Recombinant Mouse FGF R2β (IIIc)

Recombinant Mouse FGF R2β (IIIc) is used in research applications to study and manipulate fibroblast growth factor (FGF) signaling, particularly in contexts where the specific receptor isoform FGFR2β (IIIc) is relevant, such as development, tissue repair, stem cell biology, and disease modeling.

FGFR2β (IIIc) is a splice variant of the fibroblast growth factor receptor 2 (FGFR2) that determines ligand specificity and tissue distribution, playing a critical role in mediating the effects of various FGFs, including FGF-2 and FGF-10, on cell proliferation, differentiation, migration, and survival. Using the recombinant form allows for controlled, reproducible studies of FGF signaling pathways in vitro and in vivo.

Key research applications and rationales include:

• Dissecting FGF signaling mechanisms: Recombinant FGFR2β (IIIc) enables the study of ligand-receptor interactions, downstream signaling cascades (such as PI3K/AKT, ERK1/2, and PLCγ pathways), and their biological outcomes in different cell types.
• Developmental biology: FGFR2β (IIIc) is essential for epithelial–mesenchymal interactions during organogenesis, including the digestive tract, craniofacial structures, and limb development in mice.
• Stem cell and tissue engineering research: FGFR2β (IIIc) mediates FGF-induced proliferation, migration, and differentiation of mesenchymal stem cells, neural progenitors, and other cell types, making it valuable for regenerative medicine studies.
• Disease modeling: Aberrant FGFR2β (IIIc) signaling is implicated in developmental disorders, cancer, and tissue fibrosis, so recombinant receptor can be used to model these conditions or screen for therapeutic modulators.
• Receptor-ligand binding assays: Recombinant FGFR2β (IIIc) is used in biochemical assays to quantify binding affinities and specificities of FGF ligands, or to inhibit endogenous FGF signaling in cell-based experiments.

Using the recombinant mouse protein ensures species compatibility for mouse models and cell lines, reducing cross-species variability and improving physiological relevance. The IIIc isoform is particularly important in mesenchymal and some epithelial tissues, where it mediates responses to a distinct subset of FGF ligands compared to the IIIb isoform.

In summary, recombinant Mouse FGF R2β (IIIc) is a powerful tool for elucidating FGF signaling roles in development, regeneration, and disease, and for developing targeted interventions in these pathways.

Recombinant Mouse FGF R2β (IIIc) is not suitable as a standard for quantification or calibration in ELISA assays designed to measure FGF ligands (such as FGF-21 or FGF-2); it is a receptor protein, not the analyte targeted by typical FGF ELISAs.

ELISA standards must be chemically and immunologically identical to the analyte being measured. For quantifying FGF-21 or FGF-2, the standard should be recombinant or purified FGF-21 or FGF-2, respectively, not their receptor proteins. Recombinant FGF R2β (IIIc) is a fragment of the fibroblast growth factor receptor, not the ligand, and will not be recognized by antibodies specific for FGF-21 or FGF-2 in standard ELISA kits.

Key points:

• ELISA standards are typically the same protein as the target analyte (e.g., recombinant FGF-21 for FGF-21 ELISA).
• FGF R2β (IIIc) is a receptor isoform, not the ligand. ELISA antibodies for FGF-21 or FGF-2 do not recognize FGF receptors as standards.
• Cross-reactivity studies in FGF-21 and FGF-2 ELISA kits show that FGF R2β (IIIc) does not interfere or serve as a quantifiable standard in these assays.
• Using a receptor protein as a standard would result in inaccurate quantification, as the assay is not calibrated for its detection.

For accurate quantification or calibration in ELISA assays, use a recombinant or purified preparation of the specific FGF ligand you wish to measure, not the receptor protein. If you need to quantify FGF R2β (IIIc) itself, a custom ELISA with antibodies specific to this receptor isoform would be required.

Recombinant Mouse FGF R2β (IIIc) has been validated primarily for use in cell-based functional assays that assess its ability to bind fibroblast growth factors (FGFs) and modulate FGF-dependent cellular responses, particularly in the context of proliferation and differentiation of mouse fibroblast cells. Published research also implicates the endogenous Fgfr2IIIc isoform in the regulation of bone formation and osteoblast/chondrocyte biology, but direct applications of the recombinant protein in other assay types are less well documented.

Key validated applications in published research:

• Cell Proliferation Assays:
  The recombinant protein has been validated by its ability to inhibit FGF-acidic (FGF1)-dependent proliferation of NR6R-3T3 mouse fibroblast cells. The effective dose (ED50) for this inhibition is typically 0.5–1.5 ng/mL, demonstrating its functional activity as a decoy or competitor for FGF ligands in vitro.

• Mechanistic Studies of FGF Signaling:
  The recombinant receptor is used to study the specificity and biological activity of FGF ligands, as well as the downstream effects of FGF signaling in various cellular contexts, including cell growth, differentiation, angiogenesis, and wound healing.

• Bone Biology Research:
  The IIIc isoform of Fgfr2 (the endogenous counterpart of the recombinant protein) has been shown to be a positive regulator of ossification, affecting osteoblast and chondrocyte lineages in mouse models. While this finding is based on genetic and expression studies, recombinant FGF R2β (IIIc) could be used in vitro to dissect these pathways further.

Additional context:

• Assay Types:
  The most direct validation is in cell-based proliferation assays using mouse fibroblast lines. There is no direct evidence in the search results for use in Western blot, ELISA, immunohistochemistry, or in vivo animal studies with the recombinant protein itself, though such applications are theoretically possible given the protein’s specificity and activity profile.

• Research Areas:
  The recombinant protein is relevant for studies in developmental biology, tissue regeneration, cancer biology, and skeletal biology, wherever FGF signaling via the IIIc isoform is implicated.

• Mechanism:
  The recombinant FGF R2β (IIIc) acts as a soluble decoy receptor, binding FGF ligands and preventing them from activating endogenous cell-surface FGF receptors, thus modulating downstream signaling events.

Summary Table: Validated Applications

If you require protocols or more technical details for a specific application, please specify the assay or research context.

To reconstitute and prepare Recombinant Mouse FGF R2β (IIIc) protein for cell culture experiments, follow these best-practice steps based on protocols for similar recombinant FGF receptor proteins and general recombinant protein handling:

1. Centrifuge the Lyophilized Vial
   Before opening, briefly centrifuge the vial (20–30 seconds in a microcentrifuge) to ensure all protein is at the bottom and not stuck to the cap or sides.

2. Reconstitution

   • Use sterile, distilled water or the specific buffer recommended in the product datasheet (if available). Most recombinant FGF receptor proteins are reconstituted in sterile water or PBS without calcium or magnesium.
   • Add water slowly to achieve a final concentration between 0.1–1.0 mg/mL (for example, add 100–1000 μL per 100 μg protein).
   • Gently swirl or invert the vial to dissolve. Avoid vigorous pipetting or vortexing, which can denature the protein.

3. Carrier Protein (Optional but Recommended for Stability)

   • For enhanced stability, especially at low concentrations, add a carrier protein such as 0.1% BSA (bovine serum albumin) to the solution.
   • This is particularly important if you plan to store aliquots or use the protein at concentrations below 0.1 mg/mL.

4. Aliquot and Storage

   • Immediately aliquot the reconstituted protein into small volumes to avoid repeated freeze-thaw cycles, which can cause denaturation and loss of activity.
   • Store aliquots at –20°C to –70°C for long-term storage, or at 2–8°C for up to one month if you will use the protein soon.
   • Avoid repeated freeze-thaw cycles.

5. Preparation for Cell Culture

   • Before adding to cell culture, dilute the protein to the desired working concentration using sterile cell culture medium or buffer containing carrier protein.
   • Filter the final working solution through a 0.2 μm sterile filter if sterility is required.

6. Quality Check (Optional)

   • Confirm protein integrity by SDS-PAGE if needed.

Summary Table: Reconstitution and Storage

Notes:

• Always consult the lot-specific datasheet for your protein for any unique instructions.
• If the protein is an Fc chimera, as is common for FGF R2β (IIIc), the above protocol remains appropriate.
• For cell-based assays, ensure the final buffer is compatible with your cells (e.g., free of preservatives and at physiological pH).

If you need a protocol tailored to a specific application (e.g., ELISA, Western blot, or functional cell assays), please specify.