| Field | Specification |
|---|---|
| Activity | |
| Alternative Names | Ribosomal protein S6 kinase alpha-4 (Rps6ka4); (S6K-alpha-4)(90 kDa ribosomal protein S6 kinase 4)(Nuclear mitogen- and stress-activated protein kinase 2)(RSK-like protein kinase)(RLSK) |
| Conjugate | |
| Endotoxin Level | |
| Expression System | |
| Form | Liquid or Lyophilized powder |
| Molecular Weight | |
| Product Type | |
| Protein Length | |
| Purity | |
| Reconstitution | |
| Species | |
| Storage | |
| Target | |
| UniProt # |
Overview
Recombinant Mouse Ribosomal protein S6 kinase alpha-4 (Rps6ka4) is a recombinant protein reagent derived from Mus musculus (Mouse) and produced in Baculovirus. It is commonly used to support Signal Transduction research by enabling enzyme activity assays, kinetics/structure–function studies and inhibitor or substrate screening in controlled in vitro settings.
Key elements and design rationale
- Expressed region: 1-773aa. Region selection can focus on functional domains, improve solubility, or isolate interaction surfaces for targeted studies.
- Expression system: Baculovirus. Expression host can influence folding and the presence/absence of post-translational modifications.
- Tag / fusion: N-terminal 10xHis-tagged and C-terminal Myc-tagged. Tags can support purification and detection; evaluate potential tag effects when studying sensitive interactions.
- Molecular weight (reported): 89.7 kDa. Apparent size may vary with tags, processing, and gel conditions.
When comparing results across batches or platforms, interpret signals in the context of construct design (region, tags) and expression host, especially for modification-dependent interactions.
Biological background
The gene commonly associated with this target is Rps6ka4. Rps6ka4 refers to a protein target that is studied across multiple biological contexts; annotations and nomenclature can vary by species and isoform. This product corresponds to the Mus musculus (Mouse) sequence context, which can be important when comparing homologs or orthologs across model systems. For curated functional annotations, domains, and sequence features, consult primary databases (e.g., UniProt/NCBI) and the recent literature for the specific organism and isoform.
Research relevance and current trends
- Using recombinant proteins to enable quantitative binding measurements and reagent benchmarking.
- Studying domain- and isoform-specific effects in pathway models and interaction networks.
- Developing robust, reproducible assays that connect molecular readouts to cellular phenotypes.
Relevance: Serine/threonine-protein kinase that is required for the mitogen or stress-induced phosphorylation of the transcription factors CREB1 and ATF1 and for the regulation of the transcription factor RELA, and that contributes to gene activation by histone phosphorylation and functions in the regulation of inflammatory genes. Phosphorylates CREB1 and ATF1 in response to mitogenic or stress stimuli such as UV-C irradiation, epidermal growth factor (EGF) and anisomycin. Plays an essential role in the control of RELA transcriptional activity in response to TNF. Phosphorylates 'Ser-10' of histone H3 in response to mitogenics, stress stimuli and EGF, which results in the transcriptional activation of several immediate early genes, including proto-oncogenes c-fos/FOS and c-jun/JUN. May also phosphorylate 'Ser-28' of histone H3. Mediates the mitogen- and stress-induced phosphorylation of high mobility group protein 1 (HMGN1/HMG14). In lipopolysaccharide-stimulated primary macrophages, acts downstream of the Toll-like receptor TLR4 to limit the production of pro-inflammatory cytokines. Functions probably by inducing transcription of the MAP kinase phosphatase DUSP1 and the anti-inflammatory cytokine interleukin 10 (IL10), via CREB1 and ATF1 transcription factors.
Common research applications
- Enzyme activity assays and kinetics measurements with defined substrates/cofactors.
- Inhibitor, activator, or substrate screening in biochemical assay formats.
- Structure–function analysis to interpret how sequence changes impact catalytic performance.
In quantitative assay development, changes in binding or activity readouts are typically interpreted relative to appropriate negative/positive controls and, where possible, orthogonal assay formats that support the same conclusion.
Notes for experimental interpretation
- Recombinant constructs may represent a defined region (domain) rather than the full-length protein; interpret results in the context of the expressed region.
- Tag or fusion elements can aid purification and detection but may influence binding surfaces or oligomerization; consider tag controls when relevant.
- Species and isoform differences can affect interaction partners and post-translational modifications; align experimental controls to the intended biological context.
What is protein expression and purification?
Why is there no/low protein expression?
b. Rare codons. You should optimize codons, use strains supplementing rare codons, induce at lower temperature or grow in poor media.
c. Protein toxicity. You should use promoters with tighter regulation or lower plasmid copy number. Use pLysS/pLysE bearing strains in T7-based systems or strains that are better for the expression of toxic proteins. Start induction at high OD and shorten induction time. Add glucose when using expression vectors containing lac-based promoters.
How to avoid inclusion bodies and improve soluble expression?
b. Incorrect disulfide bond formation. You should add fusion partners, including thioredoxin, DsbA, DsbC. Clone in a vector containing secretion signal peptide to cell periplasm. Use gamiB (DE3)strains with oxidative cytoplasmic environment. Lower inducer concentration and induction temperature.
c. Incorrect folding. You should use a fusion partner. Co-express with molecular chaperones. Use strains with cold-adapted chaperones. Supplement media with chemical chaperones and cofactors. Reduce the inducer concentration and add fresh media. Induce for a shorter time at low temperature.
Why is the molecular weight of protein smaller than the predicted?
b. Imbalanced translation process of fusion protein. You should change another fusion tag or move fusion tag to C-terminal. You should induce for a shorter time at low temperature or change to poor media.
c. Protein degradation. You should replace specific protease sites. Use protease deficient strains. Induce at high OD. You should induce for a shorter time at low temperature or use protease inhibitors when breaking cells.
Why is the actual band size different from the predicted?
b. Post-translational cleavage. Many proteins are synthesized as pro-proteins, and then cleaved to give the active form.
c. Splice variants. Alternative splicing may create different sized proteins from the same gene.
d. Relative charge. The composition of amino acids have different relative charge which will affect the electrophoretic mobility.
e. Multimers such as dimerisation of a protein. This is usually prevented in reducing conditions, although strong interactions can result in the appearance of higher bands.
f. Protein structure such as disulfide bond, protein secondary structure or protein 3D structure formation.
g. Hydrophobic proteins, such as transmembrane proteins, may have difficulties in migrating into the gel, and thus resulting in different multi-banded patterns.
How to express a protein with bioactivity? Why is the protein inactive?
a. Low solubility of the protein. You should fuse desired protein to a fusion partners and lower temperature.
b. Lack of essential post translational modification. You should change another expression system.
c. Incomplete folding. You should use a fusion partner and use strains with cold-adapted chaperones. Co-express with molecular chaperones at lower temperature. Monitor disulfide bond formation and allow further folding in vitro.
d. Mutations in cDNA. You should sequence plasmid before and after induction or use a recA− strain to ensure plasmid stability. Transform E. coli before each expression round.
Why are our protein products almost invisible in pipes?
Tips: Before opening the lid, we recommend to centrifuge in a small centrifuge for 20-30 seconds firstly to ensure that the contents are on the bottom of the tube. Our quality control steps ensure that the amount of protein contained in each tube is accurate, although sometimes you can’t see the protein powder, but the protein content in the tube is still very accurate.
How is the protein purified? Is the purity guaranteed?
Although we guarantee a minimum purity standard of >85%, some of the proteins we prepared have a purity of 95% or even 97%.
How should I reconstitute and store the products?
As for short-term storage or usage, please use sterile deionized water to completely reconstitute proteins to 0.1-1.0 mg/mL. Aliquot after 10-15 minutes if needed and store at 4℃.
As for long-term storage, the cytokines or recombinant proteins are recommended to add 5-50% of glycerol (final concentration) and aliquot for long-term storage at -20℃/-80℃. Our default final concentration of glycerol is 50%. Customers could use it as reference.
What types of tags do you use for fusion?
What is the impact of a given tag type and any potential biological activity of the protein?
Can you remove the endotoxin?
Can you offer aseptic manufacture processing?
How to determine species cross-reactivity of cytokines?
b. Many mouse cytokines may also have effect on human cells, however, the activity may be lower than the corresponding human cytokines.
c. One of the few human cytokines will be more active than corresponding mouse cytokines when acting on mouse cells, such as IL-7.
d. Interferon, GM-CSF, IL-3 and IL-4 and other cytokines are species-specific and almost have no activity on non-homologous cells.
e. In contrast, fibroblast growth factor (FGF) and neurotrophin are highly conserved and both have good activity on cells of different species.
What is the general preservative? Which kind of preservative do you usually add?
What is the general protectant? What kind of protectant do you usually add?
Can’t Find What You’re Looking For? We can help you source the best match or customize a recombinant protein solution for your study. Options may include species (human/mouse/rat), protein region/domain (full-length vs fragment), tag or label (His/GST/FLAG/biotin/fluorescent), expression system (E. coli/HEK293/insect), purity grade, formulation (buffer, carrier-free, glycerol-free), activity/functional validation (binding or enzymatic assays), endotoxin level (low-endotoxin for cell-based work), mutants/variants (point mutations, isoforms), and bulk or custom packaging. Click Talk to a Scientist to submit a request form, email us at support@biohippo.com, or explore our Research Services for additional support. Our team will be in contact with you shortly.
Research budgets are tight — we get it. That's why we've put together a fresh round of exclusive promotions designed to help you stock up on the reagents, kits, and consumables your lab depends on, without stretching your budget.
🔬 What's on offer right now:
10% Off Pre-Designed siRNA Sets — use code SIRNA10
20% Off Transmembrane Proteins — use code TM20
$50 Off All ELISA Kits — auto-applied at checkout (code ELISA50)
50% Off Lab Consumables + Free Shipping on orders $500+
15% Off Proteins from Trusted Suppliers — use code PROTEIN15
$99 Pipette Filler Promotion Package (reg. $236)
Save 10% on your first order of any R&D grade DENARASE® with code DENARASE10 at checkout.
