CENPQ Human

Centromere Protein-Q Human Recombinant
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Description

Functional Role in Centromere Biology

CENPQ operates within the CENPA-CAD complex, facilitating centromere assembly and chromosomal segregation . Key functions include:

  • Kinetochore recruitment: Directly interacts with CENP-H and CENP-I to stabilize kinetochore-microtubule attachments .

  • CENPA incorporation: Assists in depositing newly synthesized CENPA into centromeric chromatin via the CENPA-NAC complex .

  • Mitotic fidelity: Ensures proper chromosome congression and prevents aneuploidy .

CENPQ in Cancer: Diagnostic and Prognostic Implications

CENPQ overexpression is linked to aggressive tumor phenotypes and poor clinical outcomes.

Hepatocellular Carcinoma (HCC)

A 2024 study analyzing TCGA data revealed:

ParameterAssociation with High CENPQStatistical Significance
Tumor stage (T2-T4)Positivep = 0.016
Histologic gradePositivep < 0.001
Prothrombin timePositivep = 0.04

Esophageal Squamous Cell Carcinoma (ESCC)

CENPQ is upregulated in ESCC cell lines and correlates with cell cycle dysregulation (e.g., G2/M checkpoint, mitotic spindle pathways) .

Mechanistic Insights and Therapeutic Potential

CENPQ overexpression drives chromosomal instability (CIN) by disrupting centromeric chromatin architecture, leading to micronuclei formation and aneuploidy . Notably:

  • Immune modulation: High CENPQ expression in HCC correlates with immune checkpoint markers (PD-L1, CTLA4) and altered immune cell infiltration (e.g., reduced CD8+ T cells) .

  • Cell cycle regulation: CENPQ-associated differentially expressed genes (DEGs) in HCC enrich pathways like Hippo signaling and extracellular matrix degradation .

Research Gaps and Future Directions

  • Validation in clinical cohorts: Current findings rely on TCGA data; large-scale clinical validation is needed .

  • In vivo models: Mechanisms of CENPQ-driven tumorigenesis require exploration in animal studies .

  • Therapeutic targeting: CENPQ’s role in immune evasion positions it as a potential immunotherapeutic target .

Product Specs

Introduction
CENPQ, a component of the CENPH-CENPI-associated centromeric complex, plays a crucial role in targeting CENPA to centromeres. This targeting is essential for proper kinetochore function and mitotic progression. CENPQ facilitates the incorporation of newly synthesized CENPA into centromeres through its interaction with the CENPA-NAC complex.
Description
Recombinant CENPQ, produced in E. coli, is a single, non-glycosylated polypeptide chain consisting of 291 amino acids (residues 1-268) with a molecular weight of 33 kDa. This protein includes a 23 amino acid His-tag fused at the N-terminus and is purified using proprietary chromatographic techniques.
Physical Appearance
Clear, colorless solution, sterile-filtered.
Formulation
The CENPQ protein solution is provided at a concentration of 1 mg/ml in a buffer containing 20 mM Tris-HCl (pH 8.0) and 10% glycerol.
Stability
For short-term storage (2-4 weeks), keep at 4°C. For extended storage, freeze at -20°C. Adding a carrier protein like 0.1% HSA or BSA is recommended for long-term storage. Minimize repeated freeze-thaw cycles.
Purity
Purity is determined to be greater than 85.0% using SDS-PAGE analysis.
Synonyms
Centromere protein Q, CENPQ, CENP-Q, C6orf139, Centromere Protein-Q.
Source
Escherichia Coli.
Amino Acid Sequence
MGSSHHHHHH SSGLVPRGSH MGSMSGKANA SKKNAQQLKR NPKRKKDNEE VVLSENKVRN TVKKNKNHLK DLSSEGQTKH TNLKHGKTAA SKRKTWQPLS KSTRDHLQTM MESVIMTILS NSIKEKEEIQ YHLNFLKKRL LQQCETLKVP PKKMEDLTNV SSLLNMERAR DKANEEGLAL LQEEIDKMVE TTELMTGNIQ SLKNKIQILA SEVEEEEERV KQMHQINSSG VLSLPELSQK TLKAPTLQKE ILALIPNQNA LLKDLDILHN SSQMKSMSTF IEEAYKKLDA S.

Q&A

What is the primary function of CENPQ in human cells?

CENPQ belongs to the centromere protein family, which plays a crucial role in controlling mitotic chromosome segregation during cell division. The CENP gene family members show tightly controlled expression patterns in cells and are essential components of the kinetochore . Functionally, CENPQ contributes to the regulation of the cell cycle, particularly in processes related to mitotic cell organization, nuclear division, and organelle fission as revealed by GO analysis of CENPQ-associated differentially expressed genes . Methodologically, studies investigating CENPQ function typically employ RNA interference (RNAi) techniques, CRISPR-Cas9 gene editing, or overexpression systems to observe the resulting cellular phenotypes, particularly in relation to mitotic progression and chromosome segregation.

How is CENPQ expression typically measured in human tissue samples?

CENPQ expression in human tissues can be measured through multiple complementary techniques:

  • RNA-sequencing (RNA-seq): This high-throughput method quantifies CENPQ mRNA levels across different tissues. In studies analyzing CENPQ in hepatocellular carcinoma (HCC), researchers utilized RNA-seq data from 374 HCC samples and 50 normal tissue samples from The Cancer Genome Atlas (TCGA) .

  • Reverse Transcription Quantitative PCR (RT-qPCR): This method provides validation of gene expression findings. Researchers have confirmed CENPQ overexpression in clinical HCC samples relative to matched normal liver tissue specimens using RT-qPCR .

  • Immunohistochemistry (IHC): For protein-level detection, IHC using specific anti-CENPQ antibodies allows visualization of CENPQ expression in tissue sections. The Human Protein Atlas has been utilized to analyze CENPQ protein expression patterns .

  • Western blotting: This technique enables quantification of CENPQ protein levels in tissue or cell lysates.

When conducting expression studies, researchers should normalize CENPQ expression to established housekeeping genes and include appropriate technical and biological replicates to ensure reliability of results.

What are the common experimental models used to study CENPQ function?

Several experimental models are employed to investigate CENPQ function:

  • Cell line models: Human cancer cell lines (such as HepG2, Huh7 for liver cancer studies) are commonly used for in vitro investigation of CENPQ. These allow for gene knockdown/knockout studies, overexpression experiments, and analysis of downstream effects.

  • Organoid models: Three-dimensional organoid cultures can better recapitulate tissue architecture. Pancreatic ductal adenocarcinoma (PDAC) organoid models, for example, have been used to study complex morphogenesis processes that may involve centromeric proteins .

  • Animal models: Genetically modified mouse models with altered CENPQ expression can provide insights into in vivo effects.

  • Patient-derived samples: Analysis of CENPQ expression in clinical specimens provides direct relevance to human pathology, as seen in HCC studies where researchers compared CENPQ expression between tumor and adjacent normal tissues .

The choice of model depends on the specific research question, with combinations of approaches typically yielding the most comprehensive understanding of CENPQ function.

How does CENPQ expression correlate with clinicopathological features in cancer?

CENPQ expression has shown significant correlations with multiple clinicopathological features in hepatocellular carcinoma:

Clinicopathological FeatureCorrelation with CENPQ ExpressionStatistical Significance
WeightPositive associationp = 1.8e-03
BMIPositive associationp = 0.047
AgePositive associationp = 0.01
Alpha-fetoprotein (AFP)Positive associationp = 3.8e-04
T stageHigher expression in advanced stagesStatistically significant
Pathologic stageHigher expression in advanced stagesStatistically significant
Histologic gradeHigher expression in higher gradesStatistically significant
Prothrombin timePositive associationp = 0.04

These findings suggest that CENPQ mRNA expression is higher in HCC patients with malignant pathological features . Methodologically, such correlations are typically established through statistical analyses of large patient cohorts, using Wilcoxon rank sum tests and logistic regression. Researchers investigating CENPQ in other cancer types should consider performing similar comprehensive clinicopathological correlation analyses to determine if these associations are cancer-type specific or represent a broader pattern across malignancies.

What signaling pathways and biological processes are associated with CENPQ in cancer progression?

CENPQ is involved in multiple biological processes and signaling pathways relevant to cancer progression. Gene Ontology (GO) and pathway analyses of CENPQ-associated differentially expressed genes have revealed:

  • Biological Processes (BP):

    • Regulation of mitotic cell cycle

    • Organelle fission

    • Nuclear division

  • Cellular Components (CC):

    • Centromeric region

    • Chromosomal region

    • DNA replication preinitiation complex

  • Molecular Functions (MF):

    • Signaling receptor activator activity

    • Receptor ligand activity

    • Channel activity

    • Serine hydrolase activity

  • KEGG Pathways:

    • Cell cycle

    • Complement and coagulation cascades

    • Bile secretion

  • GSEA-Identified Pathways:

    • Complement system

    • Complement cascade

    • Cell cycle

    • Hippo-merlin signaling dysregulation

    • Degradation of the extracellular matrix

The involvement of CENPQ in these pathways suggests potential mechanistic roles in cancer development through cell cycle regulation, immune modulation, and extracellular matrix interactions. Researchers investigating CENPQ should consider designing experiments that specifically probe these pathways, such as using specific pathway inhibitors in combination with CENPQ manipulation to establish causative relationships.

What is the prognostic value of CENPQ expression in different cancer types?

CENPQ has demonstrated significant prognostic value, particularly in hepatocellular carcinoma:

Methodologically, these prognostic associations were established using Kaplan-Meier survival analyses with log-rank tests and Cox proportional hazards regression for multivariate analysis. For researchers studying CENPQ in other cancer types, it would be valuable to perform similar comprehensive survival analyses to determine if the prognostic significance of CENPQ is consistent across different malignancies.

How does CENPQ interact with other centromere proteins in the kinetochore complex?

CENPQ functions within a complex network of centromere proteins that together form the kinetochore. While the search results don't provide specific details about CENPQ interactions, research on centromere proteins generally shows:

  • Hierarchical Assembly: Centromere proteins follow a hierarchical assembly pattern where certain proteins (e.g., CENPA) are required for the recruitment of others. Understanding CENPQ's position in this hierarchy requires proximity ligation assays, co-immunoprecipitation studies, and super-resolution microscopy.

  • Functional Redundancy and Specificity: Some centromere proteins show functional redundancy, while others have unique roles. Studies comparing phenotypes after knockdown of multiple centromere proteins (including CENPQ, CENPL, CENPR, and CENPU) would help elucidate their relative contributions and potential compensatory mechanisms .

  • Co-expression Patterns: The co-expression of CENPL, CENPQ, CENPR, and CENPU in hepatocellular carcinoma suggests potential functional relationships between these proteins . Researchers should consider analyzing protein-protein interaction networks specific to CENPQ using techniques like BioID or IP-MS (Immunoprecipitation coupled with Mass Spectrometry).

For researchers studying CENPQ interactions, developing fluorescently tagged CENPQ constructs for live-cell imaging would enable visualization of protein dynamics during mitosis and identification of interaction partners through FRET (Fluorescence Resonance Energy Transfer) or FLIM (Fluorescence Lifetime Imaging Microscopy).

What methodological approaches are optimal for studying CENPQ's role in chromosomal instability?

Investigating CENPQ's role in chromosomal instability requires a multi-faceted methodological approach:

  • CENPQ Manipulation Strategies:

    • CRISPR-Cas9 knockout or knockdown via siRNA/shRNA to study loss-of-function effects

    • Inducible expression systems for controlled overexpression

    • Introduction of point mutations in functional domains to identify critical residues

  • Chromosomal Instability Assessment:

    • Metaphase spread analysis to quantify aneuploidy and structural aberrations

    • Fluorescence in situ hybridization (FISH) to detect specific chromosomal abnormalities

    • Live-cell imaging with fluorescently labeled histones to track chromosome segregation errors

    • Micronuclei formation assays as indicators of lagging chromosomes

  • Cell Cycle Analysis:

    • Flow cytometry to measure cell cycle distribution and polyploidy

    • BrdU incorporation assays to assess S-phase progression

    • Mitotic index determination via phospho-histone H3 staining

  • Molecular Mechanism Investigation:

    • ChIP-seq to identify CENPQ binding sites on chromosomes

    • RNA-seq to determine transcriptional consequences of CENPQ dysregulation

    • Phospho-proteomics to identify post-translational modifications and signaling events

  • In vivo Relevance:

    • Analysis of CENPQ expression in patient samples with known chromosomal instability profiles

    • Correlation of CENPQ levels with common chromosomal instability markers

Researchers should combine these approaches to comprehensively characterize how CENPQ contributes to maintaining chromosomal stability, particularly in the context of cancer where chromosomal instability is a common feature.

What is the potential of CENPQ as a diagnostic biomarker for cancer?

CENPQ shows considerable promise as a diagnostic biomarker, particularly for hepatocellular carcinoma:

  • Diagnostic Performance: ROC analysis indicates that CENPQ has good diagnostic ability for HCC with an area under the ROC curve (AUC) of 0.881 (95% CI: 0.845–0.918) . This suggests strong potential for distinguishing between cancerous and normal liver tissue.

  • Expression Differences: CENPQ expression is significantly higher in HCC tissues compared to normal liver tissues at both mRNA and protein levels . This clear differential expression strengthens its potential as a biomarker.

  • Pan-Cancer Relevance: Analysis indicates that CENPQ expression is upregulated in most cancer types, suggesting broad applicability for cancer screening, though it shows decreased expression in acute myeloid leukemia, indicating tumor-specific patterns .

For researchers exploring CENPQ's diagnostic potential:

  • Validation in larger, diverse patient cohorts is essential

  • Combination with other biomarkers may improve diagnostic accuracy

  • Evaluation of CENPQ in early-stage disease would determine its utility for early detection

  • Investigation of CENPQ in easily accessible samples (blood, urine) would enhance clinical applicability

Methodologically, researchers should employ multiple detection techniques (RT-qPCR, immunohistochemistry, ELISA) and validate findings across independent cohorts to establish CENPQ's robustness as a diagnostic biomarker.

How might CENPQ be targeted therapeutically in cancer treatment?

While the search results don't specifically address therapeutic targeting of CENPQ, several strategies can be proposed based on its biological functions:

  • Direct Inhibition Strategies:

    • Small molecule inhibitors targeting CENPQ protein-protein interactions

    • Peptide-based inhibitors that disrupt CENPQ incorporation into the kinetochore

    • Degraders (PROTACs) specifically targeting CENPQ for proteasomal degradation

  • Transcriptional/Translational Regulation:

    • Antisense oligonucleotides or siRNA-based therapies to reduce CENPQ expression

    • CRISPR interference (CRISPRi) approaches to suppress CENPQ transcription

  • Synthetic Lethality Approaches:

    • Identifying genes that, when inhibited in combination with CENPQ overexpression, lead to cancer cell death

    • Targeting downstream pathways activated by CENPQ overexpression

  • Immunotherapeutic Strategies:

    • Given CENPQ's correlation with immune cell infiltration , combining CENPQ targeting with immune checkpoint inhibitors

    • Development of CENPQ-targeted cancer vaccines if tumor-specific epitopes are identified

  • Combination Therapies:

    • Combining CENPQ inhibition with cell cycle inhibitors, as CENPQ is involved in cell cycle regulation

    • Targeting multiple centromere proteins simultaneously to overcome potential compensatory mechanisms

Researchers interested in developing CENPQ-targeted therapies should first establish mechanistic proof-of-concept in cell line and animal models, focusing on cancer types with high CENPQ expression and demonstrating selective toxicity to cancer cells versus normal cells.

What immune-related implications does CENPQ expression have in the tumor microenvironment?

The search results indicate that CENPQ expression correlates with immune cell infiltration in hepatocellular carcinoma , suggesting important implications for the tumor immune microenvironment:

  • Potential Mechanisms:

    • CENPQ may influence the expression of cytokines or chemokines that attract immune cells

    • Chromosomal instability resulting from CENPQ dysregulation could increase neoantigen production

    • CENPQ-associated signaling may affect immune checkpoint expression

  • Research Approaches:

    • Single-cell RNA sequencing of tumors with varying CENPQ expression to characterize immune cell populations

    • Spatial transcriptomics to analyze the co-localization of CENPQ-expressing cells and immune infiltrates

    • Functional assays measuring T-cell activation in the presence of CENPQ-overexpressing cancer cells

    • Analysis of correlation between CENPQ expression and response to immunotherapy

  • Clinical Implications:

    • CENPQ expression might serve as a predictive biomarker for immunotherapy response

    • Combined targeting of CENPQ and immune checkpoints could enhance therapeutic efficacy

    • Patients with different levels of CENPQ expression might benefit from tailored immunotherapeutic approaches

Researchers investigating the immune-related aspects of CENPQ should consider comprehensive immune profiling of tumors, functional immune assays, and correlation analyses with established immune signatures to fully characterize the relationship between CENPQ and tumor immunity.

What are the optimal experimental controls when studying CENPQ function?

When designing experiments to study CENPQ function, researchers should implement several key controls:

  • For Gene Expression Studies:

    • Multiple reference genes for normalization in qPCR (e.g., GAPDH, ACTB, 18S rRNA)

    • Tissue-matched normal controls when analyzing cancer samples

    • Positive controls (tissues known to express CENPQ) and negative controls

  • For Gene Manipulation Experiments:

    • Non-targeting siRNA/shRNA controls for knockdown experiments

    • Empty vector controls for overexpression studies

    • CRISPR non-targeting guide RNA controls for gene editing

    • Rescue experiments (re-expressing CENPQ after knockdown) to confirm specificity

  • For Protein Detection:

    • Antibody validation using CENPQ-knockout cells

    • Peptide competition assays to confirm antibody specificity

    • Secondary antibody-only controls for immunostaining

  • For Functional Assays:

    • Positive controls using known mitotic regulators (e.g., Aurora kinases)

    • Time-course experiments to capture dynamic processes

    • Multiple cell lines to ensure findings aren't cell type-specific

  • For Clinical Correlations:

    • Age and gender-matched controls

    • Stratification by relevant clinical parameters

    • Multiple independent cohorts for validation

These methodological controls ensure the reliability and reproducibility of results in CENPQ research and help distinguish CENPQ-specific effects from experimental artifacts.

How should researchers address heterogeneity in CENPQ expression across cancer subtypes and individual patients?

Cancer heterogeneity presents significant challenges in CENPQ research that require specific methodological approaches:

  • Inter-tumor Heterogeneity:

    • Analyze CENPQ expression across molecular subtypes of cancer (e.g., different HCC subtypes)

    • Correlate CENPQ expression with established molecular classifications

    • Perform meta-analyses across multiple independent cohorts

    • Stratify analyses by etiology (e.g., viral vs. non-viral HCC)

  • Intra-tumor Heterogeneity:

    • Use single-cell RNA sequencing to characterize CENPQ expression at the cellular level

    • Employ spatial transcriptomics or multiplex immunofluorescence to map CENPQ expression spatially within tumors

    • Analyze multiple regions from the same tumor to capture regional variation

  • Temporal Heterogeneity:

    • Compare CENPQ expression in primary tumors versus metastases

    • Analyze longitudinal samples (pre-treatment, during treatment, post-progression)

    • Correlate changes in CENPQ expression with treatment response

  • Statistical Approaches:

    • Use larger sample sizes to account for heterogeneity

    • Employ mixed-effects models that can account for inter-patient variability

    • Consider Bayesian approaches that can incorporate prior knowledge about heterogeneity

  • Experimental Strategies:

    • Derive cell lines or patient-derived xenografts from different regions of heterogeneous tumors

    • Use organoid models that better preserve tumor heterogeneity

    • Employ genetic barcoding to trace clonal evolution in relation to CENPQ expression

Addressing heterogeneity is crucial for translating CENPQ research findings into clinically meaningful applications and developing personalized approaches to cancer treatment based on CENPQ status.

What emerging technologies could advance our understanding of CENPQ function in human disease?

Several cutting-edge technologies hold promise for deepening our understanding of CENPQ biology:

  • Spatial Multi-omics:

    • Spatial transcriptomics to map CENPQ expression within tissue architecture

    • Spatial proteomics to visualize CENPQ protein localization alongside other proteins

    • Integration of spatial genomics to correlate chromosomal abnormalities with CENPQ distribution

  • Advanced Imaging Techniques:

    • Super-resolution microscopy (STORM, PALM) to visualize CENPQ at the kinetochore with nanometer precision

    • Lattice light-sheet microscopy for long-term live imaging of CENPQ dynamics

    • Correlative light and electron microscopy (CLEM) to link CENPQ localization with ultrastructural features

  • Genome Engineering:

    • Base editing and prime editing for precise modification of CENPQ sequences

    • Optogenetic control of CENPQ function to manipulate activity with spatiotemporal precision

    • Inducible degron systems for rapid and reversible CENPQ depletion

  • Single-Cell Technologies:

    • Single-cell multi-omics to correlate CENPQ expression with genomic, epigenomic, and proteomic features

    • Single-cell functional genomics (Perturb-seq) to assess CENPQ function across heterogeneous cell populations

    • Live-cell single-molecule tracking to monitor individual CENPQ molecules

  • Artificial Intelligence Applications:

    • Deep learning for image analysis of CENPQ localization patterns

    • Network analysis to predict CENPQ interactions and functional relationships

    • AI-driven drug discovery targeting CENPQ or its interaction partners

Researchers should consider incorporating these technologies into their experimental designs to overcome current limitations in understanding CENPQ function and to develop more effective diagnostic and therapeutic strategies.

What are the critical knowledge gaps in our understanding of CENPQ regulation in normal and disease states?

Despite growing interest in CENPQ, several critical knowledge gaps remain:

  • Transcriptional and Post-transcriptional Regulation:

    • Identity of transcription factors controlling CENPQ expression

    • Role of microRNAs and long non-coding RNAs in regulating CENPQ

    • Epigenetic mechanisms (DNA methylation, histone modifications) affecting CENPQ expression

  • Post-translational Modifications and Protein Regulation:

    • Patterns of phosphorylation, ubiquitination, or other modifications affecting CENPQ function

    • Protein degradation pathways controlling CENPQ turnover

    • Structural changes in CENPQ under different cellular conditions

  • Cell Type-Specific Functions:

    • Differences in CENPQ function across cell types (differentiated vs. stem cells)

    • Tissue-specific interaction partners and regulatory mechanisms

    • Role in specialized cell division processes (e.g., meiosis)

  • Disease Mechanisms:

    • Causative versus consequential role of CENPQ dysregulation in cancer progression

    • Potential involvement in diseases beyond cancer (developmental, neurological)

    • Mechanisms linking CENPQ to immune responses in the tumor microenvironment

  • Evolutionary Aspects:

    • Functional conservation versus divergence across species

    • Evolutionary pressures shaping CENPQ structure and function

    • Comparative analysis with other centromere proteins

Addressing these knowledge gaps requires integrated approaches combining genomics, proteomics, structural biology, and functional studies in diverse experimental systems, from cell lines to animal models and human samples.

Product Science Overview

Structure and Function

CENPQ is a subunit of the CENPH-CENPI-associated centromeric complex. This complex is responsible for targeting CENPA to centromeres, which is necessary for proper kinetochore function and mitotic progression . The kinetochore is a protein structure on the chromosome where the spindle fibers attach during cell division to pull sister chromatids apart.

The human recombinant form of CENPQ is typically produced in E. coli and is often fused with a His-tag at the N-terminus to facilitate purification. The recombinant protein is used in various research applications to study its function and interactions within the centromere complex .

Biological Importance

CENPQ plays a significant role in chromosome congression and the recruitment of other centromere proteins such as CENPO, CENPP, and CENPU. It is also involved in the recruitment of CENPE and PLK1 to the kinetochores . These interactions are crucial for the accurate segregation of chromosomes during cell division, ensuring that each daughter cell receives the correct number of chromosomes.

Clinical Relevance

Mutations or malfunctions in CENPQ can lead to various diseases, including spermatogenic failure, which affects male fertility . Understanding the function and structure of CENPQ is essential for developing potential therapeutic strategies for conditions related to chromosome segregation errors.

Research Applications

Recombinant human CENPQ is widely used in research to study its role in the centromere complex. It is utilized in various assays, including SDS-PAGE, to analyze its purity and molecular weight . The recombinant protein is also used to investigate the interactions between CENPQ and other centromere proteins, providing insights into the mechanisms of chromosome segregation.

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