di...

Novel bi-chromophoric naphthalimide derivatives containing benzo-15-crown-5 and N-phenyl-aza-15-crown-5 receptor moieties BNI2 and BNI3 were designed and prepared. Significant Förster resonance energy transfer (FRET) from donor (D) amido-naphthalimide to acceptor (A) amino-naphthalimide chromophores as well as photoinduced electron transfer (PET) between the N-aryl receptor and amido-naphthalim...

Mu-opioid receptor (MOR) signaling regulates multiple neuronal pathways, including those involved in pain, reward, and respiration. To advance the understanding of MOR's roles pain modulation, there is a need for high-throughput screening methods opioids vitro high-resolution mapping brain. fill this need, we designed characterized genetically encoded fluorescent reporter, called Single-chain P...

Receptor clustering is known to trigger signalling events that contribute to critical changes in cellular functions. Faithful imaging of such clusters by means of fluorescence microscopy relies on the application of adequate cell fixation methods prior to immunolabelling in order to avoid artefactual redistribution by the antibodies themselves. Previous work has highlighted the inadequacy of fi...

The N-terminal domain of chemokine receptors constitutes one of the two critical ligand binding sites, and plays important roles by mediating binding affinity, receptor selectivity, and regulating function. In this work, we monitored the organization and dynamics of a 34-mer peptide of the CXC chemokine receptor 1 (CXCR1) N-terminal domain and its interaction with membranes by utilizing a combi...

The fluorescent binding of tamoxifen to eosin is used on Papanicolaou-stained smears as a marker of cell responsiveness to the antiestrogen molecule. Forty-two cases of human breast carcinomas were submitted to tamoxifen treatment between first diagnosis and surgery (4 to 30 days). Tamoxifen-induced fluorescence is observed in 17 of 42 cases (40%). There is a highly significant correlation betw...