RayBio® Human c-Fos Transcription Factor Activity Assay. This assay uses a dsDNA coated plate with canonical c-Fos binding sequences to semi-quantitatively detect active c-Fos in lysates or nuclear extracts. Dry ice shipment (additional fee).
Activator protein-1 (AP-1) is a sequence-specific transcriptional activator composed of members of the Jun (c-Jun, JunB, and JunD) and Fos (c-FOS, FosB, Fra1, and Fra2) families in formats of homo- and heterodimers. These proteins belong to the bZIP group of DNA binding proteins with the ability to a common consensus sequence-defined AP-1-binding site. Jun and Fos proteins can also dimerize other basic leucine zipper proteins such as ATF, CCAAT enhancer-binding protein, Maf, and NF-E2. Jun-Jun and Jun-Fos dimers bind preferentially to the TPA responsive element (TRE), whose consensus is TGAGTCA, whereas Jun-ATF dimers prefer to bind to the c-AMP-responsive element (CRE), whose consensus is TGAGCTCA. Inside cells, AP-1 activity is induced by an incredible diversity of signals, including growth factors, cellular stress, ionizing and ultraviolet irradiation, DNA damage, oxidative stress, neuronal depolarization antigen binding by T or B lymphocytes, and cytokines. The mechanisms involved in the induction of AP-1 activity are either through changing the expression of AP-1 components or post-translation modification or both to regulate their trans-activity positively or negatively. For example, stimulation by growth factors or by activating mutations in cytoplasmic effectors such as ras and raf, results in AP-1 activation by triggering the ERK signaling pathway. On the other hand, AP-1 responses to proinflammatory cytokines and UV radiation are mostly dependent on two other MAPK cascades, JNK and p38 of MAP kinases. As a result, the AP-1 regulates different target genes executing different biological functions such as cell proliferation, differentiation, apoptosis, or cell death.
Product Features
Specific transcription factor-DNA binding assay
Perfect alternative to EMSA
Easy to perform in an ELISA format
Non-radioactive assay
High throughput (96-well plate format)
Assay can be completed within 5 hours
Application Notes
Kit Components
96-well Strip Microplate pre-coated with DNA probes
DNA Binding Buffer
Positive Control Sample
Specific Competitor DNA probe
Non-specific Competitor DNA probe
Assay Reagent
DTT
Wash Buffer
Primary Antibody
HRP-conjugated Secondary Antibody
Antibody Diluent Buffer
TMB One-Step Substrate Reagent
Stop Solution
Other Materials Required
Distilled or deionized water
100 ml and 1 liter graduated cylinders
Tubes to prepare sample dilutions
Absorbent paper
Precision pipettes to deliver 2 µl to 1 ml volumes
Adjustable 1-25 ml pipettes for reagent preparation
<lIκBenchtop rocker or shaker
Microplate reader capable of measuring absorbance at 450 nm
Protocol Outline
Prepare all reagents and samples as instructed in the manual.
Add 100 µl of sample or positive control to each well.
Incubate 2 h at RT or O/N at 4 °C.
Add 100 µl of prepared primary antibody to each well.
Incubate 1 h at RT.
Add 100 µl of prepared HRP-secondary antibody to each well.
Incubate 1 h at RT.
Add 100 µl of TMB One-Step Substrate Reagent to each well.
Incubate 30 min at RT.
Add 50 µl of Stop Solution to each well.
Read at 450 nm immediately.
Typical Data
Figure 1 Transcription factor assay of c-FOS from nuclear extracts of K562 cells or K562 cells treated with PMA (50 ng/ml) for 3 hr. A. Western-blot result of c-FOS from cytoplasmic and nuclear fractions. B. Transcription factor assay of c-FOS from nuclear fractions with the RayBio® Activity Assay Kit.
Figure 2 Transcription factor assay of c-FOS from nuclear extracts of K562 cells or K562 cells treated with PMA (50 ng/ml) for 3 hr with the specific competitor or non-specific competitor. The result shows specific binding of c-FOS to the conserved binding site detected by using the RayBio® c-FOS TF Activity Assay Kit.
Storage/Stability
Upon receipt, the positive control should be removed and stored at -20° or -80°C. The remainder of the kit can be stored for up to 6 months at 2-8°C from the date of shipment. Opened Microplate Wells or reagents may be stored for up to 1 month at 2° to 8°C. Return unused wells to the pouch containing desiccant pack, reseal along entire edge. Note: The kit can be used within one year if the whole kit is stored at -20°C upon receipt. Avoid repeated freeze-thaw cycles.
