PRC1 Antibody

What is the functional significance of PRC1 in cell division research?

PRC1 (Protein regulator of cytokinesis 1) functions as a crucial regulator of cytokinesis by cross-linking antiparallel microtubules at an average distance of 35 nM. It plays an essential role in controlling the spatiotemporal formation of the midzone and ensuring successful cytokinesis. Experimental evidence demonstrates that PRC1 is required for KIF14 localization to the central spindle and midbody, recruits PLK1 to the spindle, and stimulates PLK1 phosphorylation of RACGAP1 to enable ECT2 recruitment to the central spindle .

Methodologically, researchers investigating cell division should consider PRC1 as a critical target, particularly when studying:

• Spindle midzone formation

• Chromosome segregation mechanisms

• Midbody formation and cytokinesis completion

• Cancer cell proliferation (as PRC1 has been shown to act as an oncogene in bladder cancer cells)

What are the primary applications where PRC1 antibodies demonstrate highest sensitivity?

PRC1 antibodies show optimal effectiveness across multiple experimental applications with varying sensitivity levels as demonstrated in the following comparative table:

For optimal results, researchers should conduct pilot experiments to determine the ideal antibody concentration for their specific experimental conditions and sample types .

How should I optimize PRC1 antibody selection for studying mitotic spindle dynamics?

For studying mitotic spindle dynamics with PRC1 antibodies, methodological optimization should follow this research-validated workflow:

• Antibody selection based on experimental goal:

  • For protein localization studies: Choose antibodies validated for IF/ICC applications (such as mouse monoclonal [16F2] or rabbit monoclonal [EP1513Y])

  • For protein interaction studies: Select antibodies verified for IP applications

  • For quantitative expression analysis: Use WB-validated antibodies

• Validation considerations:

  • Confirm specificity against recombinant full-length PRC1

  • Verify absence of cross-reactivity with other proteins

  • Select antibodies that recognize evolutionarily conserved epitopes if working with multiple species

• Application-specific optimization:

  • For IF/ICC: Fix cells with 4% paraformaldehyde and permeabilize with 0.1% Triton X-100; co-stain with F-actin (phalloidin) and DNA (DAPI) to visualize cytoskeletal structure and nuclei

  • For IP studies: Use stringent washing conditions to minimize non-specific binding

  • For mitotic spindle dynamics: Time-course experiments capturing different mitotic phases are essential

• Controls implementation:

  • Include PRC1-depleted cells (via siRNA) as negative controls

  • Use cells in different cell cycle phases to confirm cell cycle-dependent localization patterns

What are the critical methodological considerations when using PRC1 antibodies in stem cell research?

When employing PRC1 antibodies in stem cell research, several critical methodological considerations must be addressed:

• Context-dependent PRC1 expression patterns:

  • PRC1 expression varies significantly between different stem cell compartments

  • In human developing neocortex, RING1B and H2AK119ub1 show comparable expression across cortical layers with minor increases in ventricular zone (VZ) and cortical plate (CP)

  • In mouse developing neocortex, Ring1a/b and H2AK119ub1 are uniformly distributed across zones with slight enrichment in VZ and CP

• Tissue preparation protocols:

  • For optimal results in tissue sections, fix tissue in 4% PFA in 120 mM phosphate buffer (pH 7.4) for 24h at 4°C

  • Perform antigen retrieval for 1h with 10 mM citrate buffer (pH 6.0) at 70°C

  • Block with 10% horse serum and 0.1% Triton in PBS

• Stem cell isolation and PRC1 detection:

  • For LGR5+ hair follicle stem cells, isolate via FACS prior to antibody application

  • For PRC1 activity assessment in stem cells, measure H2AK119Ub1 levels as a proxy

• Interpretation challenges:

  • PRC1 functions differ between intestinal stem cells (ISCs) and hair follicle stem cells (HFSCs)

  • Loss of PRC1 function leads to context-dependent molecular phenotypes

  • Comparative analysis across different stem cell types is essential to distinguish common vs. tissue-specific PRC1 roles

How can PRC1 antibodies be applied to investigate cytokinesis failure mechanisms in cancer cells?

Investigating cytokinesis failure in cancer cells using PRC1 antibodies requires a sophisticated multi-dimensional approach:

• Establish PRC1 depletion model systems:

  • Use PRC1-specific siRNA or CRISPR-Cas9 to generate PRC1-depleted cancer cell lines

  • Verify depletion efficiency by immunoblotting with anti-PRC1 antibodies

  • Document phenotypic changes including cytokinesis failure and multinucleation rates

• High-resolution imaging of cytokinesis defects:

  • Implement immunofluorescence with PRC1 antibodies (1:100-1:200 dilution) and co-staining with:

    • α-tubulin (microtubules)

    • F-actin (phalloidin for contractile ring)

    • DNA (DAPI)

  • Acquire time-lapse images at 60X magnification to track dynamic localization patterns

• Molecular interaction analysis:

  • Perform co-immunoprecipitation using anti-PRC1 antibodies to identify interacting partners

  • Historical precedent: Immunoprecipitation with anti-PRC1 antibodies revealed specific interaction with KIF4, a chromokinesin essential for cytokinesis

  • Analyze phosphorylation status of PRC1 using phospho-specific antibodies like α-PRC1P (phospho-Thr-481)

• Cancer-specific PRC1 dysregulation analysis:

  • Compare PRC1 expression and localization between normal and cancer cells

  • Analyze correlation between PRC1 expression levels and cytokinesis failure rates

  • Investigate PRC1's oncogenic activities in promoting cancer cell proliferation and inhibiting apoptosis

This approach has revealed that PRC1 depletion leads to severe cytokinesis defects: cells can progress to anaphase but exhibit failed interdigitating microtubule bundling, incomplete furrow formation, and ultimately become binucleated .

What strategies can resolve contradictory results when studying PRC1 oligomerization states using different antibodies?

When facing contradictory results in PRC1 oligomerization studies using different antibodies, implement this systematic troubleshooting approach:

• Epitope mapping and antibody validation:

  • Determine exact epitope recognition sites for each antibody

  • Different antibodies may preferentially recognize different oligomeric states

  • Example: Some antibodies specifically recognize Cdk-phosphorylated PRC1 monomers while others detect both phosphorylated and unphosphorylated forms

• Biochemical characterization of oligomeric states:

  • Apply sucrose gradient sedimentation combined with immunoblotting

  • Research has shown that unphosphorylated PRC1 forms oligomers (likely tetramers) via its N-terminal oligomerization domain

  • Phosphorylated PRC1 appears predominantly in monomeric form (~71 kDa)

• Comparative analysis using multiple detection methods:

  • Use native PAGE, gel filtration chromatography, and chemical crosslinking

  • Validate findings with recombinant PRC1 protein

  • Historical data shows bacterially expressed (unphosphorylated) His-PRC1 elutes from gel-filtration columns at ~300 kDa, suggesting oligomeric structures

• Structural domain analysis:

  • Generate and test N-terminal deletion mutants (e.g., PRC1ΔN184)

  • Research has demonstrated that deletion of the N-terminal oligomerization domain abolishes PRC1 oligomerizing activity in vivo

  • Phospho-specific antibodies like α-PRC1P detect only monomeric forms in lower molecular mass fractions

By implementing this strategy, researchers have successfully resolved contradictions in PRC1 oligomerization studies, revealing that Cdk phosphorylation negatively regulates PRC1 oligomerization and affects its microtubule binding properties during cell cycle progression.

How can researchers troubleshoot non-specific binding and background issues when using PRC1 antibodies in immunofluorescence?

To troubleshoot non-specific binding and background issues in PRC1 immunofluorescence experiments, follow this methodological framework:

• Optimize fixation and permeabilization:

  • Test different fixation methods: 4% paraformaldehyde shows optimal results for PRC1 detection

  • Compare permeabilization agents: 0.1% Triton X-100 is effective for most cell types

  • Critical step: Over-fixation can mask epitopes while under-fixation may compromise cellular architecture

• Refine blocking and antibody incubation parameters:

  • Blocking solution: 10% serum (matched to secondary antibody species)

  • Antibody dilution optimization: Test serial dilutions between 1:50 to 1:1600

  • Incubation conditions: Overnight at 4°C shows superior results compared to shorter incubations at room temperature

• Implement rigorous controls:

  • Negative controls: Omit primary antibody but maintain all other steps

  • Specificity controls: Use PRC1-depleted cells (siRNA treated)

  • Comparative controls: Use multiple validated PRC1 antibodies targeting different epitopes

• Cell cycle-specific considerations:

  • PRC1 localization changes dramatically throughout the cell cycle

  • Nuclear in interphase

  • Associated with mitotic spindles during mitosis

  • Localizes to midbody during cytokinesis

  • Synchronize cells to appropriate cell cycle stages for consistent results

Example troubleshooting results from validated protocols:

• Validated IF protocol shows distinct PRC1 localization patterns at 60X magnification

• Negative controls (no primary antibody) show minimal background staining

• In properly optimized experiments, PRC1 co-localizes with microtubules during metaphase-anaphase transition

What analytical methods should be employed when quantifying PRC1 expression levels in different tissue samples?

When quantifying PRC1 expression levels across different tissue samples, employ these analytical methods for reliable, reproducible results:

• Selection of appropriate quantification technique:

  • Western blotting: For whole tissue/cell population analysis

  • Immunohistochemistry/Immunofluorescence: For spatial distribution analysis

  • Flow cytometry: For single-cell distribution analysis

  • qRT-PCR: For mRNA expression analysis (complementary to protein studies)

• Western blot quantification protocols:

  • Sample preparation: 20-30 μg total protein per lane

  • Detection systems: Enhanced chemiluminescence or fluorescence-based systems

  • Normalization: Use housekeeping proteins (β-actin, GAPDH) as loading controls

  • Image analysis: Employ densitometry with appropriate background subtraction

• Immunohistochemistry/Immunofluorescence quantification methods:

  • Image acquisition: Standardize exposure settings across all samples

  • Nuclei segmentation: Use tools like Fiji plug-in StarDist 2D for accurate cell counting

  • Measurement parameters: Mean grey values of segmented nuclei

  • Statistical analysis: Test normal distribution using Kolmogorov-Smirnov and Shapiro-Wilk tests

• Analytical workflow for comparative studies:

  • Divide tissue samples into defined regions/zones (e.g., for brain samples: VZ, ISVZ, OSVZ, CP)

  • Use cell-type specific markers (e.g., SOX2, CTIP2) to identify distinct cell populations

  • Measure PRC1 expression in each defined region

  • Apply appropriate statistical tests (Tukey's multiple comparison test for multi-group comparisons)

Example quantification data from human neocortex studies shows differential expression of PRC1 components across germinal zones and cortical plate, with RING1B and H2AK119ub1 showing comparable expression across all cortical layers with minor increases in ventricular zone and cortical plate .

How should researchers evaluate contradictory findings regarding PRC1 function in different stem cell compartments?

When evaluating contradictory findings on PRC1 function across different stem cell compartments, implement this systematic comparative analysis framework:

• Methodological harmonization and standardization:

  • Use identical antibody clones and concentrations across experiments

  • Standardize isolation procedures for different stem cell populations

  • Implement matched genetic models (e.g., LGR5-GFP-ires-CreERT2/Ring1a−/−/Ring1bfl/fl compound models)

  • Ensure comparable tamoxifen treatment protocols for consistent PRC1 inactivation

• Multi-level comparative analysis:

  • Transcriptome profiling: Compare RNA-seq data between PRC1-depleted stem cells from different compartments

  • Protein interaction networks: Identify compartment-specific PRC1 binding partners

  • Epigenetic landscape: Analyze H2AK119Ub1 distribution patterns

  • Developmental trajectory analysis: Examine lineage commitment alterations

• Context-dependent interpretation framework:

  • Molecular outcome comparison: Research shows approximately 25% (255 genes) of up-regulated genes are common between intestinal stem cells (ISCs) and hair follicle stem cells (HFSCs) upon PRC1 inactivation

  • Lineage-specific response analysis: Differentiate universal from tissue-specific PRC1 functions

  • Transcription factor repertoire assessment: The specific outcome of PRC1 loss depends on the available transcription factors in each cell type

• Integration of seemingly contradictory results:

  • Research has revealed that despite PRC1 having a general role in preserving stem cell identity across compartments, the molecular phenotypes triggered by its loss are highly context-dependent

  • In intestinal stem cells, PRC1 loss leads to derepression of non-lineage-specific transcription factors

  • In hair follicle stem cells, PRC1 loss causes ectopic activation of an epidermal-specific program

  • This apparent contradiction is resolved by understanding the context-dependent nature of PRC1 function

This framework has successfully reconciled contradictory findings in PRC1 stem cell research, revealing that while PRC1 has a conserved role in maintaining lineage identity, the specific molecular consequences of its loss are determined by the cellular context and transcription factor availability in each stem cell compartment.

How can PRC1 antibodies be utilized to investigate the relationship between cytokinesis defects and cancer progression?

PRC1 antibodies can be instrumental in establishing the mechanistic links between cytokinesis abnormalities and cancer progression through this multi-dimensional research approach:

• Tumor sample analysis protocol:

  • Comparative tissue microarray analysis using PRC1 antibodies (1:50-1:500 dilution)

  • Correlation of PRC1 expression levels with clinical parameters (tumor grade, stage, patient outcomes)

  • Multivariate analysis to establish PRC1 as an independent prognostic factor

  • Research evidence: PRC1 acts as an oncogene promoting bladder cancer cell proliferation, inhibiting apoptosis, and driving carcinogenic progression

• Cell-based mechanistic studies:

  • Generate stable cell lines with inducible PRC1 overexpression or depletion

  • Track cytokinesis completion rates using time-lapse microscopy

  • Quantify multinucleation as a marker of cytokinesis failure

  • Assess genomic instability markers (micronuclei, aneuploidy)

  • Documented finding: PRC1 depletion leads to failed cytokinesis without affecting nuclear division

• Molecular pathways investigation:

  • Analyze PRC1's interactions with oncogenic signaling pathways using co-immunoprecipitation

  • Study phosphorylation status using phospho-specific antibodies

  • Investigate cross-talk with cell cycle regulators (cyclins, CDKs)

  • Research shows: PRC1 serves as a substrate for cyclin-dependent kinases, including Cdc2 and Cdk2

• In vivo tumor models assessment:

  • Generate xenograft models with PRC1-modulated cancer cells

  • Monitor tumor growth, invasion, and metastasis

  • Perform immunohistochemical analysis of tumor sections

  • Correlate cytokinesis defects with metastatic potential

This approach can reveal how dysregulation of PRC1, a key regulator of cytokinesis, contributes to genomic instability—a hallmark of cancer that drives tumor progression and therapeutic resistance.

What are the methodological considerations for investigating PRC1 post-translational modifications in different cellular contexts?

When investigating PRC1 post-translational modifications across cellular contexts, implement these methodological considerations:

• Modification-specific detection strategies:

  • Phosphorylation analysis: Use phospho-specific antibodies (e.g., anti-PRC1 phospho-Thr-481)

  • Site-directed mutagenesis: Generate phospho-mimetic (Thr→Glu) or phospho-deficient (Thr→Ala) mutants

  • Validation approach: Treatment with phosphatases (Cdc14A or CIAP) to confirm specificity

  • Experimental evidence shows that α-PRC1P specifically recognizes Cdk-phosphorylated PRC1 but not phosphatase-treated PRC1

• Cell cycle-dependent modification analysis:

  • Synchronization protocols: Double thymidine block or nocodazole arrest

  • Time-course studies: Sample collection at defined cell cycle stages

  • Validated finding: Unphosphorylated PRC1 forms oligomers via its N-terminal domain, while Cdk phosphorylation negatively affects oligomer formation

• Tissue-specific modification patterns:

  • Compare modification patterns across:

    • Primary cells vs. cell lines

    • Normal vs. cancer tissues

    • Different stem cell populations

  • Technical approach: Parallel immunoprecipitation followed by mass spectrometry

• Functional consequences assessment:

  • Structure-function analysis using modified vs. unmodified PRC1

  • Microtubule binding assays with recombinant proteins

  • Rescue experiments with phospho-mimetic or phospho-deficient mutants

  • Research has demonstrated that expression of EYFP-PRC1ΔC in cells lacking endogenous PRC1 rescues mitotic and cytokinetic defects

This methodological framework has revealed that phosphorylation status critically regulates PRC1 function by modulating its oligomeric state, which directly affects its ability to bundle microtubules during different cell cycle phases.