DLGAP3 Antibody

What is DLGAP3 and why is it an important research target?

DLGAP3 (Discs Large Homolog Associated Protein 3), also known as SAPAP3, is a post-synaptic scaffolding protein that specifically interacts with PSD-95/SAP90, a membrane-associated guanylate kinase localized at postsynaptic density in neuronal cells. It functions as an adaptor protein that interacts with various synaptic scaffolding proteins, cytoskeletal components, and signaling molecules including focal adhesion kinase (FAK) and proline-rich tyrosine kinase 2 (PYK2) .

Unlike other SAPAP family members, both DLGAP3 protein and mRNA are targeted to dendrites, while SAPAP1, -2, and -4 mRNAs are primarily detected in cell bodies . This unique localization pattern makes DLGAP3 particularly interesting for studying dendritic functions and synaptic organization.

Research significance:

• Primary role in molecular organization of synapses and neuronal cell signaling

• Implicated in obsessive-compulsive disorder (OCD) and related conditions

• Recently identified as a potential tumor suppressor in gliomas

• Critical component in the regulation of glutamatergic synapses in the striatum

Which applications are DLGAP3 antibodies validated for?

According to multiple manufacturer validations, DLGAP3 antibodies have been successfully used in:

Positive detection has been consistently demonstrated in:

• Human brain tissue

• Mouse brain tissue

• Human stomach tissue (for IHC)

What is the typical molecular weight observed for DLGAP3 in Western blots?

The observed molecular weight of DLGAP3 can vary slightly depending on experimental conditions and tissue source:

• Calculated molecular weight: 106 kDa

• Observed molecular weight: 106-120 kDa or 110 kDa

Researchers should note that the actual observed band may not always match the calculated weight exactly. This discrepancy is often due to post-translational modifications or tissue-specific isoforms. As explained by one manufacturer: "The mobility is affected by many factors, which may cause the observed band size to be inconsistent with the expected size. If a protein in a sample has different modified forms at the same time, multiple bands may be detected on the membrane."

How should I design experiments to ensure specificity when using DLGAP3 antibodies?

To ensure specificity when working with DLGAP3 antibodies:

• Select validated antibodies: Choose antibodies specifically tested for cross-reactivity with other DLGAP family members. For example, some commercially available antibodies have been verified to "have no cross reaction to other DLGAP members" .

• Include proper controls:

  • Positive controls: Human or mouse brain tissue consistently shows reliable detection

  • Negative controls: Tissues known not to express DLGAP3 or DLGAP3 knockout/knockdown samples

  • Cross-reactivity controls: If available, test against other DLGAP family members

• Validation approaches:

  • Western blotting for molecular weight verification

  • Knockdown/knockout validation: Some antibodies have been validated in KD/KO experiments

  • Orthogonal validation: Some manufacturers conduct RNAseq validation

• Technical considerations:

  • For IHC: "Suggested antigen retrieval with TE buffer pH 9.0; alternatively, antigen retrieval may be performed with citrate buffer pH 6.0"

  • For WB: Use freshly prepared tissue samples, particularly from brain

  • For IF: Optimized fixation protocols for neuronal samples

What are the recommended storage and handling conditions for DLGAP3 antibodies?

Based on manufacturer recommendations across multiple sources:

For optimal performance:

• Store immediately upon receipt at the recommended temperature

• Avoid repeated freeze/thaw cycles when possible

• Smaller sized products (e.g., 20μl) may contain 0.1% BSA as a stabilizer

How has DLGAP3 antibody been used to study neuropsychiatric disorders?

DLGAP3 has emerged as an important research target in neuropsychiatric disorders, particularly obsessive-compulsive disorder (OCD) and related conditions:

• Animal model studies: DLGAP3/SAPAP3 knockout mice exhibit OCD-like symptoms, specifically excessive self-grooming behaviors. Research has shown that "mice lacking SAPAP3 exhibited OCD-like symptoms which could be relieved by lentiviral-mediated selective expression of SAPAP3 in the striatum of SAPAP3-mutant mice" .

• Genetic association studies: Family-based genetic association studies have examined DLGAP3 as a candidate gene in Tourette Syndrome (TS), which shares familial relationships with OCD and grooming disorders. For example, one study found "nominally significant associations were identified between TS and rs11264126 and two haplotypes containing rs11264126 and rs12141243" .

• Human studies methodology:

  • Researchers have used DLGAP3 antibodies to examine protein expression in patient samples

  • In genetic studies, tag SNPs have been selected to capture common alleles in the DLGAP3 region

  • Family-based samples (e.g., trios) have been used to minimize population stratification effects

• Biochemical analysis: DLGAP3 antibodies have been used to demonstrate that "SAPAP3-deficient mice (SAPAP3−/−) were also found to have cortico-striatal synaptic deficits" , helping establish the neurobiological basis of the observed behavioral abnormalities.

The antibodies serve as critical tools for validating genetic findings at the protein level and for characterizing the molecular consequences of genetic variants in both animal models and human samples.

What recent discoveries have been made about DLGAP3's role in cancer biology?

Recent research has uncovered an unexpected role for DLGAP3 in cancer biology, particularly in gliomas:

A February 2025 study demonstrated that "DLGAP3 is a potential tumor suppressor and valuable prognostic biomarker in gliomas" . Key findings from this research include:

• Expression pattern: DLGAP3 was found to be "low expressed in gliomas, and decreased DLGAP3 expression was strongly correlated with poor survival of glioma patients" .

• Functional effects:

  • "Ectopic expression of DLGAP3 in glioma cell lines dramatically inhibited cell proliferation, invasion and migration"

  • These findings establish DLGAP3 as a potential tumor suppressor in gliomas

• Molecular mechanism: DLGAP3 appears to inhibit glioma tumorigenesis through:

  • Binding to RGS12 protein

  • Increasing RGS12 expression

  • Inhibiting phosphorylation of MEK and ERK

  • Reducing BRAF transcription and translation

  • Ultimately decreasing activity of the MAPK/ERK signaling pathway

• Methodological approaches:

  • Western blot analysis using DLGAP3 antibodies

  • Co-immunoprecipitation to establish protein interactions

  • Enrichment analysis

  • Dual-luciferase reporter system assays

This research opens new avenues for using DLGAP3 antibodies in cancer research, beyond their traditional applications in neuroscience.

What are common challenges when using DLGAP3 antibodies and how can they be addressed?

Based on manufacturer information and research applications, common challenges with DLGAP3 antibodies include:

• Inconsistent band sizes in Western blot:

  • Challenge: Observed molecular weight (106-120 kDa or 110 kDa) may differ from calculated weight (106 kDa)

  • Solution: "Western blotting is a method for detecting a certain protein in a complex sample based on the specific binding of antigen and antibody. Different proteins can be divided into bands based on different mobility rates. The mobility is affected by many factors, which may cause the observed band size to be inconsistent with the expected size." Consider post-translational modifications, tissue-specific isoforms, and validate with positive controls.

• Tissue specificity considerations:

  • Challenge: DLGAP3 expression is primarily in neuronal tissues, making detection in other tissues difficult

  • Solution: Focus on validated sample types (human/mouse brain tissue) . For non-neuronal tissues, increase antibody concentration and optimize detection methods.

• Antigen retrieval for IHC:

  • Challenge: Suboptimal antigen retrieval can lead to weak or absent signal

  • Solution: Use recommended protocols: "suggested antigen retrieval with TE buffer pH 9.0; alternatively, antigen retrieval may be performed with citrate buffer pH 6.0"

• Buffer and storage issues:

  • Challenge: Antibody degradation affecting performance

  • Solution: Store at -20°C, avoid freeze/thaw cycles, and use manufacturer-recommended buffers (typically PBS with 0.02% sodium azide and 50% glycerol, pH 7.3)

• Validation in knockdown/knockout models:

  • Challenge: Confirming antibody specificity

  • Solution: When available, use DLGAP3 knockdown or knockout samples to confirm specificity. Some antibodies have been specifically validated in KD/KO applications .

How should I interpret DLGAP3 localization patterns in neuronal samples?

When interpreting DLGAP3 localization patterns in neuronal samples:

• Expected subcellular localization:

  • DLGAP3 is primarily localized to "cholinergic synapse, glutamatergic synapse, neuromuscular junction, plasma membrane, postsynaptic density, postsynaptic specialization"

  • Unlike other family members, "both DLGAP3 protein and mRNA are targeted to dendrites, whereas SAPAP1, -2, and -4 mRNAs are detected mainly in cell bodies"

• Co-localization markers:

  • DLGAP3 should co-localize with PSD-95/SAP90 at postsynaptic densities

  • Expected to show punctate staining patterns along dendrites

  • May co-localize with other postsynaptic proteins like glutamate receptors

• Isoform considerations:

  • "At least two isoforms are known to exist" , which may show slightly different localization patterns

  • Consider using isoform-specific antibodies when available

• Developmental and activity-dependent changes:

  • DLGAP3 expression and localization may change during development

  • Synaptic activity may influence its distribution and abundance

• Pathological conditions:

  • In disease models (OCD, Tourette's), distribution patterns may be altered

  • In gliomas, expression is reduced compared to normal brain tissue

How are DLGAP3 antibodies being used in cutting-edge research?

DLGAP3 antibodies are being utilized in several cutting-edge research areas:

• Glioma tumor suppression mechanisms:

  • Recent findings (February 2025) demonstrate that "DLGAP3 is a potential tumor suppressor and valuable prognostic biomarker in gliomas"

  • Researchers used DLGAP3 antibodies to demonstrate that "ectopic expression of DLGAP3 in glioma cell lines dramatically inhibited cell proliferation, invasion and migration"

  • The antibodies helped establish that DLGAP3 "can tightly connected with RGS12" and that "DLGAP3 overexpression significantly increased the expression of RGS12 and inhibited the phosphorylation levels of MEK and ERK"

• Neuropsychiatric disorder mechanisms:

  • Ongoing research into the molecular mechanisms underlying OCD, Tourette Syndrome, and related conditions

  • Family-based genetic association studies have found "nominally significant associations between TS and rs11264126 and two haplotypes containing rs11264126 and rs12141243" , with DLGAP3 antibodies being crucial for validating these genetic findings at the protein level

• Synaptic plasticity regulation:

  • DLGAP3's interaction with "different synaptic scaffolding proteins, cytoskeletal and signaling components, such as focal adhesion kinase (FAK) and proline-rich tyrosine kinase 2 (PYK2)" continues to be an active area of research

  • Antibodies are crucial for mapping these protein interactions through co-immunoprecipitation and other techniques

• Therapeutic target validation:

  • Studies building on the finding that OCD-like symptoms in SAPAP3-knockout mice "could be relieved by lentiviral-mediated selective expression of SAPAP3 in the striatum"

  • DLGAP3 antibodies are essential for confirming protein expression in these therapeutic interventions

What advances in DLGAP3 antibody technology are improving research capabilities?

Recent advances in DLGAP3 antibody technology are enhancing research capabilities:

• Enhanced validation methodologies:

  • Orthogonal RNAseq validation: Some manufacturers now employ this approach to ensure antibody specificity

  • Knockout/knockdown validation: Increasing availability of antibodies validated in KD/KO models

• Application-specific optimization:

  • Buffer formulations optimized for specific applications

  • Detailed protocols for antigen retrieval: "suggested antigen retrieval with TE buffer pH 9.0; alternatively, antigen retrieval may be performed with citrate buffer pH 6.0"

• Cross-reactivity testing:

  • Rigorous testing against other DLGAP family members: "The antibody has no cross reaction to other DLGAP members"

  • Testing against recombinant protein arrays: "Protein array of 364 human recombinant protein fragments"

• Comprehensive tissue profiling:

  • Extensive validation across tissue arrays: "IHC tissue array of 44 normal human tissues and 20 of the most common cancer type tissues"

  • Integration with The Human Protein Atlas project data

• Species reactivity characterization:

  • Detailed validation across species (human, mouse, rat) enabling comparative studies

  • Documented differences in molecular weight and expression patterns between species

These technological advances allow researchers to have greater confidence in their experimental results and expand the range of applications for DLGAP3 antibodies in both neuroscience and cancer research.