Invitrogen™ Phospho-STAT4 (Tyr693) Monoclonal Antibody (4LURPIE), APC, eBioscience™, Invitrogen™

Catalog No.	Quantity
50-112-3211	100 Tests
50-112-3210	25 Tests

Catalog No. 50-112-3211 Supplier Invitrogen™ Supplier No. 17904442

Description

Mouse Monoclonal Antibody

Description: This 4LURPIE monoclonal antibody recognizes human and mouse signal transducer and activator of transcription 4 (STAT4) when phosphorylated on tyrosine 693 (Y693). STAT proteins are activated by ligand binding to cytokine receptors that associate with Janus kinase (JAK) family members. Following their phosphorylation by JAK proteins, STAT proteins translocate to the nucleus where they bind to DNA and regulate transcription of specific genes in a cell type- and cytokine-specific manner. STAT4 is activated by IL-12 or type 1 IFN (IFN alpha, IFN beta). STAT4 is required for optimal Th1 differentiation in vivo. Interestingly, although IFN alpha can lead to phosphorylation of STAT4 in mouse T cells, the phosphorylation is much weaker than that induced by IL-12 and is transient. Thus, IFN alpha phosphorylation of STAT4 does not contribute to STAT4-mediated Th1 development or IFN gamma production by Th1 cells in mice. In contrast, IFN alpha does promote Th1 development and function of human CD4+ T cells. Specificity of this 4LURPIE clone was determined by ELISA and flow cytometry. Applications Reported: This 4LURPIE antibody has been reported for use in intracellular staining followed by flow cytometric analysis. Applications Tested: This 4LURPIE antibody has been pre-titrated and tested by intracellular staining followed by flow cytometric analysis of stimulated normal human peripheral blood cells. This can be used at 5 μL (0.25 μg) per test.

STAT4 was originally identified using degenerate primers complementary to sequences encoding conserved regions of other STAT proteins. The STAT4 protein is most similar to STAT1 (52%) and STAT3 (47%). Functionally, STAT4 is similar to other STAT family members in that it can be tyrosine phosphorylated by Jak1 or Jak2. STAT4 forms homodimers and heterodimers with related STAT family members. Tyrosine phosphorylated STAT4 can bind the IFN-gamma activated site (GAS). Serine phosphorylation of STAT is also required for maximal transcriptional activity. STAT4 expression is restricted to the thymus, spleen and testis. Until recently the cytokine(s) responsible for activation of STAT4 had not been identified. STAT4 is now known to be activated by the cytokine interleukin 12 (IL-12). IL-12 is required for the T-cell independent induction of IFN-gamma which is a key step in the initial suppression of bacterial and parasitic infections. In addition, IL-12 is required for the development of a Th1 response which is necessary for effective host defense against intracellular pathogens. STAT4-deficient mice display impaired IL-12 development of Th1 cells and enhanced development of Th2 cells. A recent study in mouse has shown that in response to viral infection IFN-a/b activation of STAT4 is required for IFN-g production.

Specifications

• Antigen: Phospho-STAT4 (Tyr693)
• Applications: Flow Cytometry
• Classification: Monoclonal
• Clone: 4LURPIE
• Concentration: 5 μL/Test
• Conjugate: APC
• Formulation: PBS with BSA and 0.09% sodium azide; pH 7.2
• Gene: STAT4
• Gene Accession No.: P42228, Q14765
• Gene Alias: CIS4; HSPC060; OTTHUMP00000163553; Signal transducer and activator of transcription 4; SLEB11; SOCS4; SOCS6; SSI4; STAI4; STAT; Stat4; STATI4
• Gene Symbols: STAT4
• Host Species: Mouse
• Purification Method: Affinity chromatography
• Quantity: 100 Tests
• Regulatory Status: RUO
• Primary or Secondary: Primary
• Gene ID (Entrez): 20849, 6775
• Target Species: Human, Mouse
• Content And Storage: 4°C, store in dark, DO NOT FREEZE!
• Product Type: Antibody
• Form: Liquid
• Isotype: IgG1 κ

Frequently Asked Questions (FAQs)

How does eBioscience determine the specificity of their phosphorylation-specific antibodies?

Antibodies are tested and validated in a variety of ways. First, we verify that in a panel of cells in which different pathways have been induced, we see phosphorylation specific staining only in the cells in which the specific pathway of interest has been activated. Second, we verify that phosphorylation specific staining is observed only in cell types in which the protein is expressed and not in cell types in which the protein is not expressed. Third, whenever possible, western immunoblotting is used to confirm the presence of a band(s) of the appropriate size(s) in stimulated/treated cells (and not in unstimulated/untreated cells, as appropriate).

How long can cells that have been fixed and placed in methanol be stored for use with eBioscience antibodies? What is the recommended storage temperature? How about storage of fixed cells in eBioscience fixation buffers?

We have data demonstrating that fixed cells stored in methanol are stable at -20 degrees C or at -80 degrees C for several weeks. We do not recommend storing fixed cells in eBioscience Foxp3/Transcription Factor Buffer. However, cells fixed with eBioscience Foxp3/Transcription Factor Buffer or eBioscience Intracellular (IC) fixation buffer can be stored in eBioscience IC fixation buffer for up to 3 days at 4 degrees C in the dark.
Note: Please be aware that higher compensation values may be seen with tandem dyes if any other fixative is used apart from eBioscience IC fixation buffer, for 3-day storage.

What is the optimal protocol for eBioscience phosphorylation-specific antibodies?

Each antibody has been tested in three different buffer systems: IC fixation and permeabilization, Foxp3/Transcription Factor Buffer, and IC fixation Buffer/Methanol. The recommended buffer system(s) will be noted on the Technical Data Sheet for the specific antibody.

What is the best way to maintain surface staining when using the methanol-based protocol?

Because methanol can destroy the epitope recognized by some antibodies, ideally surface staining would be performed at the beginning of the protocol with a methanol-resistant fluorochrome (like eFluor 450, FITC, and eFluor 660).
Please recognize that surface staining before stimulation can have undesired effects due to activation of the cell caused by antibody binding. We recommend staining after stimulation/treatment, fixation, and methanol treatment.

Can I use other buffer systems from other companies when using eBioscience phosphorylation-specific antibodies?

In general, you can use other companies' buffer systems provided that their buffers are of a similar composition as the buffers recommended. Be aware that results will vary depending upon the buffer system used. eBioscience antibodies have been optimized for use in eBioscience buffers and we have not tested all of our antibodies in other buffer systems. Thus, we highly recommend using our optimized protocol and buffer systems.

What are the appropriate controls to run when using eBioscience phosphorylation-specific antibodies?

It is important to understand whether the stimulation/treatment results in an upregulation or a down regulation of the phosphorylation event. Thus, it is recommended that changes in phosphorylation levels in stimulated/treated versus unstimulated/untreated cells be compared. A histogram or density plot overlay these two treatments will provide a better assessment of a change in phosphorylation event than using isotype controls.

Can I perform phosphorylation specific staining and stain for intracellular cytokines at the same time when using eBioscience phosphorylation-specific antibodies?

In theory, if the buffer systems are compatible for the antibodies of interest, this can be done. In practice, cytokine translation and phosphorylation events do not typically occur in the same timeframe, therefore, it may be difficult to detect both events in the same sample. The results will be depended on the kinetics and should be determined for each system and protein of interest.

When using eBioscience phosphorylation-specific antibodies, can I perform phosphorylation specific staining together with transcription factor staining at the same time? If so, what buffer and protocol do I use?

In theory, this can be done if the antibodies against both the transcription factor and the phosphorylated protein work in the same buffer system. For example, Anti-Human/Mouse phsopho-H2AX and all transcription factor eBioscience antibodies offered will work in the Foxp3/Transcription Factor Buffer System (Cat. No. 00-5523-00).

For eBioscience phosphorylation-specific antibodies, can total and phosphorylated protein be analyzed in parallel?

In theory, this can be done if the antibodies to both proteins work in the same buffer system and if the antibodies recognize different epitopes. Please refer to the individual Technical Data Sheets for information about buffer compatibility. Also, consider using eBioscience InstantOne ELISA Kits for immunoassay quantitation of both total and phosphorylated proteins such as AKT1/2/3, JNK1/2/3, NFκB, STAT3, and STAT5.

Safety and Handling

WARNING: Reproductive Harm - www.P65Warnings.ca.gov

For Research Use Only.