NHLRC1 Antibody

What is NHLRC1 and what is its biological function?

NHLRC1 (NHL repeat containing 1), also known as Malin or EPM2B, is a single subunit E3 ubiquitin-protein ligase that plays a critical role in suppressing cellular toxicity of misfolded proteins. It promotes protein degradation through the ubiquitin-proteasome system (UPS). The protein contains a zinc-binding RING finger domain and six NHL-repeat domains, with a calculated molecular weight of 42 kDa and observed molecular weight of 45-47 kDa in western blot applications . Defects in NHLRC1 are causally linked to progressive myoclonic epilepsy type 2 (EPM2) . Recent research has identified NHLRC1 as a novel AKT activator in lung cancer, suggesting its potential role in oncogenesis through regulation of cell survival signaling pathways .

What applications are commonly used for NHLRC1 antibodies in research?

NHLRC1 antibodies are validated for several key research applications:

These applications enable researchers to detect, quantify, and localize NHLRC1 protein in various experimental systems, facilitating studies on its expression, regulation, and function in normal and disease states.

What are the optimal dilutions and conditions for using NHLRC1 antibodies?

The optimal working conditions for NHLRC1 antibodies vary by application and specific antibody clone:

For immunohistochemistry with 21310-1-AP antibody, antigen retrieval with TE buffer pH 9.0 is suggested, with citrate buffer pH 6.0 as an alternative . It is essential to titrate the antibody in each specific experimental system to determine optimal conditions, as results may be sample-dependent .

How should I design experiments to investigate NHLRC1's role in AKT signaling?

Based on recent findings identifying NHLRC1 as an AKT activator, the following experimental approach is recommended:

• NHLRC1 knockdown experiments:

  • Use siRNA pools targeting NHLRC1 in appropriate cell lines (A549 and H1299 lung cancer cells have been validated)

  • Transfect using RNAiMAX reagent according to manufacturer's protocol

  • Include negative control siRNA pools

  • Verify knockdown efficiency by western blot and/or qRT-PCR

• NHLRC1 overexpression experiments:

  • Clone NHLRC1 coding region into an expression vector (pCRII-cGFP backbone has been validated)

  • Generate C26S catalytic mutant using site-directed mutagenesis for comparison to wild-type

  • Verify sequence by Sanger sequencing

  • Transfect cells (H1299 cells have been validated) using Lipofectamine3000

  • Include empty vector controls

• Analysis of AKT activation:

  • Assess phosphorylated AKT at serine 473 (pAKT Ser473) by western blot

  • Calculate ratio of total AKT to pAKT Ser473

  • Include pathway controls (e.g., treat with 50 μM LY294002 PI3K inhibitor for 1 hour prior to protein isolation)

• Functional assays:

  • Transwell migration and invasion assays to assess cellular phenotypes

  • Proliferation assays to evaluate growth effects

  • Analyze data using two-sided paired Student's t-test with a confidence interval of 0.95

This experimental design allows for comprehensive investigation of how NHLRC1 modulates AKT signaling and its downstream functional consequences.

What methods are available to study NHLRC1 epigenetic regulation?

The epigenetic regulation of NHLRC1 can be investigated using these methodological approaches:

• DNA methylation analysis:

  • Sequence-specific methylation-sensitive mass spectrometry (MassARRAY) can quantitatively determine DNA methylation of regions surrounding NHLRC1

  • Analyze the differentially methylated region (DMR) upstream of NHLRC1 containing specific CpG sites (e.g., cg06646708)

  • Pyrosequencing can be used for targeted methylation analysis of specific regions

• Histone modification analysis:

  • ChIP-seq to assess activating histone marks (H3K4me1, H3K4me3, H3K27ac) and repressive marks (H3K27me3)

  • Compare histone modification patterns between cancer and normal cell lines (A549 lung cancer vs. NHLF normal lung fibroblasts have been validated)

• Experimental manipulation of DNA methylation:

  • Treat cells with 5-Aza-2′-deoxycytidine (DAC) at optimized concentrations (10-1000 nM)

  • Determine treatment efficacy by measuring global DNA methylation of long-interspersed elements (LINE1) by pyrosequencing

  • Analyze methylation changes in the NHLRC1 DMR after treatment

  • Assess corresponding changes in NHLRC1 expression by qRT-PCR

• Correlation with gene expression:

  • Real-time PCR to quantify NHLRC1 mRNA levels

  • Western blot to assess protein expression

  • Correlate methylation levels with expression data

These methods provide a comprehensive approach to understanding how epigenetic mechanisms regulate NHLRC1 expression in normal and disease contexts.

How does NHLRC1 function in the ubiquitin-proteasome system?

NHLRC1 functions as an E3 ubiquitin ligase within the ubiquitin-proteasome system (UPS), playing a crucial role in protein quality control:

• Structural and functional domains:

  • Contains a zinc-binding RING finger domain essential for E2 enzyme interaction and ubiquitin transfer

  • Features six NHL-repeat domains likely involved in substrate recognition

  • The C26S mutation disrupts catalytic activity, as demonstrated in overexpression studies

• Cellular function:

  • Suppresses cellular toxicity of misfolded proteins by promoting their degradation through the UPS

  • The enzymatic activity depends on the integrity of its catalytic domain, as the C26S mutant fails to activate AKT signaling in contrast to wild-type NHLRC1

• Experimental evidence:

  • NHLRC1 knockdown affects cellular processes regulated by protein homeostasis

  • Wild-type NHLRC1 overexpression, but not the C26S catalytic mutant, leads to AKT pathway activation

  • NHLRC1 defects are associated with progressive myoclonic epilepsy type 2, suggesting essential roles in neuronal protein homeostasis

Understanding NHLRC1's function in the UPS provides insights into how its dysregulation contributes to disease pathogenesis and identifies potential therapeutic targets for conditions characterized by aberrant protein quality control.

What is the significance of NHLRC1 as a potential biomarker in lung cancer?

Recent research has identified NHLRC1 as a promising biomarker in lung cancer with significant implications for diagnosis, prognosis, and therapeutic targeting:

• Differential expression and regulation:

  • NHLRC1 expression is increased by 5.4-fold in adenocarcinoma and 3.6-fold in squamous cell carcinoma compared to adjacent normal tissue

  • This overexpression correlates with hypomethylation of a differentially methylated region (DMR) upstream of the NHLRC1 gene

  • Histone modification patterns (enrichment of H3K4me1, H3K4me3, H3K27ac) support enhanced transcriptional activity in cancer cells

• Functional role in oncogenic signaling:

  • NHLRC1 functions as a novel AKT activator, regulating phosphorylation at serine 473

  • Knockdown of NHLRC1 attenuates oncogenic PI3K-AKT-mTORC2 signaling

  • Wild-type NHLRC1 overexpression (but not catalytic mutant C26S) upregulates pAKT Ser473 by 2-fold

• Potential as a prognostic and therapeutic target:

  • NHLRC1 holds promise as a prognostic biomarker for lung cancer survival and prognosis

  • Its role in AKT activation suggests potential as a therapeutic target

  • Epigenetic regulation of NHLRC1 indicates possibilities for epigenetic therapies to modulate its expression

• Detection methods for clinical applications:

  • DNA methylation analysis of the NHLRC1 DMR using MassARRAY

  • Real-time PCR for mRNA quantification

  • Immunohistochemistry with NHLRC1 antibodies for protein detection in tissue samples

These findings highlight NHLRC1 as a valuable biomarker with significant implications for understanding lung cancer biology and developing new therapeutic strategies.

What are the key technical challenges when using NHLRC1 antibodies?

Researchers may encounter several technical challenges when working with NHLRC1 antibodies:

• Molecular weight considerations:

  • The calculated molecular weight of NHLRC1 is 42 kDa (395 amino acids)

  • Observed molecular weight in western blot is typically 45-47 kDa or 42/45 kDa

  • This discrepancy may reflect post-translational modifications

  • Always include positive controls to confirm proper band identification

• Species reactivity limitations:

  • The 21310-1-AP antibody shows reactivity with human samples

  • The Abbexa NHLRC1 antibody demonstrates broader reactivity with human, mouse, and rat samples

  • Verify antibody compatibility with your experimental model system

• Application-specific recommendations:

  • For IHC with 21310-1-AP, antigen retrieval with TE buffer pH 9.0 is suggested (citrate buffer pH 6.0 as alternative)

  • For western blot, protein transfer efficiency and antibody concentration may need optimization

  • Sample-dependent results require titration in each testing system

• Storage and stability:

  • Store at -20°C for up to one year after shipment

  • The 21310-1-AP antibody is provided in PBS with 0.02% sodium azide and 50% glycerol (pH 7.3)

  • Small sizes (20μl) of 21310-1-AP contain 0.1% BSA

  • Avoid repeated freeze-thaw cycles for optimal antibody performance

Addressing these technical considerations will help ensure reliable and reproducible results when using NHLRC1 antibodies in research applications.

How can I verify NHLRC1 antibody specificity in my experimental system?

Verifying antibody specificity is crucial for obtaining reliable data. For NHLRC1 antibodies, consider these validation approaches:

• Genetic knockdown/knockout controls:

  • Perform siRNA knockdown of NHLRC1 as a negative control

  • CRISPR/Cas9-mediated knockout cells provide an excellent specificity control

  • Compare signal intensity between control and knockdown/knockout samples

• Overexpression controls:

  • Transiently overexpress NHLRC1 in appropriate cell lines

  • Include both wild-type and catalytic mutant (C26S) constructs

  • Observe increased signal intensity in overexpressing cells

• Application-specific validation:

  • For western blot, verify the observed molecular weight (45-47 kDa)

  • For IHC, confirm positive staining in known positive tissues (human heart and brain tissue)

  • Include negative controls (primary antibody omission, isotype controls)

• Cross-validation with multiple antibodies:

  • Compare results using antibodies targeting different epitopes of NHLRC1

  • Consistent results across different antibodies increase confidence in specificity

• Peptide competition assays:

  • Pre-incubate antibody with excess immunizing peptide/protein

  • Specific signal should be blocked or significantly reduced

These validation strategies ensure that experimental observations are genuinely attributable to NHLRC1 rather than non-specific antibody interactions, enhancing data reliability and interpretation.

How can NHLRC1 antibodies contribute to understanding progressive myoclonic epilepsy type 2?

NHLRC1 antibodies provide valuable tools for investigating progressive myoclonic epilepsy type 2 (EPM2), also known as Lafora disease, which is caused by mutations in the NHLRC1 gene:

• Detection of mutant NHLRC1 proteins:

  • Western blot analysis can assess expression levels of wild-type versus mutant NHLRC1 in patient-derived samples

  • Immunohistochemistry can evaluate NHLRC1 distribution patterns in brain tissue samples

  • Comparison of subcellular localization between wild-type and disease-associated variants

• Characterization of pathological mechanisms:

  • Investigation of NHLRC1 interaction with disease-relevant proteins

  • Assessment of ubiquitination activity of wild-type versus mutant NHLRC1

  • Evaluation of protein quality control pathway disruptions

  • Analysis of Lafora body formation in relation to NHLRC1 dysfunction

• Therapeutic development:

  • Screening compounds that may restore NHLRC1 function

  • Monitoring changes in NHLRC1 expression or activity in response to treatment

  • Evaluation of gene therapy approaches targeting NHLRC1

• Biomarker identification:

  • Quantitative assessment of NHLRC1 levels in accessible patient samples

  • Correlation of NHLRC1 expression with disease progression

  • Development of diagnostic tools based on NHLRC1 detection

These approaches can provide crucial insights into the pathophysiology of EPM2 and potentially identify therapeutic targets for this devastating neurological disorder.

What methods can be used to investigate NHLRC1's role in AKT-mediated cancer progression?

To investigate NHLRC1's role in AKT-mediated cancer progression, researchers can employ these methodological approaches:

• Expression and correlation analysis:

  • Quantify NHLRC1 expression in tumor versus normal tissue using real-time PCR and western blot

  • Analyze correlation between NHLRC1 expression and AKT activation (pAKT Ser473 levels)

  • Examine association between NHLRC1 levels and clinical outcomes (survival, metastasis)

• Mechanistic investigation through genetic manipulation:

  • Knockdown NHLRC1 using siRNA pools and assess effects on pAKT Ser473 levels

  • Overexpress wild-type NHLRC1 versus C26S catalytic mutant to evaluate AKT activation

  • Combine with PI3K inhibitors (e.g., LY294002) to confirm pathway specificity

• Functional assays:

  • Perform migration and invasion assays in NHLRC1-modified cells using transwell membrane chambers

  • Assess proliferation rates in relation to NHLRC1 expression levels

  • Evaluate anchorage-independent growth capacity

  • Test sensitivity to AKT pathway inhibitors in cells with altered NHLRC1 expression

• In vivo studies:

  • Generate xenograft models with NHLRC1 knockdown or overexpression

  • Assess tumor growth, invasion, and metastatic potential

  • Analyze AKT activation status in tumor tissues

  • Test therapeutic strategies targeting the NHLRC1-AKT axis

• Epigenetic regulation analysis:

  • Examine NHLRC1 promoter methylation status in tumor samples

  • Correlate methylation patterns with expression levels and AKT activation

  • Test epigenetic drugs for their impact on NHLRC1 expression and cancer cell phenotypes

These approaches provide a comprehensive framework for understanding how NHLRC1 contributes to cancer progression through AKT pathway activation, potentially identifying new therapeutic opportunities.

How is NHLRC1 involved in epigenetic regulation mechanisms?

Recent findings reveal complex relationships between NHLRC1 and epigenetic regulatory mechanisms:

• DNA methylation patterns:

  • A differentially methylated region (DMR) upstream of NHLRC1 shows hypomethylation in lung tumors compared to adjacent normal tissue

  • This hypomethylation correlates with increased NHLRC1 expression (5.4-fold in adenocarcinoma, 3.6-fold in squamous cell carcinoma)

  • MassARRAY analysis confirmed hypomethylation of a 256 bp region upstream of NHLRC1 containing cg06646708

• Histone modification landscape:

  • ChIP-seq data shows enrichment of activating histone marks (H3K4me1, H3K4me3, H3K27ac) in lung cancer cell lines compared to normal lung fibroblasts

  • The repressive mark H3K27me3 is absent in both cancer and normal cells

  • This pattern of histone modifications supports enhanced transcriptional activity of NHLRC1 in cancer cells

• Experimental validation:

  • Treatment with 5-Aza-2′-deoxycytidine (DAC), a DNA methyltransferase inhibitor, leads to decreased methylation of the NHLRC1 DMR

  • Global DNA demethylation correlates with increased NHLRC1 expression

  • Baseline NHLRC1 expression in lung tumor cells is approximately 2-fold higher compared to normal bronchial cells

• Methodological approaches:

  • Methylation-sensitive mass spectrometry for DNA methylation analysis

  • Real-time PCR for gene expression quantification

  • Pyrosequencing for global DNA methylation assessment (LINE1 elements)

  • ChIP-seq for histone modification profiling

These findings highlight the importance of epigenetic mechanisms in regulating NHLRC1 expression and suggest potential therapeutic strategies targeting these regulatory pathways.

What is the relationship between NHLRC1 and the PI3K-AKT-mTOR signaling pathway?

Research has revealed NHLRC1 as a novel regulator of the PI3K-AKT-mTOR signaling pathway with significant implications for cellular homeostasis and disease:

• AKT activation:

  • NHLRC1 knockdown results in downregulation of phosphorylated AKT at serine 473 (pAKT Ser473) in lung cancer cell lines

  • The ratio of total AKT to pAKT Ser473 shifts from approximately 1:1 in control cells to 1:2 or 1:3 in NHLRC1 siRNA-treated cells

  • This indicates that NHLRC1 loss alone is sufficient to attenuate oncogenic PI3K-AKT-mTORC2 signaling

• Functional dependency on E3 ligase activity:

  • Transient overexpression of wild-type NHLRC1 in H1299 cells results in 2-fold upregulation of pAKT Ser473

  • In contrast, overexpression of an NHLRC1-C26S catalytic mutant does not induce this upregulation

  • This suggests that NHLRC1's E3 ubiquitin ligase activity is required for AKT activation

• Pathway integration:

  • NHLRC1-mediated AKT activation is dependent on upstream PI3K signaling, as PI3K inhibitor treatment attenuates pAKT Ser473 levels even in cells overexpressing NHLRC1

  • This places NHLRC1 as an intermediate regulator within the PI3K-AKT pathway

• Methodological approaches:

  • Western blot analysis using phospho-specific antibodies to detect pAKT Ser473

  • Genetic manipulation through siRNA knockdown and overexpression

  • Pharmacological intervention using pathway-specific inhibitors (e.g., LY294002 PI3K inhibitor)

  • Functional assays to assess downstream consequences of altered signaling

Understanding this relationship provides insights into how NHLRC1 contributes to cellular signaling networks and identifies potential therapeutic targets for diseases characterized by dysregulated PI3K-AKT-mTOR signaling.

What are the current limitations in NHLRC1 antibody research?

Despite significant advances in NHLRC1 antibody applications, several limitations remain:

• Technical constraints:

  • Limited availability of antibodies that work across multiple applications and species

  • Current antibodies show variable species reactivity (some limited to human samples)

  • Discrepancies between calculated (42 kDa) and observed molecular weights (45-47 kDa) may complicate data interpretation

• Biological understanding gaps:

  • Incomplete characterization of NHLRC1 post-translational modifications

  • Limited knowledge of tissue-specific expression patterns beyond heart and brain

  • Incomplete catalog of NHLRC1 substrates and binding partners

• Methodological challenges:

  • Need for standardized protocols across research groups

  • Optimization requirements for specific applications (e.g., antigen retrieval methods for IHC)

  • Variability in results across different cell lines and tissue types

• Translation to clinical applications:

  • Limited validation of NHLRC1 as a biomarker in diverse patient cohorts

  • Need for standardized assessment methods for potential clinical use

  • Incomplete understanding of NHLRC1 alterations across different disease states

Addressing these limitations will require continued development of more specific antibodies, standardized protocols, and comprehensive characterization of NHLRC1 biology across different experimental systems and disease contexts.

What future directions should researchers explore with NHLRC1 antibodies?

Based on current knowledge and technological capabilities, several promising research directions for NHLRC1 antibodies include:

• Expanded disease applications:

  • Investigate NHLRC1's role beyond epilepsy and lung cancer in other neurological disorders and cancer types

  • Explore potential connections to metabolic diseases given NHLRC1's role in protein quality control

  • Assess NHLRC1 as a biomarker in a broader range of pathological conditions

• Advanced technological approaches:

  • Develop phospho-specific antibodies to detect post-translational modifications of NHLRC1

  • Apply super-resolution microscopy to elucidate NHLRC1's subcellular localization with higher precision

  • Implement multiplexed antibody techniques to study NHLRC1 in complex signaling networks

• Therapeutic targeting strategies:

  • Use antibodies to screen small molecule libraries for compounds that modulate NHLRC1 activity

  • Develop antibody-drug conjugates targeting NHLRC1 in cancers where it is overexpressed

  • Explore antibody-based approaches for monitoring therapeutic responses

• Integrative biology approaches:

  • Combine antibody-based detection with multi-omics data to understand NHLRC1 in system-wide contexts

  • Correlate NHLRC1 protein levels with epigenetic modifications and transcriptional changes

  • Utilize spatial transcriptomics and proteomics to map NHLRC1 distribution in tissues with high resolution

• Structural biology integration:

  • Use antibodies as tools to purify NHLRC1 for structural studies

  • Develop conformation-specific antibodies to detect different functional states

  • Investigate structure-function relationships of NHLRC1 domains