nr6a1b Antibody

What is NR6A1 and what are its primary functions in cellular biology?

NR6A1 (Nuclear Receptor Subfamily 6 Group A Member 1) is a member of the nuclear hormone receptor protein family primarily involved in transcriptional regulation. In humans, the canonical protein has 480 amino acid residues with a molecular mass of 54.4 kDa and is predominantly localized in the nucleus. Up to five different isoforms have been reported for this protein .

NR6A1 functions as a transcriptional regulator involved in neurogenesis, embryonic development, and germ cell development. It binds to DNA as a homodimer, specifically recognizing direct repeats of the DR0 element (AGGTCA), and often functions as a transcriptional repressor. The suppression of Pou5f1 by NR6A1 facilitates the transition from primitive to definitive neural stem cells, indicating its role in creating an environment conducive to neuronal differentiation .

What are the common synonyms and orthologs of NR6A1?

NR6A1 is known by several synonyms in the scientific literature, which can create confusion when searching for relevant antibodies and research materials.

NR6A1 gene orthologs have been reported in multiple species, including mouse, rat, bovine, frog, chimpanzee, and chicken, with high sequence conservation suggesting important evolutionary functions .

How should researchers select the most appropriate NR6A1 antibody for their experiments?

When selecting an NR6A1 antibody for research applications, consider the following critical factors:

• Target region specificity: Determine whether you need an antibody targeting the N-terminal region, C-terminal region, or the ligand-binding domain, depending on your experimental goals. For instance, antibodies targeting the ligand binding domain are available from multiple vendors and show high species cross-reactivity .

• Species reactivity: Evaluate cross-reactivity with your experimental model. Many commercially available antibodies show reactivity across human, mouse, rat, rabbit, dog, pig, cow, horse, monkey, and other species with varying degrees of conservation .

• Application compatibility: Confirm the antibody has been validated for your specific application (Western blot, immunohistochemistry, ELISA, flow cytometry, or immunofluorescence) .

• Clonality consideration: Choose between monoclonal antibodies (for high specificity to a single epitope) or polyclonal antibodies (for broader epitope recognition and potentially stronger signals) .

• Published validation: Review literature citing the specific antibody to verify its performance in similar experimental contexts .

What validation methods should be employed to confirm NR6A1 antibody specificity?

Proper validation of NR6A1 antibodies is crucial for generating reliable research data. Recommended validation methods include:

• Positive and negative control tissues/cell lines: Use tissues or cell lines with known NR6A1 expression levels. For example, HepG2 (human hepatocellular carcinoma) cells show positive NR6A1 staining, while MOLT-4 (human acute lymphoblastic leukemia) cells typically show negative staining .

• Western blot analysis: Verify a single band at the expected molecular weight (approximately 54.4 kDa for the canonical form) .

• Peptide competition assay: Pre-incubate the antibody with the immunizing peptide to confirm signal elimination in positive samples .

• Knockout/knockdown verification: Test antibody in NR6A1 knockout or knockdown models to confirm signal reduction or elimination .

• Chromatin immunoprecipitation (ChIP) validation: For transcription factor antibodies like NR6A1, confirm binding to known target sequences such as the DR0 element (AGGTCA) or NurRE (AGGTCC) binding sites .

How can ChIP-PCR be optimized for studying NR6A1 DNA binding properties?

ChIP-PCR is a powerful technique for investigating NR6A1's DNA binding in vivo. Based on published protocols, the following optimization steps are recommended:

• Cross-linking optimization: Use 1% formaldehyde for 10 minutes followed by quenching with 0.125M glycine to effectively capture DNA-protein interactions while minimizing background .

• DNA fragmentation: Digestion with Micrococcal Nuclease to obtain genomic DNA fragments ranging from 150 to 900 bp provides optimal resolution. Confirm fragment size by gel electrophoresis before proceeding .

• Antibody selection: Use a minimum of 10 μg of validated anti-GCNF/NR6A1 monoclonal antibody. The monoclonal antibody PP-H7921-00 (Perseus Proteomics) has been successfully used in published ChIP experiments .

• Primer design: Design primers flanking known or predicted NR6A1 binding sites. For NurRE element detection, primers surrounding position -544/-537 relative to transcription start sites have proven effective .

• Controls: Include normal rabbit/mouse serum as a negative control and test primers for known NR6A1 target genes as positive controls .

• Quantification: Use quantitative PCR to accurately measure enrichment. A 50-fold increase in NR6A1 expression via transfection has been reported to enhance NR6A1 binding to target regions containing NurRE elements .

How does NR6A1 DNA binding affinity change with mutations, and how can this be assessed?

NR6A1 binding affinity to DNA can be significantly altered by mutations, particularly those in the DNA binding domain or ligand binding domain. This can be assessed using electrophoretic mobility shift assay (EMSA):

• Wild-type vs. mutant comparison: Studies have shown that missense variants like Arg66Cys and Met392Arg in NR6A1 dramatically decrease binding affinity to DR0 DNA sequences compared to native NR6A1 .

• Protein expression verification: When performing binding assays, ensure equivalent expression levels of wild-type and mutant proteins by western blot quantification before conducting binding experiments .

• Competition assays: Verify binding specificity by adding excess unlabeled DR0 probe (125-fold excess has been shown to block complex formation) while confirming that unrelated DNA sequences (like Oct2A-binding oligonucleotides) do not compete .

• Antibody supershift: Confirm the presence of NR6A1 in the protein-DNA complex using anti-tag antibodies (e.g., anti-Myc) which should cause a supershift in the band pattern .

• Correlation with function: Correlate reduced DNA binding with functional consequences, such as altered transcriptional activity measured by luciferase reporter assays .

What roles does NR6A1 play in regulating hypocretin/orexin gene transcription?

NR6A1 has been identified as a key regulator of hypocretin/orexin gene transcription, with important implications for sleep-wake cycle regulation:

• Binding site identification: In silico analysis has identified a DR0 element at position -1350/-1345 and a NurRE (DR0-like motif, AGGTCC) at position -544/-537 relative to the translation start site of the prepro-hypocretin gene. These 18-bp motifs are well-conserved between human and mouse genomes .

• Co-localization evidence: Double immunostaining studies have demonstrated that NR6A1 co-localizes with almost all hypocretin neurons in the murine hypothalamus, with clear nuclear localization confirmed by DAPI co-staining .

• Functional modulation: NR6A1 overexpression studies in SH-SY5Y cells have shown suppression of hypocretin promoter activity, while deletion of the putative NR6A1-binding site counters this effect .

• In vivo confirmation: Electroporation of Nr6a1 in the fetal hypothalamus promotes hypocretin transcription compared to GFP-electroporation controls, confirming NR6A1's regulatory role in vivo .

How does Lnc-Nr6a1 function as a multifunctional RNA scaffold and microRNA host gene?

Lnc-Nr6a1 is a TGF-β-upregulated long non-coding RNA that serves multiple functions, including as a scaffold for protein complex formation and as a microRNA host gene:

• Transcript isoforms: Lnc-Nr6a1 processing generates two abundant polyadenylated isoforms (lnc-Nr6a1-1 and lnc-Nr6a1-2) and a longer non-polyadenylated microprocessor-driven lnc-pri-miRNA containing clustered pre-miR-181a2 and pre-miR-181b2 hairpins .

• Cellular functions: Ectopic expression of lnc-Nr6a1-1 or lnc-Nr6a1-2 isoforms enhances cell migration and invasive capacity, while the expression of both isoforms along with miR-181a2 and miR-181b2 confers anoikis resistance .

• Protein scaffolding role: Lnc-Nr6a1-1 directly binds and acts as a scaffold molecule for the assembly of glycolytic enzymes (ENO1, ALDOA, GAPDH, PKM) along with LDHA, supporting substrate channeling for efficient glycolysis .

• Metabolic impact: Knockout of Lnc-Nr6a1 significantly reduces basal glycolysis and compensatory glycolysis, effects that can be reverted by overexpression of the lnc-Nr6a1-1 isoform .

• Complex formation: Coimmunoprecipitation experiments in UV-crosslinked extracts have demonstrated that lnc-Nr6a1-1 facilitates the formation of a multi-enzymatic glycolytic complex, with markedly lower amounts of immunoprecipitated glycolytic enzymes observed in Lnc-Nr6a1-depleted cells .

What are the most common issues with NR6A1 antibodies in western blotting and how can they be addressed?

Western blotting with NR6A1 antibodies can present several challenges. Here are common issues and solutions:

How should researchers optimize immunofluorescence protocols for NR6A1 detection?

For successful immunofluorescence detection of NR6A1, consider these optimization strategies:

• Fixation method: Use 4% paraformaldehyde in 0.1M phosphate buffer (pH 7.4) for optimal preservation of nuclear antigens and epitope accessibility .

• Antigen retrieval: For formalin-fixed paraffin-embedded tissues, heat-induced epitope retrieval in citrate buffer (pH 6.0) or Tris-EDTA buffer (pH 9.0) may improve antibody binding.

• Antibody dilution: Start with manufacturer-recommended dilutions (e.g., 1:500 for anti-GCNF monoclonal antibody has been effective in published studies) and optimize as needed.

• Secondary antibody selection: Use highly cross-adsorbed secondary antibodies labeled with bright fluorophores (Alexa Fluor series) to minimize cross-reactivity and maximize signal-to-noise ratio.

• Counterstaining: Include DAPI nuclear counterstain to confirm nuclear localization of NR6A1 signal, as demonstrated in published studies .

• Positive and negative controls: Include tissues/cells with known high expression (HepG2) and negative expression (MOLT-4) of NR6A1 as controls .

What are the emerging roles of NR6A1 variants in human pathologies?

Recent research has identified potential roles for NR6A1 variants in human congenital disorders:

• Renal and vertebral defects: Heterozygous loss-of-function variants in NR6A1 have been linked to congenital renal, uterine, and costovertebral defects in humans .

• Mechanistic insights: Missense variants like Arg66Cys and Met392Arg have been shown to significantly decrease NR6A1 binding affinity to DR0 DNA sequences, potentially explaining their pathogenic effects .

• Functional consequences: These variants may prevent normal NR6A1 transcriptional activity, disrupting developmental processes that depend on proper NR6A1 function .

• Research implications: These findings suggest NR6A1 antibodies could be valuable tools for studying the molecular mechanisms underlying these congenital disorders and potentially identifying therapeutic targets.

How can NR6A1 antibodies be applied in single-cell analysis techniques?

As single-cell technologies continue to advance, NR6A1 antibodies present opportunities for detailed analysis of transcription factor dynamics:

• Single-cell ChIP-seq: While technically challenging, optimization of NR6A1 antibodies for single-cell ChIP-seq could reveal cell-to-cell variability in NR6A1 binding patterns and regulatory networks.

• CUT&Tag applications: Cleavage Under Targets and Tagmentation (CUT&Tag) using optimized NR6A1 antibodies could provide higher resolution binding data with lower cell input requirements.

• Spatial transcriptomics integration: Combining NR6A1 immunofluorescence with spatial transcriptomics techniques could correlate NR6A1 localization with gene expression patterns at the tissue level.

• Mass cytometry (CyTOF): Metal-conjugated NR6A1 antibodies could enable simultaneous measurement of NR6A1 with other proteins in single-cell protein profiling.

• Live-cell imaging: Development of non-disruptive antibody-based tags could allow real-time monitoring of NR6A1 dynamics during cellular processes like differentiation.