UBC5A Antibody
Description
Applications in Research
The UBC5A Antibody has been validated in multiple experimental contexts:
Western Blot
Immunohistochemistry (IHC)
Sandwich ELISA
Key Research Findings
UBE2D1 (UbcH5a) mediates K48- and K63-linked polyubiquitination, influencing diverse cellular pathways:
Biological Significance of UBE2D1
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Catalytic Mechanism: Contains a conserved E2 core domain with an active-site cysteine (C85) essential for ubiquitin thioester bond formation . Mutation (C85A) abolishes enzymatic activity .
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Disease Relevance:
Comparative Analysis of Ubiquitin Linkages
UBE2D1 participates in distinct ubiquitin chain types:
| Ubiquitin Linkage | Functional Role | Associated Pathways |
|---|---|---|
| K48 | Proteasomal degradation | p53 turnover, cell cycle regulation |
| K63 | Non-degradative signaling | NF-κB activation, DNA repair |
| M1 | Linear chains in NF-κB signaling | Immune and inflammatory responses |
Product Specs
Constituents: 50% Glycerol, 0.01M Phosphate Buffered Saline (PBS), pH 7.4
Target Background
Q&A
What is UbcH5a/UBE2D1 and what role does it play in cellular processes?
UbcH5a/UBE2D1 is a ubiquitously expressed ubiquitin-conjugating enzyme (E2) that plays a critical role in the ubiquitination pathway. This 17 kDa protein functions in concert with E3 ubiquitin ligases to mediate the ubiquitination of specific target proteins, marking them for degradation by the 26S proteasome or modifying their activity . UbcH5a/UBE2D1 contains a conserved E2 catalytic core domain with an active site cysteine residue that is essential for its enzymatic function .
The protein has been implicated in multiple cellular processes including protein quality control, cell cycle regulation, and immune responses. Pathologically, UbcH5a/UBE2D1 is involved in protein degradation mechanisms relevant to cancer progression and immune system function . Its ubiquitous expression reflects its fundamental importance in cellular homeostasis.
How conserved is UbcH5a/UBE2D1 across species?
UbcH5a/UBE2D1 demonstrates remarkable evolutionary conservation, particularly among mammals. Human UbcH5a/UBE2D1 shares 100% amino acid sequence identity with its mouse and rat orthologs, indicating the essential nature of this protein and its functional importance across mammalian systems . This perfect conservation makes rodent models particularly valuable for studying UbcH5a/UBE2D1 function with high translational relevance to human biology.
Within the UbcH5 family, human UbcH5a/UBE2D1 shares 89% amino acid sequence identity with UbcH5b and 88% with UbcH5c . This high degree of homology among family members suggests some functional redundancy, though each isoform likely has specific roles in certain cellular contexts or with specific E3 ligase partners.
What are the known protein targets of UbcH5a/UBE2D1-mediated ubiquitination?
UbcH5a/UBE2D1 participates in the ubiquitination of several critical regulatory proteins:
Understanding these targets helps explain the involvement of UbcH5a/UBE2D1 in cancer biology, immune responses, and cell death pathways. For example, its role in p53 ubiquitination through interaction with E6-AP connects UbcH5a/UBE2D1 to HPV-induced carcinogenesis .
What are the optimal conditions for using UbcH5a/UBE2D1 antibodies in Western blot applications?
For Western blot applications with UbcH5a/UBE2D1 antibodies, researchers should consider the following optimization parameters:
It's important to note that some UbcH5a/UBE2D1 antibodies may cross-react with other UBE2D family members due to high sequence homology. When specific detection of UbcH5a/UBE2D1 is required, validation using overexpression systems or knockout controls is strongly recommended .
How should samples be prepared for immunohistochemistry using UbcH5a/UBE2D1 antibodies?
Optimal immunohistochemistry (IHC) results for UbcH5a/UBE2D1 detection require careful attention to sample preparation:
UbcH5a/UBE2D1 antibodies have been successfully used for IHC on formalin-fixed paraffin-embedded human tissues, including prostate cancer and cervical cancer samples . The subcellular localization pattern is typically cytoplasmic with some nuclear staining, reflecting the protein's role in both compartments.
What are the recommended protocols for immunoprecipitation of UbcH5a/UBE2D1?
For successful immunoprecipitation (IP) of UbcH5a/UBE2D1 and its binding partners:
IP experiments have been successfully performed with UbcH5a/UBE2D1 antibodies in Jurkat cells . When studying transient E2-E3 interactions, consider crosslinking approaches to stabilize these interactions prior to cell lysis.
How can researchers distinguish between UbcH5a/UBE2D1 and closely related UbcH5 family members?
Distinguishing between highly homologous UbcH5 family members presents a significant challenge but can be accomplished through several complementary approaches:
| Strategy | Methodology | Advantages/Limitations |
|---|---|---|
| Isoform-specific antibodies | Use antibodies that target unique epitopes of UbcH5a/UBE2D1 | Limited availability of truly specific antibodies; requires extensive validation |
| siRNA/shRNA knockdown | Selective silencing of specific UbcH5 isoforms | Allows functional distinction; requires validation of knockdown specificity |
| Recombinant protein standards | Include purified recombinant proteins as controls | Allows assessment of antibody cross-reactivity |
| Mass spectrometry | Identification of isoform-specific peptides | High specificity but requires specialized equipment |
| Genetic models | CRISPR/Cas9 knockout of specific isoforms | Definitive approach but resource-intensive |
Given that human UbcH5a/UBE2D1 shares 89% and 88% amino acid sequence identity with UbcH5b and UbcH5c respectively , researchers should be aware that many commercially available antibodies may cross-react with multiple family members. For absolute specificity, combining immunological detection with genetic approaches is recommended.
What are the optimal experimental conditions for studying UbcH5a/UBE2D1-mediated ubiquitination in vitro?
In vitro ubiquitination assays using UbcH5a/UBE2D1 require careful attention to reaction conditions:
For studies focused specifically on E3 ligase activity without the confounding variables of the E1-E2 charging step, researchers can use pre-charged UbcH5a/UBE2D1-ubiquitin complexes . This approach eliminates the need for ATP, E1 enzyme, or extra ubiquitin, simplifying reaction conditions and interpretation of results.
What are common issues when detecting UbcH5a/UBE2D1 in Western blot applications and how can they be resolved?
Researchers may encounter several challenges when working with UbcH5a/UBE2D1 antibodies in Western blot applications:
| Issue | Potential Causes | Recommended Solutions |
|---|---|---|
| No signal | Insufficient protein, antibody concentration too low, protein degradation | Increase protein loading (30-50 μg), optimize antibody dilution, add fresh protease inhibitors |
| Multiple bands | Cross-reactivity with UbcH5 family members, post-translational modifications, degradation products | Use recombinant standards, perform knockout/knockdown validation, optimize sample preparation |
| High background | Non-specific antibody binding, insufficient blocking | Increase blocking time/concentration, optimize antibody dilution, try alternative blocking agents |
| Variable results between experiments | Inconsistent transfer, antibody degradation, variable expression levels | Standardize protocol, aliquot antibodies, include loading controls and positive controls |
For optimal detection of UbcH5a/UBE2D1 by Western blot, it's important to note the expected molecular weight is 17 kDa for the native protein and approximately 25 kDa (17 kDa UBE2D1 + 8.6 kDa ubiquitin) for the ubiquitin-charged complex .
How can researchers validate the specificity of UbcH5a/UBE2D1 antibodies?
Validating antibody specificity is crucial for reliable research results, particularly with highly homologous protein families like UbcH5/UBE2D:
What are the critical factors to consider when designing experiments to study UbcH5a/UBE2D1 interactions with E3 ligases?
Studying E2-E3 interactions presents unique challenges due to their often transient nature:
When using pre-charged UbcH5a/UBE2D1-ubiquitin complexes for studying E3 ligase function, it's important to note that reducing agents like DTT or β-mercaptoethanol can cause unintended thiolytic release of ubiquitin from the complex . This technical consideration is critical for experimental design and interpretation of results.
What emerging technologies are advancing UbcH5a/UBE2D1 research?
Several cutting-edge technologies are transforming our ability to study UbcH5a/UBE2D1 function and interactions:
| Technology | Application to UbcH5a/UBE2D1 Research | Potential Impact |
|---|---|---|
| Cryo-EM | Structural characterization of E2-E3 complexes | Reveals mechanistic details of ubiquitin transfer |
| Proximity labeling | Identification of transient UbcH5a/UBE2D1 interactors | Discovers novel E3 partners and substrates |
| Single-molecule techniques | Real-time monitoring of ubiquitination reactions | Elucidates reaction kinetics and processivity |
| Ubiquitin linkage-specific antibodies | Analysis of UbcH5a/UBE2D1-mediated ubiquitin chain types | Connects E2 activity to specific cellular outcomes |
| PROTAC technology | Targeted degradation through UbcH5a/UBE2D1 recruitment | Therapeutic applications |
These technologies will help address long-standing questions about the specificity determinants that govern which E3 ligases preferentially work with UbcH5a/UBE2D1 versus other E2 enzymes, and how these interactions are regulated in different cellular contexts.
What are the current gaps in understanding UbcH5a/UBE2D1 biology?
Despite decades of research, several important questions about UbcH5a/UBE2D1 remain unanswered:
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Isoform-specific functions: While UbcH5a/UBE2D1 shares high homology with UbcH5b/UBE2D2 and UbcH5c/UBE2D3, the specific biological contexts in which each isoform is preferentially utilized remain poorly defined.
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Regulatory mechanisms: How post-translational modifications and protein-protein interactions regulate UbcH5a/UBE2D1 activity in different cellular compartments and conditions requires further investigation.
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Disease relevance: Although UbcH5a/UBE2D1 has been implicated in cancer and immune responses , the specific contribution of this E2 enzyme versus other family members to disease progression needs clarification.
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Therapeutic targeting: Whether UbcH5a/UBE2D1 represents a viable therapeutic target, and how selective inhibition might be achieved given the high homology within the UbcH5 family, remains an open question.
Addressing these knowledge gaps will require combining genetic approaches with biochemical and structural studies, as well as developing more specific tools to distinguish between highly similar UbcH5 family members.
