Vitamin D Receptor (VDR; NR1I1)
|Product Family||Product Number||Product Description||Technical Manual|
|IB00701-32||Human VDR Reporter Assay System, 3 x 32 assays in 96-well format||Technical Manual|
|IB00701||Human VDR Reporter Assay System, 1 x 96-well format assays||Technical Manual|
|IB00702||Human VDR Reporter Assay System, 1 x 384-well format assays||Technical Manual|
Vitamin D Receptor Assay Kit
This Vitamin D Receptor (VDR) assay kit is an all-inclusive firefly luciferase reporter assay system that includes, in addition to VDR Reporter Cells, two optimized media for use during cell culture and (optionally) in diluting the test samples, a reference agonist, Luciferase Detection Reagent, a cell culture-ready assay plate, and a detailed protocol.
VDR Reporter Cells are prepared using INDIGO’s proprietary CryoMite™ process. This cryo-preservation method yields high cell viability post-thaw, and provides the convenience of immediately dispensing healthy, division-competent reporter cells into assay plates. There is no need for intermediate spin-and-wash steps, viability determinations, or cell titer adjustments prior to assay setup.
INDIGO’s VDR assay kits feature a luciferase detection reagent specially formulated to provide stable light emission between 5 and 90+ minutes after initiating the luciferase reaction. Incorporating a 5-minute reaction-rest period ensures that light emission profiles attain maximal stability, thereby allowing assay plates to be processed in batch. By doing so, the signal output from all sample wells, from one plate to the next, may be directly compared within an experimental set.
Vitamin D Receptor reporter assay kits are offered in different assay formats to accommodate researchers’ needs: 3x 32, 1x 96, and 1x 384 assay formats for screening small numbers of test compounds, as well as custom bulk reagents for HTS applications.
Bulk assay reagents can be custom manufactured to accommodate any scale of HTS. Please inquire.
Vitamin D Receptor Assay Services
The primary application of INDIGO’s cell-based nuclear receptor assays are to quantitatively assess the bioactivity of a test compound as an agonist (activator) or antagonist (inhibition of an agonist response) of a given receptor. Service assays include a positive control reference compound and ‘vehicle’ control for every experiment. A formal study report and all data files are provided to the client upon completion of the study. To receive a quote for your proposed study, complete & submit the online “Request a Quote” form or contact an INDIGO Customer Service Representative to discuss your desired study parameters.
Vitamin D Receptor Background
INDIGO’s Human Vitamin D Receptor Assay utilizes proprietary Human cells engineered to provide high-level expression of Human VDR (also known as NR1I1). Reporter Cells also incorporate a luciferase reporter gene. Quantifying expressed luciferase activity at the assay endpoint provides a sensitive surrogate measure of changes in VDR activity in treated cells. The principle application of this reporter assay system is in the screening of test samples to quantify functional activity, either agonist or antagonist, that may exert against the Human VDR.
The calcitriol receptor, also known as the vitamin D receptor (VDR) is a member of the nuclear receptor family of transcription factors. Upon activation by vitamin D, the VDR forms a heterodimer with the retinoid-X receptor and binds to hormone response elements on DNA resulting in expression or transrepression of specific gene products. Glucocorticoids are known to decrease expression of VDR which is expressed in most tissues of the body and regulate intestinal transport of calcium. This gene encodes the nuclear hormone receptor for vitamin D3. This receptor also functions as a receptor for the secondary bile acid lithocholic acid. The receptor belongs to the family of trans-acting transcriptional regulatory factors and shows similarity of sequence to the steroid and thyroid hormone receptors. Downstream targets of this nuclear hormone receptor are principally involved in mineral metabolism though the receptor regulates a variety of other metabolic pathways, such as those involved in the immune response and cancer. Mutations in this gene are associated with type II vitamin D-resistant rickets. A single nucleotide polymorphism in the initiation codon results in an alternate translation start site three codons downstream. Alternative splicing results in multiple transcript variants encoding the same protein.
For more information on VDR, visit the Nuclear Receptor Resource.
Synonyms: Vitamin D Receptor, VDR, Human Vitamin D Receptor, hVDR, Human VDR, 1,25-Dihydroxyvitamin D3 Receptor, NR1I1
Vitamin D Receptor Assay Data
Agonist dose-response analyses of Human VDR. Agonist analyses of VDR Reporter Cells using Calcitriol (provided), Calcipotriol (Cayman Chemical), Ercalcitriol, EB1089, and Doxercalciferol (each from Tocris). In addition, to assess the level of background signal contributed by non-specific factors that may cause activation of the luciferase reporter gene, “mock” reporter cells were treated with calcitriol (mock reporter cells, which contain only the luciferase vector, are not provided with assay kits). Final assay concentrations for ligand-treated cells ranged from 10,000 nM to 38 pM for Doxercalciferol, and 800 nM to 50 pM for all others. Luminescence was quantified using a GloMax-Multi+ luminometer (Promega). Average relative light units (RLU) and corresponding standard deviation (SD) values were determined for each treatment concentration (n ≥ 6). Fold-activation and Z’ values were calculated as described by Zhang, et al. (1999). Non-linear regression and EC50 analyses were performed using GraphPad Prism software. Mock reporter cells demonstrate no significant background luminescence (< 0.02% that of the reporter cells at ECMax of calcitriol). Thus, luminescence results strictly through ligand-activation of VDR expressed in these reporter cells. High Z' scores confirm the robust performance of this assay, and it's suitability for HTS.