Product Name: MKK4-pS257
Product Number: AB-PK715
Size: 25 µg      Price:89.00
      $US
Target Full Name: MAPK/ERK protein-serine kinase 4 (MKK4); Dual specificity mitogen-activated protein kinase kinase 4

Target Alias: c-Jun N- terminal kinase kinase 1; C-JUN N-terminal kinase kinase 1; JNK activating kinase 1; JNK kinase 1; JNKK1; Kinase SEK1; MAP2K4; SEK1; SERK1; SAPKK1; SAPKK-1; SKK1; CCDS11162.1; ENSG00000065559

Product Type Specific: Protein kinase phosphosite-specific antibody

Antibody Code: PK715

Antibody Target Type: Phosphosite-specific

Antibody Phosphosite: S257

Protein UniProt: P45985

Protein SigNET: P45985

Antibody Type: Polyclonal

Antibody Host Species: Rabbit

Antibody Immunogen Source: Human MKK4 (MAP2K4, MEK4) sequence peptide Cat. No.: PE-04ANU99

Antibody Immunogen Sequence: LVD(pS)IAK(bA)C

Antibody Immunogen Description: Corresponds to amino acid residues L254 to K260; In the protein kinase catalytic domain activation T loop region between subdomains VII and VIII.

Production Method: The immunizing peptide was produced by solid phase synthesis on a multipep peptide synthesizer and purified by reverse-phase hplc chromatography. Purity was assessed by analytical hplc and the amino acid sequence confirmed by mass spectrometry analysis. This peptide was coupled to KLH prior to immunization into rabbits. New Zealand White rabbits were subcutaneously injected with KLH-coupled immunizing peptide every 4 weeks for 4 months. The sera from these animals was applied onto an agarose column to which the immunogen peptide was thio-linked. Antibody was eluted from the column with 0.1 M glycine, pH 2.5. Subsequently, the antibody solution was neutralized to pH 7.0 with saturated Tris.This antibody was also subject to negative purification over phosphotyrosine-agarose.

Antibody Modification: Unconjugated. Contact KInexus if you are interest in having the antibody biotinylated or coupled with fluorescent dyes.

Antibody Concentration: 42370 mg/ml

Storage Buffer: Phosphate buffered saline pH 7.4, 0.05% Thimerasol

Storage Conditions: For long term storage, keep frozen at -40°C or lower. Stock solution can be kept at +4°C for more than 3 months. Avoid repeated freeze-thaw cycles.

Product Use: Western blotting | Antibody microarray

Antibody Dilution Recommended: 2 µg/ml for immunoblotting

Antibody Potency: Very strong immunoreactivity with immunogen peptide on dot blots. Very strong immunoreactivity with recombinant human MKK4 on protein dot blots.

Antibody Species Reactivity: Human

Antibody Positive Control: The observed molecular mass of the processed target protein on SDS-PAGE gels is reported to be around 42-46 kDa.

Antibody Specificity: High

Antibody Cross Reactivity: No cross-immunoreactivity on protein dot blots with recombinant human MEK1 or MKK6.

Related Product 1: MKK4-pS257 blocking peptide

Related Product 2: MKK4-1 pan-specific antibody (Cat. No.: AB-NK103-4)

Related Product 3: MKK4-2 pan-specific antibody (Cat. No.: AB-NK103-5)

Related Product 4: MKK4-3 pan-specific antibody (Cat. No.: AB-NK103-6)

Related Product 5: MEK4-XI (MKK4-4) pan-specific antibody (Cat. No.: AB-NK103-7)

Related Product 6: MKK4-pS80 phosphosite-specific antibody (Cat. No.: AB-PK716)

Scientific Background: MKK4 (MAP2K4, MEK4) is a dual specificity protein kinase of the STE group and STE7 family Phosphorylation of S257 and T261 increases phosphotransferase activity. Phosphorylation of S80 inhibits its phosphotransferase activity. It acts as a critical component in the MAP kinase (MAPK) and the stress-activated protein kinase/c-Jun N-terminal kinase (SAP/JNK) signalling pathways. It has a role in maintaining peripheral lymphoid homeostasis and apoptosis. Mutations and deletions of this genes leads to dysregulated JNK signalling and promotes oncogenesis. MKK4 appears to be a tumour suppressor protein (TSP), but it may also promote metastasis. Cancer-related mutations in human tumours point to a loss of function of the protein kinase. The active form of the protein kinase normally acts to inhibit tumour cell proliferation. However, significantly elevated expression of MKK4 has been observed in invasive pancreatic cancer specimens, indicating a possible role for the protein in tumourigenesis. MKK4 over-expression is correlated with increased expression of heat shock protein 27 (HSP27) and matrix metalloproteinase 2 (MMP-2) protein, which are required for the increased invasive phenotype of the cells. Therefore, MKK4 appears to have an important role in the promotion of metastasis in pancreatic cancer cells. Insertional mutagenesis studies in mice support a role for this protein kinase in mouse cancer oncogenesis.
Figure 1. Epitope mapping of MKK4-pS257 antibody with similar phosphopeptides on dot blots.


Figure 2. Identification of phosphosites related to MKK4-pS257.