GRIN2C Antibody

What is GRIN2C and why is it relevant to neuroscience research?

GRIN2C (Glutamate Ionotropic Receptor NMDA Type Subunit 2C) is a protein that functions as a component of NMDA receptor complexes. These receptors are heterotetrameric, ligand-gated ion channels with high calcium permeability and voltage-dependent sensitivity to magnesium . In humans, the canonical GRIN2C protein consists of 1233 amino acid residues with a molecular weight of approximately 134.2 kDa .

GRIN2C is particularly relevant to neuroscience research because it plays critical roles in physiological processes such as learning, memory, and synaptic development . Unlike other NMDAR subunits primarily localized in neurons, GRIN2C is highly expressed in astrocytes, suggesting specialized functions in glial cells . The protein serves as a cellular marker for Gray Matter Chandelier Neurons and has been implicated in several neurological conditions including Alzheimer's disease, Parkinson's disease, and schizophrenia .

What are the common applications for GRIN2C antibodies in research?

GRIN2C antibodies are versatile tools employed in multiple experimental techniques:

• Western Blotting (WB): Used to detect and quantify GRIN2C protein expression in tissue or cell lysates, typically identifying a band at approximately 130-134 kDa .

• Immunohistochemistry (IHC): Applied to visualize the spatial distribution of GRIN2C in tissue sections, particularly useful for studying localization patterns in the cerebellum and other brain regions .

• Immunocytochemistry (ICC): Employed to examine subcellular localization of GRIN2C in cultured cells, including primary neuronal and astrocytic cultures .

• Enzyme-Linked Immunosorbent Assay (ELISA): Used for quantitative detection of GRIN2C levels in biological samples .

• Co-immunoprecipitation: Applied in protein interaction studies to identify binding partners of GRIN2C, such as interactions with 14-3-3 proteins that regulate membrane trafficking .

What are the known synonyms and identifiers for GRIN2C in scientific literature?

When conducting literature searches or selecting antibodies, researchers should be aware of the multiple nomenclatures used to describe GRIN2C:

• NMDAR2C or NR2C (N-methyl D-aspartate receptor subtype 2C)

• GluN2C (Glutamate receptor ionotropic, NMDA 2C)

• Glutamate [NMDA] receptor subunit epsilon-3

• GluN2C(alt_5'UTR_77nt) and GluN2C(alt_5'UTR_87nt) (alternative transcript variants)

The human gene identifier is GRIN2C (Gene ID: 2905), and GRIN2C orthologs have been reported in mouse, rat, bovine, frog, chimpanzee, and chicken species . This diversity of terminology is important to consider when designing search strategies for comprehensive literature reviews on this protein.

What methodological considerations are important when selecting a GRIN2C antibody?

When selecting a GRIN2C antibody for experimental applications, researchers should consider several critical factors:

• Epitope specificity: Determine whether the antibody targets the N-terminal, C-terminal, or internal domains of GRIN2C. For instance, some validated antibodies target amino acids 836-1233 (cytoplasmic C-terminus) of rat GluN2C (accession number Q00961) .

• Host species and clonality: Available options include mouse monoclonal and polyclonal antibodies. Monoclonal antibodies offer higher specificity but may recognize a single epitope, while polyclonal antibodies provide broader epitope recognition but potential cross-reactivity .

• Validated applications: Confirm the antibody has been validated for your specific application (WB, IHC, ICC, etc.). Quality antibodies typically undergo validation through knockout testing and show the expected molecular weight band (~130-134 kDa) in Western blots .

• Species reactivity: Verify cross-reactivity with your experimental model. Many GRIN2C antibodies react with human, mouse, and rat proteins, but reactivity should be confirmed for other species .

• Conjugation options: Consider whether unconjugated antibodies or those conjugated with fluorophores (e.g., FL490, Cy3, Dylight488) are appropriate for your experimental design .

How can researchers validate GRIN2C antibody specificity for their experiments?

Proper validation of GRIN2C antibody specificity is crucial for reliable experimental results. A comprehensive validation approach includes:

• Knockout/knockdown controls: Use tissue/cells from GRIN2C knockout animals or cells treated with GRIN2C siRNA as negative controls. For example, a study demonstrated reduced Grin2c expression in astrocytes following siRNA transfection, confirming antibody specificity .

• Peptide blocking experiments: Pre-incubate the antibody with the immunizing peptide before use in the experiment. Absence of signal in this condition confirms epitope specificity.

• Western blot analysis: Verify that the antibody detects a single band of the expected molecular weight (~130-134 kDa) in tissues known to express GRIN2C, such as cerebellum or spinal cord lysates .

• Multiple antibody approach: Use antibodies from different sources or those targeting different epitopes of GRIN2C to confirm consistent localization patterns.

• Correlation with mRNA expression: Compare protein detection patterns with GRIN2C mRNA expression data using RT-PCR or in situ hybridization to ensure concordance between transcript and protein expression patterns.

What are the optimal fixation and tissue processing methods for GRIN2C immunodetection?

The choice of fixation and tissue processing methods significantly impacts GRIN2C immunodetection:

• Fixation for immunohistochemistry:

  • Paraformaldehyde fixation (4%) for 24-48 hours is commonly used for brain and spinal cord tissues

  • Short fixation times (12-24 hours) may better preserve GRIN2C epitopes

  • Post-fixation antigen retrieval using citrate buffer (pH 6.0) or EDTA buffer (pH 9.0) often enhances detection

• Tissue processing for Western blot:

  • Rapid tissue extraction and flash-freezing in liquid nitrogen preserves protein integrity

  • Lysis buffers containing protease inhibitors, phosphatase inhibitors, and mild detergents (0.5-1% Triton X-100) effectively solubilize membrane-bound GRIN2C

  • Avoid repeated freeze-thaw cycles of protein samples

• Cell fixation for immunocytochemistry:

  • 4% paraformaldehyde for 15-20 minutes at room temperature for cultured astrocytes and neurons

  • Mild permeabilization with 0.1% Triton X-100 for 5-10 minutes to access intracellular epitopes while preserving membrane-associated GRIN2C

  • When studying surface expression, avoid permeabilization during antibody incubation steps

How can GRIN2C antibodies be utilized to study its role in calcium signaling pathways?

GRIN2C antibodies have been instrumental in elucidating the protein's role in calcium signaling, particularly in astrocytes. Methodological approaches include:

• Dual immunolabeling with calcium signaling components: Combining GRIN2C antibodies with antibodies against calcium-dependent proteins such as CaMK2b allows visualization of pathway interactions. Research has shown that Grin2c regulates astrocyte proliferation by modulating Ca²⁺/CaMK2b signaling .

• Functional correlation studies: GRIN2C immunodetection can be paired with calcium imaging techniques (e.g., Fluo4 fluorescence) to correlate protein expression with functional calcium influx. Studies have demonstrated that Grin2c overexpression increases intracellular Ca²⁺ concentration in astrocytes, while Grin2c inhibition via siRNA reduces it .

• Phosphorylation-specific antibodies: Antibodies that recognize phosphorylated forms of GRIN2C or downstream effectors can help map activation states of the calcium signaling pathway. This approach has revealed that Grin2c can activate phosphorylation cycles of cyclic adenosine monophosphate response element-binding protein to regulate cellular activity through CaMK2b activation .

• Subcellular fractionation combined with immunoblotting: This technique allows quantification of GRIN2C in different cellular compartments (membrane vs. cytoplasmic), providing insight into trafficking dynamics related to calcium signaling.

What methods can be employed to investigate GRIN2C variants associated with neurodegenerative diseases?

Recent research has implicated GRIN2C variants in neurodegenerative conditions, particularly Alzheimer's disease. Several methodological approaches using GRIN2C antibodies can help investigate these associations:

• Variant-specific antibodies: When available, antibodies specifically recognizing mutant forms (e.g., the A1072V variant) can differentiate wild-type from disease-associated variants in patient samples .

• Surface expression assays: Combining GRIN2C antibodies with surface biotinylation techniques can quantify the surface/total ratio of GRIN2C variants. This method revealed elevated surface expression of the A1072V mutant, correlating with increased NMDAR currents in neurons .

• Co-immunoprecipitation with trafficking regulators: GRIN2C antibodies can be used to study interactions with trafficking proteins such as 14-3-3. Research demonstrated reduced colocalization between mutant GluN2C and 14-3-3 proteins, suggesting altered membrane trafficking as a pathogenic mechanism .

• Electrophysiology combined with immunocytochemistry: Correlating GRIN2C immunolabeling with patch-clamp recordings provides functional insight into how variants affect channel properties. Primary neurons expressing the A1072V variant showed increased NMDAR-induced currents, suggesting altered glutamatergic transmission .

• Brain region-specific expression analysis: Immunohistochemistry with GRIN2C antibodies can map expression patterns of variants across different brain regions affected in neurodegenerative diseases, potentially revealing selective vulnerability patterns.

How can GRIN2C antibodies help differentiate its expression in neurons versus astrocytes?

GRIN2C exhibits a unique expression pattern with high levels in astrocytes, unlike other NMDAR subunits primarily expressed in neurons. Methodological approaches to differentiate its expression include:

• Dual immunofluorescence labeling: Combining GRIN2C antibodies with cell-type-specific markers such as GFAP (for astrocytes) and NeuN or MAP2 (for neurons) enables precise cellular localization. This approach has confirmed high Grin2c expression in astrocytes around injury areas in spinal cord injury models .

• Cell type-specific isolation followed by immunoblotting: Methods like fluorescence-activated cell sorting (FACS) or magnetic-activated cell sorting (MACS) can isolate specific cell populations from brain tissue, followed by Western blot analysis with GRIN2C antibodies to quantify relative expression levels.

• Primary culture systems: Immunocytochemistry on purified primary neuronal and astrocytic cultures allows direct comparison of GRIN2C expression patterns. Successful isolation protocols for neonatal mouse brain astrocytes have been established for such comparisons .

• In situ proximity ligation assay: This technique can detect GRIN2C interactions with cell-type-specific proteins, providing functional context to expression patterns in different neural cells.

• Quantitative immunohistochemistry: Digital image analysis of immunolabeled tissue sections enables quantification of GRIN2C expression intensity in morphologically identified cell types, allowing statistical comparison between neurons and astrocytes across different brain regions.

What are common issues in GRIN2C antibody-based experiments and how can they be addressed?

Researchers frequently encounter several challenges when working with GRIN2C antibodies:

• Background staining: High background can obscure specific GRIN2C signals, particularly in immunohistochemistry. Solutions include:

  • Optimizing antibody dilution (typically 1:200-1:1000 range)

  • Including additional blocking steps with 5-10% normal serum from the secondary antibody host species

  • Using longer washing steps (at least 3 x 10 minutes) with 0.1-0.3% Tween-20 in PBS

• Inconsistent detection in Western blots: GRIN2C is a membrane protein that can be difficult to extract and transfer efficiently. Recommendations include:

  • Using specialized membrane protein extraction buffers containing 0.5-1% SDS or NP-40

  • Extending transfer time or using lower percentage (7.5-8%) gels for improved transfer of high molecular weight GRIN2C

  • Adding 0.05% SDS to transfer buffer while maintaining methanol concentration to enhance transfer efficiency

• Poor reproducibility between experiments: This may result from batch-to-batch antibody variation or tissue processing differences. Solutions include:

  • Using the same antibody lot across experimental series when possible

  • Including consistent positive controls (e.g., cerebellum tissue) in each experiment

  • Standardizing all steps of tissue processing and immunodetection protocols

• Weak signal in fixed tissues: Fixation can mask GRIN2C epitopes. Consider:

  • Testing multiple antigen retrieval methods (heat-induced vs. enzymatic)

  • Using amplification systems like tyramide signal amplification for low-abundance detection

  • Exploring alternative fixation protocols with shorter fixation times or different fixatives

How can post-translational modifications affect GRIN2C antibody detection?

Post-translational modifications (PTMs) of GRIN2C can significantly impact antibody recognition and experimental outcomes:

• Glycosylation: GRIN2C undergoes glycosylation, which can mask epitopes or alter protein migration in gels . Researchers should consider:

  • Treatment with deglycosylating enzymes (PNGase F) before immunodetection to remove N-linked glycans

  • Using antibodies raised against peptide sequences known to be free from glycosylation sites

  • Comparing apparent molecular weights with and without deglycosylation to assess modification extent

• Phosphorylation: Phosphorylation states may affect epitope accessibility. Approaches include:

  • Using phosphatase inhibitors during tissue/cell lysis to preserve physiological phosphorylation states

  • Comparing antibodies targeting different regions that may be differentially affected by phosphorylation

  • Considering phosphorylation-specific antibodies if studying activity-dependent GRIN2C regulation

• Proteolytic processing: GRIN2C may undergo endogenous proteolytic cleavage, generating fragments that might not be recognized by all antibodies. Strategies include:

  • Using antibodies targeting different domains to detect potential processed fragments

  • Including protease inhibitors during sample preparation

  • Comparing results from different antibodies to verify detection of the same molecular species

What strategies can improve detection of low-abundance GRIN2C in specific cell populations?

GRIN2C expression can be challenging to detect in certain cell types or brain regions. Advanced techniques to enhance detection include:

• Signal amplification methods:

  • Tyramide signal amplification (TSA) can increase detection sensitivity by 10-100 fold for immunohistochemistry

  • Quantum dot-conjugated secondary antibodies provide brighter, more photostable signals for prolonged imaging

  • Poly-HRP detection systems offer enhanced sensitivity for both Western blotting and immunohistochemistry

• Enrichment strategies:

  • Immunoprecipitation before Western blotting can concentrate GRIN2C from dilute samples

  • Subcellular fractionation to isolate membrane fractions can enrich for GRIN2C content

  • Laser capture microdissection combined with sensitive Western blotting can analyze specific cell populations

• Alternative detection platforms:

  • Proximity ligation assay (PLA) can detect single protein molecules with greatly enhanced sensitivity

  • Single-molecule array (Simoa) technology permits detection of proteins at femtomolar concentrations

  • Mass spectrometry-based approaches following immunoprecipitation can identify GRIN2C in complex samples

• Transcriptional manipulation:

  • Temporary overexpression systems can increase protein levels to facilitate detection methods optimization

  • Using regions with known high expression (cerebellum) as positive controls while optimizing protocols for low-expression areas

How are GRIN2C antibodies being utilized in studies of astrocyte function in neurological diseases?

Recent research has revealed exciting new roles for GRIN2C in astrocyte biology with implications for neurological diseases:

• Astrocyte proliferation in spinal cord injury: GRIN2C antibodies have been crucial in demonstrating that decreased Grin2c expression in astrocytes promotes abnormal proliferation after spinal cord injury through inhibition of the Ca²⁺/CaMK2b pathway. The blockade of IL1α using neutralizing antibodies resulted in increased Grin2c expression and inhibition of astrocyte proliferation, suggesting a potential therapeutic approach for reducing glial scarring .

• Calcium signaling dysregulation: Immunohistochemical studies using GRIN2C antibodies, combined with calcium imaging techniques, have revealed that Grin2c regulates intracellular calcium levels in astrocytes. Grin2c-SiRNA transfection decreased calcium signaling in astrocytes while enhancing their proliferative capacity, establishing a mechanistic link between calcium homeostasis and cell cycle regulation .

• Inflammatory mediator interactions: Dual labeling with GRIN2C antibodies and inflammatory cytokine markers has uncovered that IL1α specifically inhibits Grin2c expression in astrocytes, revealing a novel mechanism by which inflammation influences glial cell behavior in neurological conditions .

• Disease-specific expression patterns: Comparative immunohistochemical studies are beginning to map differential GRIN2C expression in astrocytes across various neurological conditions, potentially explaining disease-specific astrocyte responses and identifying targeted intervention points.

What methodological approaches can investigate the relationship between GRIN2C variants and Alzheimer's disease?

Emerging research has identified a rare missense variant in GRIN2C (A1072V) associated with late-onset autosomal dominant Alzheimer's disease. Sophisticated methodological approaches to investigate this relationship include:

• Structure-function studies using mutant-specific antibodies:

  • Site-directed mutagenesis to create GluN2C A1072V in expression systems

  • Comparing surface/total ratio of wild-type versus mutant GluN2C using quantitative immunocytochemistry

  • Analyzing colocalization patterns with 14-3-3 proteins that regulate trafficking

• Electrophysiological correlation with protein expression:

  • Patch-clamp recordings from neurons expressing mutant GluN2C to measure NMDAR currents

  • Correlating current magnitudes with immunocytochemically determined surface expression levels

  • Investigating calcium influx patterns using calcium imaging in parallel with GRIN2C immunodetection

• Development of cellular models:

  • Creation of patient-derived induced pluripotent stem cells (iPSCs) carrying the GRIN2C variant

  • Differentiation into neurons and astrocytes followed by immunocytochemical characterization

  • Comparison of GRIN2C expression, localization, and function between patient and control cells

• Animal model development:

  • Generation of knock-in mice expressing the A1072V variant

  • Comprehensive immunohistochemical mapping of GluN2C distribution across brain regions

  • Correlation of expression patterns with behavioral, electrophysiological, and pathological outcomes

How can multiplex imaging with GRIN2C antibodies advance understanding of NMDA receptor composition in health and disease?

Advanced multiplex imaging approaches using GRIN2C antibodies are providing unprecedented insights into NMDA receptor composition:

• Multiplexed immunofluorescence techniques:

  • Sequential multiplexing allows detection of GRIN2C alongside other NMDAR subunits (GluN1, GluN2A, GluN2B, GluN2D) to map receptor heterogeneity

  • Tyramide signal amplification combined with antibody stripping enables detection of 5-7 proteins on the same tissue section

  • Spectral unmixing microscopy can distinguish closely overlapping fluorophores for cleaner multicolor imaging

• Super-resolution microscopy applications:

  • Stimulated emission depletion (STED) microscopy provides 30-80 nm resolution of GRIN2C distribution

  • Single-molecule localization microscopy (STORM/PALM) enables visualization of individual GRIN2C-containing receptors

  • Expansion microscopy physically enlarges specimens to improve resolution of conventional microscopes

• Proximity-based detection methods:

  • Förster resonance energy transfer (FRET) microscopy can detect nanoscale interactions between GRIN2C and other proteins

  • Proximity ligation assay (PLA) visualizes protein-protein interactions within 40 nm, ideal for studying NMDAR subunit associations

  • APEX2 proximity labeling combined with proteomics can identify the GRIN2C interactome in specific cellular compartments

• Tissue clearing techniques:

  • CLARITY, iDISCO+, and other clearing methods enable whole-brain imaging of GRIN2C distribution

  • Light-sheet microscopy of cleared tissues provides rapid 3D imaging of GRIN2C across entire neural circuits

  • Quantitative analysis of clearing-compatible immunolabeling allows comparison of GRIN2C expression in health versus disease models