PPP1R14A Antibody

What is PPP1R14A and why is it significant in cell signaling research?

PPP1R14A (Protein Phosphatase 1 Regulatory Inhibitor Subunit 14A), also known as CPI-17, functions as a phosphorylation-dependent inhibitor of smooth muscle myosin phosphatase. When phosphorylated, it inhibits protein phosphatase 1 (PP1), leading to increased myosin phosphorylation and enhanced smooth muscle contraction without requiring elevated intracellular calcium concentrations . This mechanism represents a critical calcium sensitization pathway in smooth muscle physiology. PPP1R14A is approximately 16.7 kilodaltons and has significant roles beyond muscle contraction, including in cancer cell signaling pathways . Current research indicates its involvement in prostate cancer progression and as a potential therapeutic target in colon cancer , making it an increasingly important research target across multiple disciplines.

How should researchers optimize Western blotting protocols for PPP1R14A detection?

When optimizing Western blotting for PPP1R14A detection, researchers should consider several key factors:

• Sample preparation: Since PPP1R14A is phosphorylation-dependent, phosphatase inhibitors should be included in lysis buffers. The active form is phosphorylated at Thr38 (human), so phospho-state specific detection may require specialized preservation during extraction.

• Migration patterns: The expected molecular weight is 16.7 kDa, but observed migration often shows a 17 kDa band. Some researchers have noted inconsistencies between expected and observed band sizes, which may be due to post-translational modifications .

• Antibody dilutions: Published protocols recommend dilutions ranging from 1:500-1:2500 for primary antibodies, with specific examples of successful detection at 1:2500 (Abcam ab32213) and 1:500-1:1000 (Elabscience) .

• Validation approach: When validating antibody specificity, using transfected versus non-transfected cell lysates can provide clear positive and negative controls. For example, PPP1R14A transfected 293T cell lysates compared to non-transfected controls effectively demonstrate specificity .

• Detection of isoforms: When studying specific isoforms (e.g., long versus short isoforms in prostate cancer), antibody selection should consider epitope location relative to isoform differences .

When troubleshooting, remember that multiple bands may indicate different phosphorylation states or isoforms rather than non-specific binding.

What are the critical considerations for immunohistochemical detection of PPP1R14A in tissue samples?

For successful immunohistochemical detection of PPP1R14A:

• Antigen retrieval: Due to the small size of PPP1R14A (16.7 kDa) and its interactions with PP1, thorough antigen retrieval is essential. Heat-induced epitope retrieval in phosphate-buffered solutions is commonly employed.

• Antibody selection: Both monoclonal and polyclonal antibodies can be used for IHC. BosterBio's Anti-CPI17 alpha/PPP1R14A antibody has been validated for IHC applications . For phosphorylation-specific detection, antibodies recognizing the phosphorylated Thr38 residue are available.

• Dilution optimization: Starting dilutions of 1:50-1:200 are recommended for IHC applications , but optimization for specific tissue types is necessary.

• Controls: Positive control tissues should include smooth muscle tissues where PPP1R14A is highly expressed. For cancer studies, colorectal carcinoma tissue has been validated as a positive control .

• Interpretation: PPP1R14A shows primarily cytoplasmic localization , so nuclear staining may indicate non-specific binding. Both intensity and distribution patterns should be considered when evaluating expression levels.

When studying disease contexts, particularly in cancer research, comparison with normal adjacent tissue provides important internal controls for expression differences.

How can researchers effectively study the differential expression of PPP1R14A isoforms in cancer progression?

Studying PPP1R14A isoforms in cancer requires specific methodological approaches:

• Isoform identification: The human PPP1R14A gene produces multiple transcript variants. Research indicates the long isoform (ENST00000301242) and short isoform (ENST00000587515) have distinct functions in prostate cancer, with the long isoform promoting cell proliferation .

• Isoform-specific detection: For transcript analysis, primers should be designed to distinguish between isoforms. For protein detection, antibodies targeting regions unique to specific isoforms are preferable.

• Expression correlation with cancer phenotypes: Studies have shown that PPP1R14A first exon usage (ψ) correlates with Gleason score, clinical T stage, and progression-free survival in prostate cancer . This correlation can be assessed through:

  • RNA-seq analysis of isoform expression

  • Protein detection of specific isoforms using Western blot

  • Correlation with clinical parameters and survival data

• Functional validation: Overexpression of specific isoforms (as performed with PPP1R14A long isoform in 22Rv1 and PC3 cells) can determine their effect on cell proliferation .

• Pathway analysis: Gene set enrichment analysis (GSEA) revealed distinct pathways associated with PPP1R14A expression versus first exon usage:

  • Gene expression: associated with myogenesis pathway

  • First exon ψ: associated with MYC targets, DNA repair, and G2M checkpoint pathways

This multi-layered approach provides comprehensive understanding of how PPP1R14A isoforms contribute to cancer biology.

What role does PPP1R14A play in the relationship between asthma and colon cancer, and how can antibodies help elucidate this connection?

Recent research has revealed an intriguing connection between PPP1R14A, eosinophil counts, asthma, and colon cancer risk:

• Mediator identification: Mendelian randomization with mediation analyses identified eosinophil count as a mediator through which asthma may reduce the risk of colon cancer (CC) .

• Biomarker potential: Bioinformatic analyses identified PPP1R14A as an eosinophil-associated hub shared gene between asthma and colon cancer, suggesting it may function as a potential therapeutic target and biomarker .

• Investigation methodology:

  • Screening of eosinophil-associated shared genes between asthma and colon cancer identified eight candidates

  • LASSO algorithm further identified five genes including PPP1R14A

  • Validation in asthma datasets (GSE76262 and GSE67472) and TCGA data confirmed PPP1R14A as a significant hub gene

• Antibody applications: To investigate this connection, researchers can:

  • Use PPP1R14A antibodies for expression analysis in colon cancer and asthma tissues

  • Correlate expression with eosinophil infiltration using dual immunohistochemistry or immunofluorescence

  • Perform prognostic analysis of PPP1R14A expression in relation to clinical outcomes

• Future directions: Combining antibody-based detection of PPP1R14A with eosinophil markers could potentially develop prognostic assays for colon cancer risk stratification in asthma patients.

This emerging research area highlights how antibodies against PPP1R14A can bridge basic molecular studies with clinical applications in understanding disease connections.

How can PPP1R14A antibodies be used to study evolutionary conservation across vertebrate species?

The PPP1R14A (Cpi-17) gene family represents an evolutionarily conserved, vertebrate-specific group of protein phosphatase 1 inhibitors. When studying this conservation:

• Cross-reactivity analysis: Many PPP1R14A antibodies show cross-reactivity with multiple species due to conserved epitopes. For example:

  • Aviva Systems Biology antibody (ARP63944_P050) shows reactivity with human, mouse, rabbit, rat, bovine, and pig samples

  • MyBioSource polyclonal antibody reacts with human, mouse, and rat samples

• Conservation mapping: The central PHIN domain shows considerable conservation (30% identical and 46% similar within the PHIN domain between CPI-17a and Phi-1b), while N and C-termini are more divergent .

• Phosphorylation site conservation: The critical threonine phosphorylation site (Thr38 in humans) is conserved in zebrafish orthologs Cpi-17a (T31) and Cpi-17b (T37) .

• Experimental approach: When designing cross-species studies, researchers should:

  • Select antibodies targeting highly conserved regions

  • Validate cross-reactivity in each species of interest

  • Consider species-specific differences in molecular weight and post-translational modifications

  • Use positive controls from validated species when testing new applications

• Genomic organization: The zebrafish ppp1r14aa and ppp1r14ab genes have similar simple 4-exon genomic organization, providing insight into evolutionary conservation of gene structure .

How are PPP1R14A antibodies used to track developmental expression patterns in model organisms?

PPP1R14A antibodies are valuable tools for studying developmental expression patterns:

• Temporal expression analysis: In zebrafish development, expression of PPP1R14A orthologs shows distinct patterns:

  • ppp1r14aa: Detected in maternal mRNA, increases at sphere stage, declines through gastrulation, reappears at 72 hours post-fertilization (hpf)

  • ppp1r14ab: Present both maternally and zygotically with consistent expression

  • ppp1r14ba: Detected maternally, increases at sphere stage, declines by gastrulation, increases again during late somitogenesis

  • ppp1r14bb: Low expression early, increases during somitogenesis and remains elevated

• Methodology for developmental studies:

  • Western blotting can track protein expression levels across developmental stages

  • Immunohistochemistry allows spatial localization within developing tissues

  • Co-localization with tissue-specific markers can identify cell types expressing PPP1R14A

• Technical considerations:

  • Sample collection timing is critical for capturing transient expression patterns

  • Protein extraction from embryonic samples may require specialized protocols

  • Antibody selection should consider species-specific isoforms and developmental variants

• Correlation with function: Expression patterns can be correlated with developmental processes such as muscle formation, where PPP1R14A's role in contractility regulation is relevant.

This developmental approach provides insights into the temporal and spatial regulation of PPP1R14A expression during organism development.

What are the most common technical challenges when working with PPP1R14A antibodies and how can they be addressed?

Researchers frequently encounter several challenges when working with PPP1R14A antibodies:

• Inconsistent band size: Expected molecular weight is 16.7 kDa, but observed bands often appear at 17 kDa . Some antibodies detect higher MW bands (e.g., 41.91 kDa in immunogen detection) . These discrepancies may be due to:

  • Post-translational modifications, particularly phosphorylation

  • Protein-protein interactions resistant to denaturation

  • Isoform variation

  Solution: Include appropriate controls such as recombinant proteins or transfected vs. non-transfected cells to validate band identity.

• Phosphorylation state detection: Since PPP1R14A function is phosphorylation-dependent, detecting specific phosphorylation states is crucial but challenging.

  Solution: Use phospho-specific antibodies when studying active forms, and include appropriate phosphatase inhibitors during sample preparation.

• Cross-reactivity with related family members: The PPP1R14 family includes multiple members (A, B, C, D) with similar domains.

  Solution: Validate specificity using knockout or knockdown samples where available, or use epitope-specific antibodies targeting unique regions.

• Tissue-specific expression levels: Expression varies significantly between tissues, making detection challenging in low-expressing samples.

  Solution: Optimize protein loading amounts based on expected expression levels and consider using more sensitive detection methods for low-expressing tissues.

• Storage and stability issues: Some conjugated antibodies show reduced activity after freeze-thaw cycles.

  Solution: Store conjugated antibodies in light-protected vials, consider aliquoting to avoid repeated freeze-thaw cycles, and for longer storage (>12 months), dilute with up to 50% glycerol before freezing at -20°C to -80°C .

How can researchers validate the specificity of PPP1R14A antibodies in their experimental systems?

Proper validation of PPP1R14A antibodies is essential for reliable research outcomes:

• Positive and negative controls:

  • Positive controls: Tissues known to express PPP1R14A (smooth muscle, colorectal carcinoma)

  • Negative controls: Use isotype controls matching the primary antibody host species

  • Genetic controls: When available, use samples from knockout models or siRNA-treated cells to confirm specificity

• Multiple antibody validation: Use antibodies from different sources targeting distinct epitopes to confirm expression patterns.

• Blocking peptide experiments: Many suppliers offer blocking peptides (e.g., AAP63944 for Aviva antibody ARP63944_P050-HRP) that can be used to confirm specificity:

  • Pre-incubate antibody with excess blocking peptide

  • Run parallel assays with blocked and unblocked antibody

  • Specific signals should be eliminated or significantly reduced in the blocked condition

• Recombinant protein standards: Use recombinant PPP1R14A proteins as positive controls, with detection limits reported around 0.1 ng/ml for some antibodies .

• Correlation with other detection methods:

  • Compare protein detection with mRNA expression data

  • For phospho-specific antibodies, validate with treatments that alter phosphorylation status

• Publication validation status: Some antibodies have been validated in peer-reviewed publications, such as Abcam (ab32213) used at 1:2500 dilution for mouse samples in western blot and Santa Cruz Biotechnology (sc-48406) also validated for mouse samples in western blot .

This comprehensive validation approach ensures that experimental findings related to PPP1R14A are reliable and reproducible.

Bibliography

• Biocompare. "Anti-PPP1R14A Antibody Products." Biocompare database of commercially available antibodies showing applications, reactivity, and conjugate information.

• RayBiotech. "Anti-PPP1R14A Antibody." Detailed specification sheet for human PPP1R14A monoclonal antibody, including Western blot validation against transfected and non-transfected lysates.

• ProspecBio. "PPP1R14A Antibody Monoclonal." Technical description highlighting PPP1R14A's function as a phosphorylation-dependent inhibitor of smooth muscle myosin phosphatase.

• Norris et al. "The Evolution of Duplicated Genes of the Cpi-17/Phi-1 (ppp1r14) Family." Study analyzing the genomic organization and developmental expression patterns of PPP1R14A orthologs.

• Elabscience. "PPP1R14A Polyclonal Antibody." Product information specifying applications, observed molecular weight, and cellular localization.

• Boster Bio. "Anti-CPI-17 (K32) PPP1R14A Antibody." Technical data including immunohistochemistry validation in human colorectal carcinoma tissue.

• Wang et al. "Role of eosinophil counts in mediating the association between asthma and colon cancer." Research identifying PPP1R14A as an eosinophil-associated hub shared gene between asthma and colon cancer.

• He et al. "Novel role of prostate cancer risk variant rs7247241 on PPP1R14A isoform expression and function." Study investigating PPP1R14A isoforms and their role in prostate cancer.

• Sigma-Aldrich. "Anti-PPP1R14A antibody produced in rabbit." Product specification for prestige antibody with validated applications.

• Grywalska et al. "The extrafollicular B cell response is a hallmark of childhood systemic lupus erythematosus." Research mentioning CD markers in immune cell populations.

• Labome. "Mouse Ppp1r14a antibody." Database of validated antibodies with publication citations.

• Aviva Systems Biology. "PPP1R14A Antibody - N-terminal region : HRP (ARP63944_P050-HRP)." Product information including predicted species reactivity and storage recommendations.

• LifeSpan BioSciences. "IHC-plus™ PPP1R14A / CPI-17 Polyclonal Antibody." Product specifications for IHC and ELISA applications.