The Tango assay is a specialized laboratory technique used to understand how cells communicate. As a cell-based assay, it utilizes living cells to observe biological processes. This assay studies cell signaling, the process by which cells receive and respond to environmental messages, playing a role in many bodily functions.
Understanding G Protein-Coupled Receptors
Understanding the Tango assay requires knowledge of G protein-coupled receptors (GPCRs). These cell surface proteins act like molecular antennae, receiving signals like hormones, neurotransmitters, or light from outside the cell.
Upon signaling, GPCRs change shape, initiating intracellular events. This internal signaling affects cellular activities, from regulating mood and pain to controlling heart rate and digestion. Due to their widespread involvement in bodily functions, GPCRs are frequent targets for drug development.
How the Tango Assay Works
The Tango assay measures the interaction between an activated GPCR and beta-arrestin. The GPCR is engineered with a protease cleavage site and a transcription factor on its intracellular tail. Beta-arrestin is fused to a protease enzyme.
When a signal activates the GPCR, beta-arrestin is recruited to the receptor. This recruitment brings the protease to the GPCR’s cleavage site, cutting the transcription factor. The released transcription factor moves to the cell’s nucleus, activating a reporter gene. This activation produces a measurable signal (often fluorescent or luminescent), indicating GPCR activation.
Applications in Drug Discovery
The Tango assay is widely used in pharmaceutical research for screening potential drug candidates. It allows efficient testing of large numbers of compounds for GPCR interaction. This high-throughput screening identifies new molecules that can activate (agonists) or block (antagonists) specific GPCRs, potentially leading to new medications.
For instance, the assay aids in discovering drugs for conditions like pain, inflammation, and neurological disorders, as many existing medications target GPCRs. By observing how compounds affect GPCR activation, researchers can pinpoint promising drug leads to modulate these receptors for therapeutic benefit. The assay also assesses the relative effectiveness of compounds.
Advantages of the Tango Assay
The Tango assay offers several benefits for drug discovery research. Its high-throughput capability allows for rapid testing of vast numbers of compounds, accelerating early drug development. The assay is also highly sensitive, detecting even subtle interactions between compounds and GPCRs.
The Tango assay specifically measures beta-arrestin recruitment, a GPCR signaling pathway distinct from traditional G protein activation. This offers insights into functional selectivity (biased agonism), leading to drugs with more targeted effects and potentially fewer side effects.