G3BP1 (Ab-232) Antibody

What is G3BP1 and what cellular functions does it perform?

G3BP1 (GTPase Activating Protein SH3 Domain Binding Protein 1) is a multifunctional protein involved in several critical cellular processes. It functions as one of the DNA-unwinding enzymes with a preference for partially unwound 3'-tailed substrates and demonstrates the ability to unwind partial RNA/DNA and RNA/RNA duplexes in an ATP-dependent manner . G3BP1 belongs to the heterogeneous nuclear RNA-binding protein family and serves as an important component of the Ras signal transduction pathway, specifically binding to the Ras-GTPase-activating protein by associating with its SH3 domain . The protein is also known by several synonyms including ATP-dependent DNA helicase VIII, GAP SH3 domain-binding protein 1, and hDH VIII .

G3BP1 plays significant roles in various cellular contexts, particularly in stress response pathways, RNA metabolism, and has been implicated in several disease processes. Its interactions with multiple binding partners, including USP10, CAPRIN1, OGFOD1, PRMT1, and EIF4G1, further underscore its importance in cellular signaling networks .

What applications can G3BP1 (Ab-232) Antibody be used for?

The G3BP1 (Ab-232) Antibody is suitable for multiple research applications, making it a versatile tool for investigating G3BP1 function and expression. Primary applications include:

• Western Blotting (WB): The antibody can be used at dilutions of 1:500 - 1:2000 for detecting G3BP1 phosphorylated at Serine 232 in protein extracts from various cell types, including 293 cells .

• Immunohistochemistry (IHC): Used at dilutions of 1:50 - 1:100, the antibody is effective for detecting the target protein in tissue sections, including paraffin-embedded human breast carcinoma samples .

• Immunofluorescence (IF): At dilutions of 1:100 - 1:200, the antibody works well for cellular localization studies in methanol-fixed cells such as HeLa cells .

• Enzyme-Linked Immunosorbent Assay (ELISA): The antibody can be utilized in ELISA-based protein detection methods .

• Immunocytochemistry (ICC): The antibody is suitable for detecting G3BP1 in cultured cells using immunocytochemical techniques .

These applications provide researchers with multiple approaches to investigate G3BP1 expression, localization, and phosphorylation status in various experimental contexts.

What is the significance of phosphorylation at Serine 232 in G3BP1?

Phosphorylation at Serine 232 represents a key post-translational modification of G3BP1 that regulates its functionality in cellular processes. The Phospho-G3BP1-S232 antibody specifically detects endogenous levels of G3BP1 only when phosphorylated at Serine 232 . This phosphorylation site is located in a region critical for G3BP1's activity and interactions with other proteins.

The amino acid sequence surrounding this phosphorylation site (S-S-S-P-A) appears to be conserved and functionally significant, as it is used as an immunogen for antibody production . The specific phosphorylation at Serine 232 likely plays a role in regulating G3BP1's involvement in stress granule assembly, RNA metabolism, and signal transduction pathways.

Understanding the phosphorylation status of G3BP1 at Serine 232 can provide insights into stress response mechanisms, disease processes, and cellular signaling networks. This makes the G3BP1 (Ab-232) antibody particularly valuable for studying the functional state of this protein under various physiological and pathological conditions.

How does G3BP1 function in stress granule formation and what role does Ser232 phosphorylation play?

G3BP1 serves as a critical nucleator of stress granules (SGs), cytoplasmic aggregates of stalled translation pre-initiation complexes that form during cellular stress conditions. The phosphorylation status of G3BP1 at Serine 232 appears to regulate its ability to form these structures. The Phospho-G3BP1 (Ser232) antibody enables researchers to specifically track the phosphorylated form of the protein during stress responses .

When investigating stress granule dynamics, it's important to consider that G3BP1 interacts with several other proteins, including USP10 and CAPRIN1, which have been documented in multiple publications as G3BP1 binding partners . These interactions may be influenced by the phosphorylation state of Serine 232. Experimental approaches using the G3BP1 (Ab-232) antibody can help elucidate how this phosphorylation affects protein-protein interactions during stress granule assembly and disassembly.

For comprehensive studies of stress granule dynamics, researchers should combine G3BP1 (Ab-232) antibody staining with markers for other stress granule components. This multi-parameter approach allows for more nuanced analysis of how G3BP1 phosphorylation correlates with stress granule formation, maturation, and resolution under various experimental conditions.

What is the relationship between G3BP1 and cancer progression?

G3BP1 has been implicated in multiple cancer types, with the G3BP1 (Ab-232) antibody providing a valuable tool for investigating its role in oncogenesis. Publications linking G3BP1 to neoplastic processes show particularly strong associations with breast neoplasms (>6 publications), lung diseases (>3 publications), liver diseases (>2 publications), and adenocarcinoma (>2 publications) .

The antibody has been successfully used for immunohistochemical analysis of paraffin-embedded human breast carcinoma samples, demonstrating its utility in cancer tissue studies . Additionally, G3BP1 has been linked to neoplasm metastasis and hepatocellular carcinoma in published research , suggesting its potential role in cancer progression and metastatic spread.

For researchers studying cancer biology, the G3BP1 (Ab-232) antibody offers the ability to investigate whether the phosphorylation status of G3BP1 at Serine 232 correlates with malignant transformation, invasiveness, or treatment response. This phospho-specific approach provides more detailed insights than studies examining only total G3BP1 levels, potentially identifying new mechanisms driving cancer progression that could be targeted therapeutically.

How can I optimize western blot protocols for detecting phosphorylated G3BP1?

Optimizing western blot protocols for phosphorylated G3BP1 detection requires careful attention to several technical parameters. Based on validation data from the antibody manufacturers, the following approach is recommended:

• Sample Preparation: Extract proteins from cells using buffers containing phosphatase inhibitors to preserve the phosphorylation state. The antibody has been validated using extracts from 293 cells .

• Protein Loading: Use approximately 25μg of protein per lane for optimal detection, as demonstrated in validated western blot analyses .

• Antibody Dilution: Use the G3BP1 (Ab-232) antibody at a dilution of 1:500 - 1:2000 for western blot applications .

• Secondary Antibody: HRP-conjugated Goat Anti-Rabbit IgG has been successfully used at a 1:10000 dilution in validation studies .

• Blocking: 3% BSA as a blocking buffer has proven effective in preventing non-specific binding .

For phospho-specific detection, it is advisable to include both phosphorylated and non-phosphorylated control samples. Additionally, including a phosphatase-treated control can help confirm the specificity of the phospho-signal. Given that the antibody has been purified via sequential chromatography on phospho- and non-phospho-peptide affinity columns , it shows high specificity for the phosphorylated form of G3BP1.

What are the recommended storage and handling conditions for G3BP1 (Ab-232) Antibody?

Proper storage and handling of the G3BP1 (Ab-232) antibody are essential for maintaining its activity and specificity. Based on manufacturer recommendations, the following guidelines should be observed:

• Long-term Storage: Store the antibody at -20°C for long-term preservation. This temperature is optimal for maintaining antibody integrity over extended periods .

• Short-term Storage: For short-term use, the antibody can be stored at 4°C, which facilitates more frequent access without repeated freeze-thaw cycles .

• Formulation: The antibody is typically supplied at a concentration of 1.0mg/mL in phosphate buffered saline (without Mg²⁺ and Ca²⁺), pH 7.4, containing 150mM NaCl, 0.02% sodium azide, and 50% glycerol . This formulation helps maintain stability during storage.

• Aliquoting: To minimize freeze-thaw cycles, it is advisable to prepare small aliquots of the antibody upon receipt, especially if it will be used for multiple experiments over time.

• Shipping Conditions: Some products may require dry ice shipping, and additional fees may apply for this special handling .

Adhering to these storage and handling guidelines will help ensure consistent performance of the antibody across experiments and maximize its useful lifespan.

What controls should be included when using G3BP1 (Ab-232) Antibody?

Including appropriate controls is crucial for interpreting results obtained with the G3BP1 (Ab-232) antibody. The following controls should be considered:

• Positive Control: Cell lines or tissues known to express G3BP1, such as 293 cells, HeLa cells, or breast carcinoma tissues, which have been used in validation studies .

• Phosphorylation Controls:

  • Phosphatase-treated samples to confirm phospho-specificity

  • Stimulated samples where G3BP1 phosphorylation is induced

  • Inhibitor-treated samples where the pathway leading to G3BP1 phosphorylation is blocked

• Loading Control: Include antibodies against housekeeping proteins (e.g., GAPDH, β-actin) to normalize for total protein loading, especially in western blot applications.

• Secondary Antibody Control: Include a sample without primary antibody to assess potential non-specific binding of the secondary antibody.

• Peptide Competition: If available, include a control where the antibody is pre-incubated with the immunizing phosphopeptide to confirm specificity.

The antibody is known to detect endogenous levels of G3BP1 only when phosphorylated at Serine 232 , making the phosphorylation-state controls particularly important for validating experimental results.

How should I optimize antibody dilution for different applications?

Optimizing antibody dilution is essential for achieving the best signal-to-noise ratio across different applications. Based on validation data, the following dilution ranges are recommended:

• Western Blot (WB):

  • Recommended dilution range: 1:500 - 1:2000

  • Start with 1:1000 and adjust based on signal intensity and background

• Immunohistochemistry (IHC):

  • Recommended dilution range: 1:50 - 1:100

  • For paraffin-embedded tissues, antigen retrieval methods may need to be optimized alongside antibody dilution

• Immunofluorescence (IF):

  • Recommended dilution range: 1:100 - 1:200

  • Cell fixation method (methanol, paraformaldehyde) may influence optimal antibody concentration

• ELISA:

  • Start with manufacturer's recommendations and perform a dilution series to determine optimal concentration

When optimizing, prepare a series of dilutions spanning the recommended range and evaluate based on:

• Signal intensity at the expected molecular weight/location

• Background levels

• Signal-to-noise ratio

• Consistency across replicates

Remember that optimal dilutions may vary depending on sample type, detection system, and experimental conditions. Document successful protocols for future reference and consistency across experiments.