Recombinant Human MAP2K4 Protein: Properties & Applications

Recombinant Human MAP2K4 Protein is a dual-specificity mitogen-activated protein kinase kinase that serves as a critical upstream activator of the JNK and p38 MAPK stress-response pathways, making it an essential reagent for dissecting cellular stress signaling in vitro.

Protein Name

Recombinant Human MAP2K4 (MKK4/SEK1/JNKK1)

Biological Function

Dual-specificity kinase; activates JNK and p38 MAPK by phosphorylating threonine and tyrosine residues

Pathway

MAPK/JNK stress-activated signaling cascade

Primary Applications

In vitro kinase assays, Western blot, ELISA, drug screening

Source

Recombinant human protein produced in an expression system

Catalog SKU

rp370115

Biological Background and Signaling Role of MAP2K4

MAP2K4 (Mitogen-Activated Protein Kinase Kinase 4), also known as MKK4, SEK1, and JNKK1, is a member of the MAP2K family of dual-specificity protein kinases. It functions as a direct upstream activator within the stress-activated MAPK cascades, most prominently the c-Jun N-terminal kinase (JNK) and p38 MAPK pathways.

Upon exposure to environmental stressors such as UV irradiation, osmotic shock, inflammatory cytokines, and oxidative stress, MAP2K4 is phosphorylated and activated by upstream MAP3Ks including ASK1, MEKK1, and TAK1. Once activated, MAP2K4 phosphorylates JNK on Thr183/Tyr185 and p38 MAPK on Thr180/Tyr182, triggering downstream transcriptional programs associated with apoptosis, inflammation, differentiation, and cell survival.

Genetic studies have identified MAP2K4 as a candidate tumor suppressor gene, with loss-of-function mutations or deletions reported in several human cancers, underscoring its relevance to oncology research. Its central position in the stress-signaling network makes it a valuable target for both basic research and translational drug discovery programs.

Biochemical Properties of Recombinant Human MAP2K4 Protein

Recombinant Human MAP2K4 Protein is produced using recombinant expression technology to yield a highly purified, biologically active form of the human MAP2K4 kinase. The recombinant protein retains the dual-specificity catalytic activity characteristic of the native enzyme, enabling it to phosphorylate both threonine and tyrosine residues on its substrates.

Key biochemical attributes include:

• Species: Human
• Protein aliases: MKK4, SEK1, JNKK1, SAPKK1, MAP kinase kinase 4
• Enzyme class: Dual-specificity MAP kinase kinase (Ser/Thr and Tyr kinase activity)
• Biological activity: Activates JNK and p38 MAPK substrates in vitro
• Formulation: Supplied in a buffer optimized for protein stability and enzymatic activity; store according to datasheet recommendations to preserve activity

Researchers should consult the product-specific datasheet for precise molecular weight, purity grade, specific activity values, and recommended storage conditions, as these parameters are lot-specific and subject to quality control verification.

Research Applications

Recombinant Human MAP2K4 Protein supports a broad range of experimental workflows relevant to cell signaling, oncology, and drug discovery:

• In vitro kinase assays: MAP2K4 can be used directly in radiometric or fluorescence-based kinase assays to measure its activity toward JNK or p38 MAPK substrate peptides or proteins, enabling inhibitor profiling and IC50 determination.
• Substrate phosphorylation studies: Researchers studying JNK or p38 pathway activation can use recombinant MAP2K4 to phosphorylate downstream substrates in cell-free systems, providing mechanistic insight without the confounding effects of cellular context.
• Western blot and ELISA: As a well-characterized antigen, recombinant MAP2K4 can serve as a positive control or standard in immunoassays detecting MAP2K4 expression or phosphorylation status.
• Drug screening and target validation: The protein is suitable for high-throughput screening campaigns targeting the MAPK/JNK axis, supporting the identification of novel small-molecule inhibitors with potential therapeutic relevance in cancer, neurodegeneration, and inflammatory disease.
• Protein interaction studies: MAP2K4 can be employed in pull-down assays or surface plasmon resonance (SPR) experiments to characterize protein–protein interactions within the stress-kinase signaling complex.

Handling, Storage, and Quality Considerations

To maintain the biological activity and integrity of Recombinant Human MAP2K4 Protein, adherence to proper handling and storage protocols is essential:

• Storage temperature: Aliquot upon receipt and store at –70 °C or below for long-term stability. Avoid repeated freeze–thaw cycles, which can lead to loss of enzymatic activity and protein aggregation.
• Reconstitution: If supplied lyophilized, reconstitute in the buffer recommended on the product datasheet. Allow the vial to equilibrate to room temperature before opening, and mix gently — do not vortex.
• Working concentration: Optimize the working concentration empirically for each assay format. Begin with the range recommended in the datasheet and titrate as necessary.
• Carrier protein: When working at very low protein concentrations, consider supplementing with a carrier protein (e.g., BSA) to minimize non-specific adsorption to vessel surfaces.
• Quality control: Each lot of recombinant MAP2K4 from Aladdin Scientific is subject to quality control testing for purity (typically assessed by SDS-PAGE) and biological activity. Refer to the certificate of analysis (CoA) for lot-specific data.

Always consult the current product datasheet for the most accurate and up-to-date handling instructions.

Frequently asked questions

What is MAP2K4 and why is it important in cell signaling research?

MAP2K4 (also known as MKK4 or SEK1) is a dual-specificity kinase that sits at a pivotal node in the stress-activated MAPK signaling network, directly activating both JNK and p38 MAPK. Its roles in apoptosis, inflammation, differentiation, and tumor suppression make it a high-priority target for researchers in oncology, immunology, and neuroscience.

What applications is Recombinant Human MAP2K4 Protein validated for?

Recombinant Human MAP2K4 Protein is suitable for in vitro kinase assays, Western blot, ELISA, drug screening, and protein–protein interaction studies. For specific validated applications and recommended assay conditions, please refer to the product datasheet provided with each lot.

How should Recombinant Human MAP2K4 Protein be stored to maintain activity?

The protein should be aliquoted upon receipt and stored at –70 °C or below. Repeated freeze–thaw cycles should be avoided as they can degrade enzymatic activity. Always follow the storage instructions on the product datasheet and certificate of analysis for lot-specific guidance.

Can Recombinant Human MAP2K4 Protein be used for inhibitor screening?

Yes. Recombinant Human MAP2K4 Protein is well-suited for high-throughput and targeted inhibitor screening assays, including biochemical kinase inhibition assays used to determine IC50 values for candidate small molecules targeting the JNK/MAPK signaling axis.

What are the common aliases for MAP2K4?

MAP2K4 is also referred to as MKK4, SEK1, JNKK1, SAPKK1, and MAP kinase kinase 4. These names are used interchangeably in the literature, so researchers should be aware of this when searching databases or reviewing publications.

References

1. Dérijard B, et al. Independent human MAP-kinase signal transduction pathways defined by MEK and MKK isoforms. Science. 1995;267(5198):682-685.
2. Sanchez I, et al. Role of SAPK/ERK kinase-1 in the stress-activated pathway regulating transcription factor c-Jun. Nature. 1994;372(6508):794-798.
3. Su GH, et al. Alterations in pancreatic, biliary, and colon cancers of the gene encoding the MAP kinase kinase 4. Cancer Research. 1998;58(18):4339-4343.
4. Davis RJ. Signal transduction by the JNK group of MAP kinases. Cell. 2000;103(2):239-252.

Products are supplied for research and development use only. Not for use in humans, animals, diagnosis, or therapy.