Biological Background of IL31RA

Interleukin-31 receptor subunit alpha (IL31RA), also referred to as GPL or IL-31 RA, is a type I cytokine receptor that serves as one of two subunits forming the functional IL-31 receptor complex. The second subunit is oncostatin M receptor beta (OSMRβ). Together, IL31RA and OSMRβ bind their cognate ligand, IL-31, a cytokine primarily secreted by activated CD4+ T helper type 2 (Th2) cells.

Upon IL-31 binding, the receptor complex initiates intracellular signaling through the Janus kinase (JAK) / signal transducer and activator of transcription (STAT) pathway, as well as MAPK and PI3K cascades. These downstream events regulate gene expression programs associated with inflammation, epithelial barrier dysfunction, pruritus (itch), and tissue remodeling. IL31RA is expressed on multiple cell types including keratinocytes, dorsal root ganglion neurons, airway epithelial cells, monocytes, and macrophages, underlining its roles in skin homeostasis and atopic diseases.

Dysregulated IL-31/IL31RA signaling has been implicated in atopic dermatitis, asthma, allergic rhinitis, and certain hematological malignancies. IL31RA has consequently become an important target for therapeutic antibodies and a key protein of interest for basic and translational research into type 2 inflammatory diseases.

Protein Specifications and Quality Control

Recombinant Human IL31RA Protein (Aladdin SKU: rp368365) is produced using a recombinant expression system designed to yield a soluble, bioactive extracellular domain of human IL31RA. The following specifications are typical for recombinant receptor proteins of this class; always confirm exact values against the current product datasheet before use.

• Protein form: Typically the extracellular domain of human IL31RA, often fused to an affinity tag (e.g., His-tag or Fc-tag) to facilitate purification and detection.
• Purity: ≥90% as assessed by SDS-PAGE under reducing conditions; endotoxin levels controlled to minimize interference in cell-based assays.
• Formulation: Usually supplied as a lyophilized powder or liquid in a physiological buffer (e.g., PBS with carrier protein such as BSA). Refer to the datasheet for lot-specific details.
• Biological activity: Confirmed by a functional binding or inhibition assay demonstrating interaction with IL-31 ligand; specific ED50 values are lot-dependent and stated on the Certificate of Analysis (CoA).

Aladdin Scientific performs SDS-PAGE and, where applicable, functional bioassays as standard quality control steps. Lot-specific CoA documents are available upon request.

Reconstitution, Storage, and Handling Protocol

Proper reconstitution and storage are critical to maintaining the bioactivity of Recombinant Human IL31RA Protein. Follow the steps below and always cross-reference the product-specific datasheet for lot-dependent instructions.

Reconstitution

1. Briefly centrifuge the vial (1,000–2,000 × g, 30 seconds) before opening to collect lyophilized material at the bottom.
2. Reconstitute in sterile, deionized water or the buffer recommended on the datasheet (typically PBS, pH 7.4) to a concentration of 0.1–1.0 mg/mL. Adding a carrier protein (0.1% BSA) is recommended if the protein will be used at low concentrations or stored for extended periods.
3. Gently mix by pipetting or by rolling the vial. Do NOT vortex, as this may cause protein denaturation and aggregation.
4. Allow the protein to dissolve completely at room temperature for 10 minutes, then place on ice.

Storage Conditions

• Short-term (≤1 week): Store at 4 °C.
• Long-term: Aliquot into single-use volumes and store at -20 °C or -80 °C. Aliquoting prevents loss of activity due to repeated freeze-thaw cycles.
• Avoid repeated freeze-thaw cycles; each cycle can significantly reduce bioactivity.

Working Conditions

• Thaw aliquots on ice before use.
• Keep protein on ice during experimental setup.
• Do not expose to temperatures above 37 °C for extended periods.

Experimental Applications and Assay Guidance

Recombinant Human IL31RA Protein is suitable for a range of in vitro research applications. Below are the most common uses and practical guidance for each.

ELISA and Binding Assays

IL31RA is commonly used as a capture or detection reagent in sandwich ELISA formats designed to quantify IL-31 ligand. As a coating antigen, it can also be used to screen for IL31RA-binding antibodies or small molecules. Use at concentrations typically in the range of 0.5–2 µg/mL for plate coating; optimize empirically for each assay system.

Receptor-Ligand Interaction Studies

Surface plasmon resonance (SPR), bio-layer interferometry (BLI), and co-immunoprecipitation (co-IP) assays can employ recombinant IL31RA to characterize binding kinetics (KD, kon, koff) between IL31RA and IL-31 or candidate blocking molecules. Ensure the protein is free of aggregates before use by filtering through a 0.22 µm membrane or performing size-exclusion chromatography.

Cell-Based Functional Assays

When used as a soluble receptor (decoy receptor approach), recombinant IL31RA extracellular domain can neutralize IL-31 bioactivity in cell culture systems. This approach helps validate downstream signaling (JAK1/2, STAT3/5 phosphorylation) and establishes IL-31 dependency in a cellular model of interest.

Western Blot and SDS-PAGE

The purified protein can serve as a positive control or molecular weight marker in Western blot experiments using anti-IL31RA antibodies. Run under both reducing and non-reducing conditions to assess disulfide bond integrity.

Safety, Regulatory Status, and Ordering Information

Research Use Only (RUO): Recombinant Human IL31RA Protein (SKU: rp368365) is intended for in vitro research purposes only. It is not approved or validated for use in diagnostic, therapeutic, or veterinary applications.

Safety Handling: As with all protein reagents, handle with standard laboratory precautions. Wear appropriate personal protective equipment (gloves, lab coat, eye protection). Although IL31RA itself is not classified as a biohazardous material, follow institutional biosafety guidelines. Consult the Safety Data Sheet (SDS) for full hazard information.

Disposal: Dispose of protein solutions and contaminated materials according to local institutional and regulatory guidelines for biological laboratory waste.

Ordering: Recombinant Human IL31RA Protein is available from Aladdin Scientific under SKU rp368365. Contact your local Aladdin representative or visit the Aladdin Scientific website to request a quote, access the current datasheet, or obtain a Certificate of Analysis for a specific lot.