Description
Key facts
Detection method:Colorimetric,
Sample types:Nuclear Extracts,
Reacts with:Mouse, Rat, Human,
Assay type:Semi-quantitative,
Sensitivity:< 1250 ng/mL,
Assay time:3h 30m,
Assay Platform:Microplate reader
Product details:
Fos B Transcription Factor Assay Kit (Colorimetric) (ab207197) is a high throughput assay to quantify AP-1 Fos B activation in nuclear extracts. This assay combines a quick ELISA format with a sensitive and specific non-radioactive assay for transcription factor activation
A specific double stranded DNA sequence containing the TPA-responsive element (TRE) (5´ - TGAGTCA - 3´) has been immobilized onto a 96-well plate. AP1 present in the nuclear extract specifically binds to the oligonucleotide. AP1 family member Fos B is detected by a primary antibody that recognizes an epitope of Fos B accessible only when the protein is activated and bound to its target DNA. An HRP-conjugated secondary antibody provides sensitive colorimetric readout at OD 450 nm. This product detects human, mouse and rat Fos B.
Key performance and benefits:
Assay time: 3.5 hours (cell extracts preparation not included).
Detection limit: < 1.25 μg nuclear extract/well.
Detection range: 0.1 – 20 μg nuclear extract/well.
The activator protein-1 (AP1) transcription factors belong to a large family of structurally related transcription factors that includes ATF1-4, c-Fos, c-Jun, c-Myc and C/EBP. The members of this family, named bZIP, share a dimerization domain with a leucine zipper motif and a DNA binding domain rich in basic residues (lysines and arginines). AP1 is composed of a mixture of heterodimeric complexes of proteins derived from the Fos and Jun families including c- Fos, FosB, Fra-1, Fra-2, c-Jun, JunB and JunD. Only Jun proteins can form transcriptionally active homodimers within AP1 members, or heterodimers with CREB/ATF members, to bind the CRE element (5´ - TGACGTCA - 3´). Primarily, AP1 dimers bind to DNA on a TPA-response element (TRE) with the 5´ - TGA(C/G)TCA - 3´ sequence. Jun-Fos heterodimers form more stable complexes with TREs. These complexes display stronger transactivating activity than Jun-Jun homodimers.
Phosphorylation of AP1 family members by kinases is required for transactivation activity. For the Fos proteins, both N- and C-terminal domains flanking the bZIP domain require phosphorylation for biological activity.
AP1 expression is induced by multiple stimuli such as serum, growth factors, phorbol esters and oncogenes. These include peptide growth factors, cytokines of the TGF beta, TNF, and interferon families, neuronal depolarization and cellular stress. Upon serum starvation of human fibroblast cells, Fos and Jun protein production can be induced for up to 4 hours by adding serum. Interestingly, serum starvation lowers basal expression of FosB and c-Fos but has no significant effect on c-Jun.
AP1 proteins play a role in the expression of many genes involved in proliferation and cell cycle progression including neuronal apoptosis, learning process, drug-induced behavorial responses, bone growth and differentiation, and embryo development. For instance, cell transformation by oncogenes that function in the growth factor signal transduction pathway, such as
, results in a high increase in AP1 component protein expression. Therefore, AP1-regulated genes support the invasive process observed during malignancy and metastasis.
Properties and Storage Information:
Shipped at conditions-Dry Ice, Appropriate short-term storage conditions-Multi, Appropriate long-term storage conditions-Multi, Storage information-Please refer to protocols
Supplementary Information:
This supplementary information is collated from multiple sources and compiled automatically.
Fos B also known as FosB is a protein encoded by the FOSB gene and belongs to the Fos family of transcription factors. Weighing approximately 46 kDa this protein acts within the cell nucleus and is expressed in several tissues particularly in brain regions. Delta Fos B an isoform of Fos B has gained attention for its stable accumulation in certain neuronal populations. Researchers often study Fos B using techniques like ELISA and immunohistochemistry to investigate its presence and distribution.
Biological function summary
Functions of Fos B include regulation of gene expression through forming AP-1 transcription factor complexes with Jun family proteins. These complexes bind to DNA influencing the expression of genes involved in processes such as cell proliferation differentiation and survival. Fos B is structurally similar to other Fos family proteins such as c-Fos which emphasises its role in response to extracellular signals and stress stimuli. Both Fos B and its isoform Delta Fos B have distinct expression patterns suggesting unique functions.
Pathways
Fos B plays a role in the MAPK/ERK signaling pathway which is essential for transmitting extracellular signals to promote diverse cellular responses. Within this pathway interactions with proteins like Jun lead to modulation of gene expression critical for cellular responses to growth factors. Additionally connections to the CREB signaling pathway link Fos B to processes concerning neuronal plasticity and memory further highlighting its participation in important biological functions.
Involvement of Fos B has been noted in neurological conditions such as addiction and depression. Delta Fos B in particular accumulates in response to chronic drug exposure and serves as a molecular switch in addiction-related neuroadaptations. Connections with proteins such as CREB and other transcriptional regulators have broadened the understanding of how Fos B and its isoforms impact neural circuits and contribute to the pathology of mood disorders.
