TCEA3 Antibody

What is TCEA3 and what are its key structural features?

TCEA3 is a crucial member of the TFS-II family that plays a vital role in transcription by facilitating RNA polymerase II release from transcriptional arrest. This 348 amino acid protein contains one TFIIS N-terminal domain, one TFIIS central domain, and one TFIIS-type zinc finger . TCEA3 functions primarily in the nucleus where it binds to RNA polymerase II, activating the polymerase's intrinsic RNA cleavage activity, enabling nascent transcript cleavage and formation of new 3′-termini, thus allowing transcription to resume after arrest .

What types of TCEA3 antibodies are available for research applications?

Multiple formats of TCEA3 antibodies are commercially available, including:

These antibodies target different epitopes of TCEA3, with some recognizing specific amino acid regions such as AA 79-169 or AA 1-299 .

What are the primary applications for TCEA3 antibodies?

TCEA3 antibodies have been validated for multiple experimental applications including:

• Western blotting for protein expression analysis

• Immunoprecipitation for protein interaction studies

• Immunofluorescence for subcellular localization

• ELISA for quantitative analysis

• Immunohistochemistry for tissue expression pattern analysis

The choice of application should be guided by the specific scientific question and experimental design.

How can I optimize TCEA3 immunofluorescence protocols to distinguish nuclear versus cytoplasmic localization?

Research has shown that TCEA3 exhibits differential localization patterns depending on cellular context. During differentiation, TCEA3 translocates from the cytoplasm to the nucleus . To accurately capture this dynamic localization:

• Fixation method selection: Use 4% paraformaldehyde for general applications or -20°C acetone for preserving nuclear integrity as demonstrated in published protocols

• Nuclear counterstain: Always include DAPI nuclear staining as a reference point

• Confocal analysis: Employ z-stack imaging to verify true nuclear versus cytoplasmic distribution

• Cellular context consideration: In cancer cell lines (e.g., RMS), TCEA3 appears primarily nuclear with some cytoplasmic localization, particularly in ERMS cell lines

• Positive controls: Include differentiating C2C12 cells, which show dynamic TCEA3 localization changes

The subcellular shuttling of TCEA3 appears functionally significant, as nuclear localization correlates with its transcriptional activities .

What controls are essential when validating TCEA3 antibody specificity?

To ensure experimental rigor when using TCEA3 antibodies:

• Expression validation: Compare endogenous versus overexpressed TCEA3 signals using a validated expression vector (e.g., pTCEA3)

• Knockdown controls: Include TCEA3-depleted samples using validated siRNAs or shRNAs targeting TCEA3

• Cross-reactivity assessment: Verify specificity among TCEA family members (TCEA1, TCEA2, TCEA3) if using antibodies that may recognize conserved domains

• Recombinant protein controls: Use purified TCEA3 protein (such as AA 1-299) as a positive control for antibody validation

• Null cell types: Include cell lines with undetectable TCEA3 expression (HeLa, PC3, MCF7, and MDA-321 have been documented as TCEA3-negative)

These controls help distinguish true TCEA3 signals from background or cross-reactive signals with other TCEA family members.

How can TCEA3 antibodies be used to study its interaction with RNA polymerase II and transcription elongation mechanisms?

To investigate TCEA3's role in transcription elongation:

• Co-immunoprecipitation optimization: Use nuclear extracts from differentiated cells (e.g., C2C12 myotubes) with anti-TCEA3 antibody to pull down RNAPII complexes

• Sequential ChIP (ChIP-reChIP): Perform RNAPII ChIP followed by TCEA3 ChIP to identify co-occupied genomic regions

• Traveling ratio analysis: Combine TCEA3 ChIP with RNAPII ChIP to calculate pause indices at TCEA3-bound genes

• Elongation assay setup: Use TCEA3 immunodepletion followed by in vitro transcription elongation assays to assess functional contributions

Research has demonstrated that TCEA3 co-localizes with RNAPII and can be found at promoters and throughout the coding regions of genes like Tnni2 . The recruitment of both RNAPII and TCEA3 is enhanced during differentiation, positively correlating with transcriptional activity .

How can TCEA3 antibodies be used to study muscle differentiation and myogenic factor interactions?

For investigating TCEA3's role in muscle development:

• Co-immunoprecipitation protocol:

  • Transfect cells with TCEA3 and myogenic factors (MYOD1 or MYOG)

  • Immunoprecipitate with antibodies against MYOG or MYOD1

  • Detect associated TCEA3 by western blot with anti-TCEA3 antibody

• ChIP-seq experimental design:

  • Perform ChIP with anti-TCEA3 antibody in differentiating C2C12 cells

  • Analyze co-occupancy with MYOD1 and MYOG binding sites

  • Compare TCEA3 binding patterns before and after differentiation

• Proximity ligation assay:

  • Use anti-TCEA3 antibody alongside antibodies against myogenic factors

  • Visualize direct protein interactions in situ in muscle tissue or differentiating myoblasts

Research has confirmed that TCEA3 interacts with both MYOG and MYOD1, and is co-recruited with these myogenic regulatory factors to their target promoters .

What methodologies can be employed to study TCEA3's role in cancer cell apoptosis?

To investigate TCEA3's apoptotic functions in cancer research:

• Apoptosis detection following TCEA3 expression:

  • Establish stable TCEA3-expressing cancer cell lines

  • Perform TUNEL assays to detect DNA fragmentation

  • Use flow cytometry with Annexin V and propidium iodide to quantify apoptotic and dead cells

• Caspase pathway analysis:

  • Detect cleaved caspase-3, -8, and -9 using western blotting

  • Apply specific caspase inhibitors (intrinsic pathway, extrinsic pathway, or pan-caspase)

  • Monitor caspase-3 cleavage by western blot to determine pathway dependency

• Combination therapy evaluation:

  • Treat TCEA3-expressing cells with chemotherapeutic drugs (e.g., TRAIL)

  • Assess synergistic effects on apoptosis induction

  • Analyze downstream signaling pathway activation

Research has demonstrated that ectopic expression of TCEA3 in cancer cell lines (RMS, HeLa, MCF7, MDA-231, and PC3) inhibits proliferation and initiates apoptosis through both intrinsic and extrinsic pathways .

How can researchers use TCEA3 antibodies to study its deubiquitination and protein stability regulation?

For investigating post-translational regulation of TCEA3:

• Ubiquitination assay protocol:

  • Transfect cells with HA-Ub and Myc-TCEA3

  • Treat with proteasome inhibitor MG132

  • Immunoprecipitate with anti-Myc antibody

  • Detect poly-ubiquitination with anti-HA or anti-Ub antibodies

• Deubiquitination analysis:

  • Co-express TCEA3 with deubiquitinating enzymes (e.g., USP47)

  • Immunoprecipitate TCEA3 and analyze ubiquitination status

  • Compare ubiquitination levels with and without deubiquitinase expression

• Protein stability assessment:

  • Treat cells with cycloheximide to block protein synthesis

  • Monitor TCEA3 degradation kinetics by western blot

  • Compare stability in the presence or absence of deubiquitinating enzymes

Research has identified USP47 as a deubiquitinase that regulates TCEA3 stability. USP47 interacts with TCEA3, reduces its ubiquitination, and increases its expression levels in a dose-dependent manner .

How do I address inconsistent TCEA3 detection in western blotting?

If experiencing variability in TCEA3 western blot results:

• Protein extraction optimization:

  • Use nuclear extraction protocols for enhanced TCEA3 recovery

  • Include proteasome inhibitors (e.g., MG132) to prevent degradation during sample preparation

  • Consider phosphatase inhibitors as post-translational modifications may affect antibody recognition

• Antibody selection considerations:

  • C-7 mouse monoclonal antibody has been validated for western blotting of human, mouse, and rat TCEA3

  • Polyclonal antibodies targeting AA 79-169 or other epitopes provide alternatives if monoclonal antibody yields inconsistent results

• Loading control selection:

  • Use nuclear protein loading controls when analyzing nuclear fractions

  • GAPDH has been documented as a suitable loading control for TCEA3 western blots

Research has demonstrated that TCEA3 undergoes proteasomal degradation in various cell types, which may contribute to detection challenges .

How can I enhance TCEA3 signal in immunohistochemistry applications?

For improved IHC detection of TCEA3:

• Antigen retrieval optimization:

  • Heat-mediated antigen retrieval with EDTA buffer pH 9 has been documented to enhance TCEA3 detection

  • Compare with citrate buffer (pH 6) to determine optimal conditions for your tissue type

• Signal amplification strategies:

  • Consider using HRP-conjugated TCEA3 antibody for direct detection

  • Employ tyramide signal amplification for low abundance detection

  • Use of biotin-free detection systems to reduce background

• Background reduction approaches:

  • Include appropriate blocking steps with 5% normal serum

  • Use IgG subtype-specific secondary antibodies

  • Employ tissue-specific blocking reagents for high-background tissues

When analyzing TCEA3 in cancer tissues, remember that TCEA3 expression is often downregulated compared to normal tissues, which may necessitate more sensitive detection methods .

How can TCEA3 antibodies be leveraged in stem cell research?

For exploring TCEA3's role in pluripotency and differentiation:

• Embryonic stem cell applications:

  • Monitor TCEA3 expression during differentiation using immunofluorescence

  • Perform ChIP-seq to map TCEA3 occupancy in pluripotent versus differentiating cells

  • Compare TCEA3 binding patterns with pluripotency and differentiation markers

• Lineage commitment analysis:

  • Establish TCEA3 overexpression or knockdown ES cell lines

  • Analyze differentiation potential using lineage-specific markers

  • Examine TGF-β/Nodal pathway component expression and activation

Research has demonstrated that Tcea3 is highly expressed in embryonic stem cells and rapidly disappears during differentiation . While altered TCEA3 expression does not directly influence self-renewal, it critically regulates differentiation potential upon exposure to differentiation signals, functioning as a molecular rheostat to control Smad2/3 signaling .

What methodological approaches can be used to distinguish between TCEA1, TCEA2, and TCEA3 functions in experimental systems?

To differentiate between TCEA family members:

• Isoform-specific antibody validation:

  • Perform western blot analysis using recombinant TCEA1, TCEA2, and TCEA3 proteins

  • Utilize cells with known differential expression of TCEA family members

  • Consider pan-TCEA antibodies for total TCEA detection followed by isoform-specific analysis

• Expression pattern analysis:

  • Compare tissue distribution using immunohistochemistry with isoform-specific antibodies

  • Analyze subcellular localization patterns, as TCEA3 shows dynamic nuclear-cytoplasmic shuttling

  • Examine temporal expression during differentiation or development

• Functional complementation experiments:

  • Deplete individual TCEA isoforms

  • Rescue with expression constructs for each isoform

  • Analyze isoform-specific functional outcomes

Unlike TCEA1 and TCEA2, TCEA3 shows tissue-restricted expression, with highest levels in skeletal muscle and varying levels in other tissues including breast, ovarian, prostate, and embryonic stem cells .