RNASEH2A Antibody

What is RNASEH2A and what is its role in cellular function?

RNASEH2A is the catalytic subunit of RNase HII, an endonuclease that specifically degrades the RNA of RNA:DNA hybrids. In humans, the canonical protein has a length of 299 amino acid residues and a mass of 33.4 kDa, with subcellular localization in the nucleus . As a member of the RNase HII protein family, RNASEH2A functions as the catalytic component of a heterotrimer complex that includes RNASEH2B and RNASEH2C subunits . This complex plays a critical role in the removal of ribonucleotides misincorporated in genomic DNA and is considered the major nuclear enzyme involved in RNA/DNA hybrid degradation .

How does the RNASEH2A structure contribute to its enzymatic function?

The RNASEH2A structure features a canonical RNase H2 fold in its catalytic domain, but with a crucial C-terminal extension that is unique to eukaryotic RNase H2 enzymes . This C-terminal tail spans both auxiliary subunits (RNASEH2B and RNASEH2C) and is necessary for the formation of an enzymatically active complex . Specific residues in this C-terminal extension (such as R291H, K266A/R267A) are critical for enzyme activity while having minimal effect on complex stability . These residues may form an additional substrate-binding site or influence the quaternary structure of RNase H2 to modulate enzymatic activity.

What are the common synonyms and orthologous forms of RNASEH2A?

Researchers should be aware that RNASEH2A has several synonyms in the literature, including JUNB, RNASEHI, RNHIA, RNHL, THSD8, RNase H(35), RNase H2 subunit A, and AGS4 . RNASEH2A gene orthologs have been reported in multiple species including mouse, rat, bovine, frog, zebrafish, and chimpanzee . These orthologs show varying degrees of sequence conservation, with predicted reactivity ranging from 90% in yeast to 100% in several mammalian species .

What criteria should researchers use when selecting RNASEH2A antibodies?

When selecting RNASEH2A antibodies, researchers should consider:

• Target epitope location (N-terminal, middle region, or C-terminal)

• Host species to avoid cross-reactivity with experimental systems

• Clonality (monoclonal for consistency or polyclonal for increased sensitivity)

• Validated applications matching experimental needs

• Species cross-reactivity requirements

• Conjugation status for specialized applications

For example, if studying protein-protein interactions involving the C-terminus, researchers should avoid antibodies targeting this region as they may interfere with native interactions .

How can researchers validate RNASEH2A antibody specificity?

Methodological approach for antibody validation:

• Perform Western blot analysis using positive control samples (tissues/cells known to express RNASEH2A)

• Include negative controls using RNASEH2A knockout or knockdown systems

• Conduct peptide competition assays to confirm epitope specificity

• Test cross-reactivity with predicted species based on sequence homology

• Compare results with published literature using the same antibody

• Validate across multiple applications (WB, IHC, ICC) to ensure consistent detection

What technical considerations affect the performance of RNASEH2A antibodies in different applications?

For Western blotting:

• Sample preparation should preserve protein integrity while effectively denaturing the sample

• Blocking conditions may need optimization to reduce background

• Appropriate controls should include recombinant RNASEH2A protein

For immunohistochemistry:

• Fixation methods significantly impact epitope accessibility

• Antigen retrieval protocols may be necessary, especially for formalin-fixed samples

• Background can be reduced by optimizing antibody concentration and incubation conditions

For immunocytochemistry:

• Permeabilization protocols should be optimized to allow antibody access to nuclear RNASEH2A

• Co-staining with nuclear markers can confirm proper subcellular localization

How do mutations in RNASEH2A contribute to Aicardi-Goutieres Syndrome?

The RNASEH2A gene has been directly associated with Aicardi-Goutieres Syndrome (AGS), an autoinflammatory disorder . Mutations in all three subunits of human RNase H2 cause this early-onset progressive encephalopathy, which shares similarities with congenital viral infections and shows immunological features resembling systemic lupus erythematosus .

Molecular mechanisms include:

• Reduced enzymatic activity leading to accumulation of RNA:DNA hybrids

• Destabilization of the RNase H2 complex

• Triggering of innate immune responses by accumulated nucleic acid byproducts

• Activation of pattern recognition receptors that normally detect viral infections

Of 29 AGS-associated mutations identified, 25 can be mapped to the human RNase H2 structure, with 7 clustering at the interface of the RNASEH2A and RNASEH2C C-terminal regions .

What methodological approaches are recommended for studying RNASEH2A disease variants?

When investigating RNASEH2A disease variants, researchers should employ:

• Site-directed mutagenesis to recreate patient mutations in expression constructs

• Enzymatic activity assays to quantify the impact on catalytic function

• Protein stability assays to assess complex formation with RNASEH2B and RNASEH2C

• Cellular localization studies using fluorescently-tagged constructs

• Immunoprecipitation experiments to examine protein-protein interactions

• Patient-derived cell models or CRISPR-engineered cell lines to study physiological consequences

How can RNASEH2A antibodies facilitate research on nucleic acid-driven inflammation?

RNASEH2A antibodies enable several critical methodologies for studying nucleic acid-driven inflammation:

• Immunofluorescence microscopy to visualize RNA:DNA hybrid accumulation in disease models

• Chromatin immunoprecipitation to identify genomic regions where RNASEH2A functions

• Co-immunoprecipitation to identify novel interaction partners in inflammatory pathways

• Proximity ligation assays to study RNASEH2A association with innate immune sensors

• Immunoblotting to quantify protein expression in patient samples or disease models

What are the optimal conditions for using RNASEH2A antibodies in Western blotting?

For optimal Western blot results with RNASEH2A antibodies:

• Sample preparation:

  • Use RIPA or NP-40 buffer supplemented with protease inhibitors

  • Include phosphatase inhibitors if studying phosphorylation status

  • Heat samples at 95°C for 5 minutes in reducing Laemmli buffer

• Gel electrophoresis and transfer:

  • 10-12% polyacrylamide gels are suitable for resolving the 33.4 kDa RNASEH2A protein

  • PVDF membranes may provide better results than nitrocellulose for RNASEH2A detection

• Antibody incubation:

  • Optimal dilutions vary by antibody (typically 1:500-1:2000)

  • Overnight incubation at 4°C often yields better results than shorter incubations

  • BSA-based blocking solutions may reduce background compared to milk for some antibodies

How should researchers optimize immunohistochemistry protocols for RNASEH2A detection?

Methodological approach for IHC optimization:

• Tissue preparation:

  • Formalin fixation time should be minimized (24-48 hours optimal)

  • Paraffin embedding should follow standard protocols

• Antigen retrieval:

  • Heat-induced epitope retrieval using citrate buffer (pH 6.0) or EDTA buffer (pH 9.0)

  • Pressure cooking for 15-20 minutes often provides superior results to microwave methods

• Blocking and antibody incubation:

  • Block with 5-10% normal serum from the same species as the secondary antibody

  • Primary antibody incubation at 4°C overnight at optimized dilution

  • Secondary antibody incubation at room temperature for 1 hour

• Detection system:

  • DAB (3,3'-diaminobenzidine) or AEC (3-amino-9-ethylcarbazole) for chromogenic detection

  • Fluorescent secondary antibodies for co-localization studies

What controls should be included when using RNASEH2A antibodies?

Essential controls for RNASEH2A antibody experiments include:

• Positive controls:

  • Cell lines or tissues known to express RNASEH2A (most human cell lines express detectable levels)

  • Recombinant RNASEH2A protein for Western blotting

• Negative controls:

  • RNASEH2A knockout or knockdown samples

  • Secondary antibody-only controls to assess non-specific binding

  • Isotype controls (especially for monoclonal antibodies)

• Validation controls:

  • Peptide competition assays using the immunizing peptide

  • Multiple antibodies targeting different epitopes to confirm specificity

  • Comparison with mRNA expression data from the same samples

How can RNASEH2A antibodies be used to study RNA:DNA hybrid metabolism?

Methodological approaches for studying RNA:DNA hybrid metabolism:

• DNA:RNA Immunoprecipitation (DRIP) assays:

  • Use S9.6 antibody to pull down RNA:DNA hybrids

  • Follow with RNASEH2A immunoblotting to assess association

• Proximity Ligation Assays (PLA):

  • Detect in situ interactions between RNASEH2A and hybrid structures

  • Quantify changes in interaction frequency under different conditions

• Chromatin Immunoprecipitation followed by sequencing (ChIP-seq):

  • Map genomic locations of RNASEH2A binding

  • Correlate with R-loop mapping data to identify functional targets

• Immunofluorescence co-localization:

  • Visualize RNASEH2A localization relative to DNA damage markers

  • Quantify changes in response to replication stress or DNA damage

What methodological approaches are recommended for investigating RNASEH2A in genome stability?

To investigate RNASEH2A's role in genome stability:

• DNA damage response assays:

  • Immunofluorescence for γH2AX, 53BP1, or RAD51 foci in RNASEH2A-depleted cells

  • Comet assay to directly measure DNA breaks

• Replication stress analysis:

  • DNA fiber assays to measure replication fork progression and stalling

  • EdU incorporation assays to quantify S-phase progression

• Genetic interaction studies:

  • CRISPR-based synthetic lethality screens in RNASEH2A-mutant backgrounds

  • Double knockdown/knockout studies with DNA repair factors

• Genomic instability assessment:

  • Metaphase spread analysis for chromosomal aberrations

  • Micronuclei formation quantification

  • Next-generation sequencing to identify mutation patterns

How can researchers study RNASEH2A's interaction with its complex partners?

To study RNASEH2A interactions with complex partners:

• Co-immunoprecipitation approaches:

  • Use RNASEH2A antibodies to pull down the entire complex

  • Immunoblot for RNASEH2B and RNASEH2C to assess complex integrity

  • Include nuclease treatments to determine RNA/DNA-dependence of interactions

• Protein fragment complementation assays:

  • Create split reporter constructs (e.g., split luciferase) fused to RNASEH2A and partner proteins

  • Measure reconstituted reporter activity as indicator of protein-protein interaction

• Structural analysis methods:

  • Recombinant protein expression and purification of complex components

  • Size exclusion chromatography to assess complex formation

  • Hydrogen-deuterium exchange mass spectrometry to map interaction interfaces

• FRET (Förster Resonance Energy Transfer) microscopy:

  • Tag RNASEH2A and partners with compatible fluorophores

  • Measure energy transfer as indication of protein proximity in living cells

Table 1: Comparison of RNASEH2A Antibody Types and Applications