GAL4 Reporter Lentivirus

Background

GAL4 is a transcription factor from yeast that binds a defined DNA sequence called the upstream activating sequence (UAS). Because mammalian cells lack endogenous GAL4 and UAS elements, the GAL4-UAS system functions as an orthogonal, low-background transcriptional switch and is a foundational tool in molecular biology. In the mammalian two-hybrid assay, a protein of interest is fused to the GAL4 DNA-binding domain and a candidate partner is fused to the VP16 activation domain; only if the two proteins interact is the activation domain recruited to the UAS, switching on reporter expression. This design provides a sensitive, quantitative readout of protein-protein interactions in living cells.

Product Description & Applications

The GAL4 Reporter Lentivirus is a lentiviral reporter system for the rapid readout of protein-protein interactions, suitable for mammalian two-hybrid assays. The construct contains five tandem repeats of the GAL4 UAS upstream of a fluorescent (GFP or RFP) or luminescent reporter, allowing convenient detection by fluorescence microscopy, flow cytometry, or luminometry. Reporter activity is produced in response to a GAL4 DNA-binding-domain fusion protein and is strongly enhanced when an interacting VP16 activation-domain fusion is present. Antibiotic selection markers (puromycin or blasticidin) support establishment of stable reporter cell lines. The system is used to detect and quantify protein-protein interactions and to screen interaction modulators. Supplied as lentiviral particles purified by PEG precipitation and sucrose gradient centrifugation, it efficiently transduces difficult-to-transfect cells, including primary and thawed cells.

About This Product

This reporter lentivirus places a EGFP, Firefly Luc, GFP + Firefly Luc, mCherry, Renilla Luc, GFP, RFP, Luc reporter gene under the control of tandem consensus response elements specific for the GAL4-DBD for PPI and two-hybrid assay transcription factor, coupled to a minimal TATA-box promoter and a proprietary upstream enhancer that maximizes signal-to-noise. The constitutively expressed selection marker (Puromycin, Blasticidin) and/or secondary reporter enables stable polyclonal cell line generation and flexible readout by fluorescence microscopy, flow cytometry, or luminometry.

Stable integration via the lentiviral backbone ensures consistent, clonally representative reporter expression in dividing and post-mitotic target cells — including primary T cells, macrophages, organoids, and cryopreserved material — eliminating the variability inherent to transient transfection. The self-inactivating LTR design and third-generation packaging minimize insertional mutagenesis risk and ensure biosafety classification at BSL-2.