Recombinant Human G3BP2 Protein: Handling & Usage Protocol

Recombinant Human G3BP2 Protein is a key regulator of stress granule assembly and RNA metabolism, offered by Aladdin Scientific to support mechanistic studies in cellular stress response pathways.

Product Name

Recombinant Human G3BP2 Protein

SKU

rp367466

Protein Function

Stress granule nucleation and RNA metabolism regulation

Species Origin

Human (Homo sapiens)

Application Areas

Stress granule biology, RNA-binding assays, signal transduction studies

Storage Recommendation

Avoid repeated freeze-thaw cycles; aliquot upon reconstitution

Overview of G3BP2 and Its Biological Role

G3BP2 (GTPase-activating protein (SH3 domain)-binding protein 2) is a member of the G3BP family of RNA-binding proteins. It plays a central role in the nucleation and assembly of stress granules (SGs) — cytoplasmic ribonucleoprotein condensates that form in response to various cellular stresses such as oxidative stress, heat shock, viral infection, and endoplasmic reticulum stress.

G3BP2 shares functional and structural similarity with its paralog G3BP1, including an NTF2-like domain responsible for dimerization and protein–protein interactions, an acidic region, a PXXP motif, an RNA recognition motif (RRM), and an RGG domain for RNA binding. G3BP2 is implicated in the regulation of mRNA stability, translational reprogramming under stress, and has been reported to interact with viral components, making it relevant to antiviral innate immunity research.

Recombinant Human G3BP2 Protein from Aladdin Scientific (SKU: rp367466) enables researchers to conduct in vitro biochemical and biophysical studies of stress granule formation, phase separation, protein–protein interaction, and RNA-binding activity.

Reconstitution and Storage Protocol

Materials Required:

• Sterile deionized water or the buffer recommended in the product datasheet
• Low-protein-binding microcentrifuge tubes
• Ice bucket
• Micropipettes and sterile tips

Reconstitution Steps:

1. Allow the lyophilized protein vial to equilibrate to room temperature for 10–15 minutes before opening to minimize condensation.
2. Briefly centrifuge the vial (1,000 × g, 30 seconds) to pellet lyophilized material to the bottom.
3. Reconstitute the protein by adding the recommended volume of sterile water or buffer (as specified on the product datasheet) slowly along the side of the vial. Do not pipette directly onto the lyophilized cake.
4. Gently swirl the vial. Do not vortex, as this can cause protein denaturation and aggregation.
5. Allow the vial to sit at room temperature for 5–10 minutes to ensure complete dissolution.
6. Visually inspect for clarity. If the solution appears turbid, centrifuge at 10,000 × g for 5 minutes at 4°C and use the supernatant.

Storage Recommendations:

• Aliquot reconstituted protein into single-use volumes using low-protein-binding tubes to avoid repeated freeze-thaw cycles.
• Store aliquots at −80°C for long-term storage.
• For short-term use (within 1 week), store at 4°C. Add a carrier protein (e.g., 0.1% BSA) if diluting to very low concentrations.
• Avoid repeated freeze-thaw cycles, as this significantly reduces protein activity and integrity.

Experimental Applications and Usage Guidelines

Recombinant Human G3BP2 Protein is suitable for a variety of in vitro research applications. The following guidelines outline common experimental uses:

1. In Vitro Stress Granule Phase Separation Assays

G3BP2 can undergo liquid-liquid phase separation (LLPS) in vitro under appropriate buffer conditions and molecular crowding agents (e.g., polyethylene glycol). Use freshly reconstituted protein at concentrations typically in the range of 1–20 µM (verify optimal concentration with product datasheet) and monitor condensate formation by fluorescence or differential interference contrast (DIC) microscopy.

2. Protein–Protein Interaction Studies

G3BP2 interacts with a range of stress granule components (e.g., Caprin-1, USP10, eIF4A) and viral proteins. Recombinant G3BP2 can be used in pull-down assays, co-immunoprecipitation validations, surface plasmon resonance (SPR), or isothermal titration calorimetry (ITC) to characterize binding partners and affinities.

3. RNA-Binding Assays

G3BP2 binds mRNA via its RRM and RGG domains. Electrophoretic mobility shift assays (EMSA) or filter-binding assays can be performed with purified recombinant G3BP2 and target RNA substrates to study RNA recognition specificity and affinity.

4. Biochemical Reconstitution

G3BP2 can be incorporated into reconstituted stress granule systems alongside other core components to study condensate material properties and regulatory mechanisms.

General Tips:

• Determine working concentration empirically for each assay format.
• Include appropriate positive and negative controls.
• Keep protein on ice during experimental setup to minimize activity loss.

Quality Control and Troubleshooting

Quality Control Checks:

• Verify protein concentration after reconstitution using a compatible colorimetric assay (e.g., BCA or Bradford assay).
• Confirm protein integrity by SDS-PAGE under reducing conditions; a single band at the expected molecular weight of G3BP2 indicates good purity.
• For activity-sensitive applications, run a functional benchmark assay (e.g., EMSA or phase separation assay) with each new lot.

Common Issues and Solutions:

Issue	Possible Cause	Solution
Turbid solution after reconstitution	Protein aggregation	Centrifuge at 10,000 × g, 4°C, 5 min; use supernatant
Low or no activity in assay	Repeated freeze-thaw or improper storage	Use freshly aliquoted protein; check storage temperature
Multiple bands on SDS-PAGE	Degradation or contaminants	Contact Aladdin Scientific technical support; note lot number
Poor phase separation in LLPS assay	Sub-optimal protein or buffer concentration	Optimize protein concentration and crowding agent percentage

Safety, Disposal, and Regulatory Notes

Safety Precautions:

• Recombinant Human G3BP2 Protein is intended for research use only (RUO) and is not approved for human therapeutic or diagnostic applications.
• Handle all recombinant proteins using standard laboratory safety practices, including the use of gloves, laboratory coat, and eye protection.
• Although G3BP2 is not classified as a biohazardous agent, treat all biological materials with appropriate caution per institutional biosafety guidelines.

Disposal:

• Dispose of protein solutions and contaminated materials according to your institution's biological waste disposal regulations.
• Inactivate protein-containing solutions before disposal if required by institutional policy (e.g., autoclaving or chemical inactivation).

Regulatory Notice:

• This product is for in vitro research use only. It has not been evaluated for safety or efficacy in humans or animals by any regulatory agency.
• Export of this product may be subject to national and international regulations. Please consult your institution's compliance office if needed.

Frequently asked questions

What is the recommended reconstitution buffer for Recombinant Human G3BP2 Protein?

The recommended reconstitution buffer is specified on the individual product datasheet for SKU rp367466. In general, sterile deionized water or a physiological buffer such as PBS (pH 7.4) is commonly used. Always refer to the specific product datasheet for lot-specific recommendations.

How should I store Recombinant Human G3BP2 Protein to maintain its activity?

After reconstitution, aliquot the protein into single-use volumes in low-protein-binding tubes and store at −80°C for long-term preservation. Avoid repeated freeze-thaw cycles, as they significantly reduce protein activity. For short-term use within one week, storage at 4°C is acceptable.

What research applications is Recombinant Human G3BP2 Protein suitable for?

Recombinant Human G3BP2 Protein is suitable for in vitro applications including stress granule phase separation (LLPS) assays, protein–protein interaction studies (pull-down, SPR, ITC), RNA-binding assays (EMSA), and biochemical reconstitution of stress granule systems. It is not intended for diagnostic or therapeutic use.

How can I confirm the integrity and purity of Recombinant Human G3BP2 Protein after reconstitution?

Run an SDS-PAGE analysis under reducing conditions and verify the presence of a single band at the expected molecular weight of G3BP2. Additionally, measure protein concentration using a BCA or Bradford assay. For activity confirmation, perform a functional assay such as EMSA or a phase separation assay with each new protein lot.

Is Recombinant Human G3BP2 Protein suitable for use in cell-based assays?

Recombinant Human G3BP2 Protein is primarily optimized for in vitro biochemical assays. If cell-based delivery is intended (e.g., protein transfection), additional optimization such as the use of protein delivery reagents would be required. Consult Aladdin Scientific technical support for guidance on specific experimental designs.

References

1. Kedersha N, et al. G3BP–Caprin1–USP10 complexes mediate stress granule condensation and associate with 40S subunits. Journal of Cell Biology. 2016.
2. Yang P, et al. G3BP1 is a tunable switch that triggers phase transition to promote stress granule assembly. Cell. 2020.
3. Tourriere H, et al. The RasGAP-associated endoribonuclease G3BP assembles stress granules. Journal of Cell Biology. 2003.

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