scholarly journals Cellular Dielectric Spectroscopy: A Powerful New Approach to Label-Free Cellular Analysis

2004 ◽  
Vol 9 (6) ◽  
pp. 467-480 ◽  
Author(s):  
Gary J. Ciambrone ◽  
Vivian F. Liu ◽  
Deborah C. Lin ◽  
Ryan P. McGuinness ◽  
Gordon K. Leung ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Dielectric Spectroscopy ◽  
Protein Tyrosine Kinase ◽  
Label Free ◽  
Biologically Relevant ◽  
Lead Compounds ◽  
Cellular Analysis ◽  
Cellular Signal ◽  
Receptor Signaling Pathway ◽  
Specific Frequency

The past decade has seen a number of significant changes in identifying higher quality lead compounds earlier in the drug discovery process. Cell-based assay technologies yielding high-content information have emerged to achieve this goal. Although most of these systems are based on fluorescence detection, this article describes the development and application of an innovative cellular assay technology based on radio frequency spectrometry and bioimpedance measurements. Using this technique, the authors have discovered a link between cellular bioimpedance changes and receptor-mediated signal transduction events. By performing dielectric spectroscopy of cells across as pectrum of frequencies (1 KHz to 110 MHz), a series of receptor-specific, frequency-dependent impedance patterns is collected. These raw data patterns are used to determine the identity of the cellular receptor-signaling pathway being tested and to quantify stimulation endpoints and kinetics. The authors describe the application of this technology to the analysis of ligand-induced cellular responses mediated by the 3 major classes of G-protein-coupled receptors (GPCRs) and protein tyrosine kinase receptors. This single assay platform can be used with ease to monitor Gs, Gi, and Gq GPCRs without the need for chimeric or promiscuous G-proteins, fluorophors, or tagged proteins. In contrast to other methods of monitoring cellular signal transduction, this approach provides high information content in a simplified, noninvasive, and biologically relevant fashion.

Synthesis of Drugs and Biorelevant N-heterocycles Employing Recent Advances in C-N Bond Formation

2020 ◽  
Vol 24 (20) ◽  
pp. 2293-2340
Author(s):  
Firdoos Ahmad Sofi ◽  
Prasad V. Bharatam
Keyword(s):  
Kinase Inhibitors ◽  
Bond Formation ◽  
Comprehensive Review ◽  
Biologically Relevant ◽  
Lead Compounds ◽  
Heterocyclic Molecules ◽  
The Past ◽  
Anti Cancer ◽  
Modern Methods ◽  
Bond Formation Reactions

C-N bond formation is a particularly important step in the generation of many biologically relevant heterocyclic molecules. Several methods have been reported for this purpose over the past few decades. Well-known named reactions like Ullmann-Goldberg coupling, Buchwald-Hartwig coupling and Chan-Lam coupling are associated with the C-N bond formation reactions. Several reviews covering this topic have already been published. However, no comprehensive review covering the synthesis of drugs/ lead compounds using the C-N bond formation reactions was reported. In this review, we cover many modern methods of the C-N bond formation reactions, with special emphasis on metal-free and green chemistry methods. We also report specific strategies adopted for the synthesis of drugs, which involve the C-N bond formation reactions. Examples include anti-cancer, antidepressant, anti-inflammatory, anti-atherosclerotic, anti-histaminic, antibiotics, antibacterial, anti-rheumatic, antiepileptic and anti-diabetic agents. Many recently developed lead compounds generated using the C-N bond formation reactions are also covered in this review. Examples include MAP kinase inhibitors, TRKs inhibitors, Polo-like Kinase inhibitors and MPS1 inhibitors.

scholarly journals A critical cytoplasmic domain of the interleukin-5 (IL-5) receptor alpha chain and its function in IL-5-mediated growth signal transduction.

1994 ◽  
Vol 14 (11) ◽  
pp. 7404-7413 ◽  
Author(s):  
S Takaki ◽  
H Kanazawa ◽  
M Shiiba ◽  
K Takatsu
Keyword(s):  
Signal Transduction ◽  
Protein Tyrosine Kinase ◽  
Cytoplasmic Domain ◽  
Beta Chain ◽  
Cytoplasmic Domains ◽  
Interleukin 5 ◽  
Alpha Chain ◽  
Gm Csf ◽  
Response Expression ◽  
And Function

Interleukin-5 (IL-5) regulates the production and function of B cells, eosinophils, and basophils. The IL-5 receptor (IL-5R) consists of two distinct membrane proteins, alpha and beta. The alpha chain (IL-5R alpha) is specific to IL-5. The beta chain is the common beta chain (beta c) of receptors for IL-3 and granulocyte-macrophage colony-stimulating factor (GM-CSF). The cytoplasmic domains of both alpha and beta chains are essential for signal transduction. In this study, we generated cDNAs of IL-5R alpha having various mutations in their cytoplasmic domains and examined the function of these mutants by expressing them in IL-3-dependent FDC-P1 cells. The membrane-proximal proline-rich sequence of the cytoplasmic domain of IL-5R alpha, which is conserved among the alpha chains of IL-5R, IL-3R, and GM-CSF receptor (GM-CSFR), was found to be essential for the IL-5-induced proliferative response, expression of nuclear proto-oncogenes such as c-jun, c-fos, and c-myc, and tyrosine phosphorylation of cellular proteins including JAK2 protein-tyrosine kinase. In addition, analysis using chimeric receptors which consist of the extracellular domain of IL-5R alpha and the cytoplasmic domain of beta c suggested that dimerization of the cytoplasmic domain of beta c may be an important step in activating the IL-5R complex and transducing intracellular growth signals.

Cellular Dielectric Spectroscopy: A Label-Free Technology for Drug Discovery

2005 ◽  
Vol 10 (4) ◽  
pp. 258-269 ◽  
Author(s):  
G LEUNG ◽  
H TANG ◽  
R MCGUINNESS ◽  
E VERDONK ◽  
J MICHELOTTI ◽  
...  
Keyword(s):  
Drug Discovery ◽  
Dielectric Spectroscopy ◽  
Label Free

scholarly journals Characterization of the Kaposi's Sarcoma-Associated Herpesvirus K1 Signalosome

2005 ◽  
Vol 79 (19) ◽  
pp. 12173-12184 ◽  
Author(s):  
Bok-Soo Lee ◽  
Sun-Hwa Lee ◽  
Pinghui Feng ◽  
Heesoon Chang ◽  
Nam-Hyuk Cho ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Inflammatory Cytokines ◽  
Kaposi's Sarcoma ◽  
Mutational Analysis ◽  
Tyrosine Phosphatase ◽  
Kaposi’S Sarcoma ◽  
Sh2 Domain ◽  
Signaling Proteins ◽  
Cellular Signal ◽  
Cellular Components

ABSTRACT Kaposi's sarcoma (KS) is a multifocal angiogenic tumor and appears to be a hyperplastic disorder caused, in part, by local production of inflammatory cytokines. The K1 lymphocyte receptor-like protein of KS-associated herpesvirus (KSHV) efficiently transduces extracellular signals to elicit cellular activation events through its cytoplasmic immunoreceptor tyrosine-based activation motif (ITAM). To further delineate K1-mediated signal transduction, we purified K1 signaling complexes and identified its cellular components. Upon stimulation, the K1 ITAM was efficiently tyrosine phosphorylated and subsequently interacted with cellular Src homology 2 (SH2)-containing signaling proteins Lyn, Syk, p85, PLCγ2, RasGAP, Vav, SH2 domain-containing protein tyrosine phosphatase 1/2, and Grab2 through its phosphorylated tyrosine residues. Mutational analysis demonstrated that each tyrosine residue of K1 ITAM contributed to the interactions with cellular signaling proteins in distinctive ways. Consequently, these interactions led to the marked augmentation of cellular signal transduction activity, evidenced by the increase of cellular tyrosine phosphorylation and intracellular calcium mobilization, the activation of NF-AT and AP-1 transcription factor activities, and the production of inflammatory cytokines. These results demonstrate that KSHV K1 effectively recruits a set of cellular SH2-containing signaling molecules to form the K1 signalosome, which elicits downstream signal transduction and induces inflammatory cytokine production.

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