ubh-4 Antibody
Description
Target Overview: UBH-4 Protein
The UBH-4 protein in C. elegans is a deubiquitinating enzyme (DUB) involved in proteasome regulation and ubiquitin signaling. Key features include:
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Structure: Contains a conserved ubiquitin C-terminal hydrolase domain .
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Function: Regulates proteasome activity, protein degradation, and autophagy .
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Orthology: Shares functional homology with human BAP1, which is implicated in DNA repair and chromatin remodeling .
Research Applications of UBH-4 Antibody
UBH-4 antibodies are primarily used for:
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Immunohistochemistry (IHC): Localizing UBH-4 expression in C. elegans tissues .
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Western Blotting: Detecting UBH-4 protein levels in lysates .
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Functional Studies: Investigating genetic interactions, proteasome dynamics, and autophagy modulation .
3.1. Proteasome Regulation and Genetic Interactions
UBH-4 inactivation via CRISPR-Cas9 or RNAi reveals:
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Synthetic Interaction with rpn-9:
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Proteasome Activity: ubh-4 deletion does not alter 20S proteasome levels but sensitizes organisms to proteotoxic stress .
3.2. Autophagy Modulation
UBH-4 knockdown affects autophagy in a tissue-specific manner in C. elegans:
Pharmacological and Therapeutic Insights
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Bortezomib Sensitivity: ubh-4 mutants show heightened sensitivity to the proteasome inhibitor Bortezomib, suggesting UBH-4 as a potential therapeutic target for proteostasis-related diseases .
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DUB Inhibitors: Compounds like b-AP15 (dual inhibitor of UBH-4 and USP-14) increase polyubiquitinated protein accumulation, whereas IU1 (USP-14 inhibitor) reduces it, highlighting context-dependent effects .
Technical Considerations
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Antibody Validation: Commercial UBH-4 antibodies (e.g., HPA019219) are validated for IHC and Western blotting, with specificity confirmed via protein arrays and tissue staining .
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Model Limitations: ubh-4 is non-essential in C. elegans, enabling viability studies but complicating phenotype observation .
Future Directions
Product Specs
Constituents: 50% Glycerol, 0.01M PBS, pH 7.4
Target Background
Q&A
Basic Research Questions
How do I validate UBH-4 antibody specificity in C. elegans models?
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Perform siRNA-mediated ubh-4 knockdown followed by Western blotting to confirm reduced UBH-4 protein levels. Use anti-UCHL5 (human homolog) or custom anti-UBH-4 antibodies with cross-reactivity validation in C. elegans lysates .
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Include controls: (i) Wild-type vs. ubh-4 CRISPR mutants (e.g., ubh-4(cer27)) , (ii) Secondary antibody-only lanes, and (iii) HSC70 as a loading control .
What experimental models are optimal for studying UBH-4’s role in proteostasis?
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Human cells: GFP-LC3-RFP-LC3ΔG HeLa cells for autophagic flux analysis via LC3-II/P62 Western blotting .
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C. elegans: Use strains expressing mCherry::GFP::LGG-1 to quantify autophagosomes (GFP+/mCherry+) and autolysosomes (GFP−/mCherry+) in tissues like the intestine or hypodermis .
How to distinguish UBH-4’s effects from USP-14 in autophagy regulation?
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Apply selective inhibitors: b-AP15 (dual UBH-4/USP-14 inhibitor) vs. IU1 (USP-14-specific). Compare polyubiquitin accumulation using reporter strains (e.g., C. elegans polyubiquitin::GFP) .
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Quantify tissue-specific responses via confocal microscopy (e.g., intestinal vs. pharyngeal autophagosome counts) .
Advanced Research Questions
How to resolve conflicting data on UBH-4’s role in polyubiquitinated protein accumulation?
Methodological recommendations:
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Combine RNAi with proteasome inhibitors (e.g., MG-132) to block compensatory degradation .
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Use tissue-specific promoters (e.g., ges-1 for intestine) to isolate UBH-4 effects .
How to design studies analyzing tissue-specific autophagy modulation by UBH-4?
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Step 1: Generate transgenic C. elegans with tissue-specific RNAi (e.g., rde-1 rescue strains) .
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Step 2: Quantify autophagic structures using mCherry::GFP::LGG-1 reporters in:
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Step 3: Validate via transmission electron microscopy for ultrastructural autophagosome analysis .
What strategies address UBH-4’s synthetic lethality with proteasome subunits?
Methodological Notes for Data Reproducibility
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Antibody dilution: Start with manufacturer recommendations (e.g., 1:500–1:10,000), but optimize for tissue lysate complexity .
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Autophagy flux quantification: Use BAFA (lysosomal inhibitor) to block degradation and measure LC3-II accumulation .
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Controls for pharmacological studies: Include DMSO vehicle controls and validate inhibitor efficacy via ubiquitin-binding assays .
