PHF19 Antibody

Introduction to PHF19 Antibody

PHF19 antibodies are immunoglobulins specifically designed to target the PHF19 protein, which functions as a transcriptional repressor and plays crucial roles in epigenetic regulation. These antibodies are available in several formats:

• Polyclonal antibodies: Produced by immunizing animals (typically rabbits) with synthetic peptides corresponding to regions of human PHF19 protein

• Monoclonal antibodies: Offering high specificity for targeted PHF19 epitopes

• Recombinant monoclonal antibodies: Manufactured using recombinant DNA technology to ensure batch-to-batch consistency and future security of supply

These antibodies serve as invaluable research tools for investigating PHF19's roles in normal development and disease processes, particularly in cancer research and epigenetic studies.

Structure and Function of PHF19 Protein

Understanding the structure and function of the target protein is essential for effective antibody application.

PHF19 Isoforms

The PHF19 gene encodes two distinct protein isoforms in humans:

• PHF19L (long form): 580 amino acids containing multiple functional domains

• PHF19S (short form): 207 amino acids containing only the N-terminal Tudor and PHD1 domains

Domain Architecture

The PHF19 protein contains several functional domains that determine its biological activity:

• Tudor domain: Involved in protein-protein interactions

• Two PHD-type zinc fingers: Important for binding to modified histones

• Extended homology (EH) domain

• Chromo-like domain (in the long isoform only)

This domain architecture enables PHF19 to function as a Polycomb group (PcG) protein that specifically binds histone H3 trimethylated at 'Lys-36' (H3K36me3) and recruits the PRC2 complex, enhancing PRC2 H3K27me3 methylation activity .

Molecular Function of PHF19

PHF19 plays critical roles in epigenetic regulation through multiple mechanisms:

Interaction with PRC2 Complex

Research using PHF19 antibodies has demonstrated that the long isoform (PHF19L) specifically interacts with core components of the PRC2 complex, including EZH2, SUZ12, and EED, as confirmed by co-immunoprecipitation and mass spectrometry analyses . In contrast, the short isoform (PHF19S) does not interact with any PRC2 component, suggesting different functional roles for the two isoforms .

Chromatin Regulation

PHF19 facilitates the transition from active to repressed chromatin states in embryonic stem cells through a multi-step process:

1. Binding to H3K36me3, a mark for transcriptional activation

2. Recruiting H3K36me3 histone demethylases RIOX1 or KDM2B

3. Leading to demethylation of H3K36

4. Recruiting the PRC2 complex that mediates H3K27me3 methylation

5. Resulting in de novo silencing

This mechanism demonstrates how PHF19 contributes to the dynamic regulation of gene expression during development and in disease states.

Immunogen Information

Different PHF19 antibodies are raised against specific regions of the protein:

• Some target N-terminal regions of human PHF19 protein

• Proteintech's antibodies (11895-1-AP) target a fusion protein corresponding to amino acids 1-207 encoded by BC022374

• Other antibodies may target different epitopes, contributing to their specific applications and reactivity profiles

Applications of PHF19 Antibody

PHF19 antibodies serve multiple experimental purposes across various research applications.

Western Blotting

PHF19 antibodies are widely used for Western blotting to detect and quantify PHF19 protein expression:

• Typical dilutions range from 1:200 to 1:1000, depending on the specific antibody and sample

• Observed molecular weights include 22 kDa and 66 kDa bands, with the theoretical calculated molecular weight being 63 kDa

• The antibodies show reactivity with human, mouse, and rat samples, making them versatile for cross-species research

Immunoprecipitation

PHF19 antibodies effectively isolate PHF19 protein and its associated complexes:

• Typical dilutions of 1:100 are recommended for immunoprecipitation applications

• This application has been instrumental in identifying protein-protein interactions involving PHF19, particularly its association with PRC2 complex components

Immunofluorescence/Immunocytochemistry

For cellular localization studies:

• Dilutions typically range from 1:20 to 1:200

• Positive signals have been detected in mouse embryonic stem cells, confirming specificity and utility for developmental biology research

Chromatin Immunoprecipitation (ChIP)

PHF19 antibodies have proven valuable in ChIP experiments:

• They enable identification of genomic regions where PHF19 binds, providing insights into its role in gene regulation

• ChIP-seq analysis using PHF19 antibodies has revealed that PHF19 primarily binds near transcription start sites of target genes

Research Findings Using PHF19 Antibody

PHF19 antibodies have facilitated significant discoveries across multiple research areas.

Prostate Cancer

Research using PHF19 antibodies has revealed important functions in prostate cancer:

• PHF19L and PHF19S are expressed at higher levels in prostate cancer cell lines (PC3 and DU145) compared to normal prostate epithelial cells (RWPE1)

• PHF19L regulates proliferation and invasiveness in prostate cancer cells

• PHF19L knockdown results in significant changes in chromatin modification patterns and gene expression profiles

Chromatin Binding Profile

ChIP-seq experiments utilizing PHF19 antibodies have generated detailed binding profiles:

• In DU145 prostate cancer cells, 1245 significant PHF19-binding regions were identified, corresponding to 1010 target genes

• PHF19L primarily binds near transcription start sites of target genes

• Gene ontology analysis revealed significant enrichment of PHF19L at genes involved in essential biological processes including cell development, differentiation, proliferation, signaling pathways, and extracellular matrix organization

Epigenetic Regulation

Studies using PHF19 antibodies have elucidated its role in epigenetic modification:

• In the absence of PHF19L, there is a substantial increase in EZH2, SUZ12, and H3K27me3 levels, indicating PHF19L's role in regulating PRC2 activity

• PHF19 recruits the PRC2 complex to CpG islands and contributes to embryonic stem cell self-renewal

• PHF19 binding to H3K36me3 leads to recruitment of histone demethylases, followed by PRC2 recruitment and de novo silencing

Application-Specific Recommendations

Validation Methods

The specificity of PHF19 antibodies has been validated through multiple approaches:

• Knockdown experiments using shRNA against PHF19L significantly reduce antibody signal, confirming specificity

• Western blot analysis showing expected molecular weight bands at approximately 22 kDa and 66 kDa

• Immunoprecipitation followed by mass spectrometry identifying known interacting proteins

Future Perspectives in PHF19 Research

The continued development and application of PHF19 antibodies will likely contribute to:

• Deeper understanding of PHF19's role in cancer progression and potential therapeutic targeting

• Insights into epigenetic regulation mechanisms during development and disease

• Discovery of novel protein interactions and regulatory pathways

• Potential development of diagnostic or prognostic markers based on PHF19 expression patterns

PHF19 antibodies remain indispensable tools for advancing our knowledge of chromatin regulation and its implications in health and disease.