PRPF18 Antibody

Introduction to PRPF18 Antibody

PRPF18 antibodies are immunoglobulins engineered to recognize and bind to the PRPF18 protein with high specificity and affinity. These research tools enable scientists to detect, quantify, localize, and isolate this critical splicing factor from biological samples. PRPF18 antibodies are available in multiple formats, including polyclonal and monoclonal variants, each offering specific advantages depending on the experimental context. These antibodies represent essential components in the molecular biologist's toolkit, particularly for those investigating RNA metabolism, gene expression regulation, and the intricate mechanisms of pre-mRNA processing.

Researchers typically generate these antibodies by immunizing host animals (commonly rabbits or mice) with PRPF18-specific peptides or recombinant protein fragments, resulting in immune responses that produce antibodies with high specificity toward the target protein. The resulting antibodies can recognize either native or denatured forms of PRPF18, depending on the immunization strategy and antibody production methodology employed .

PRPF18 Protein Background

Understanding the fundamental characteristics of the PRPF18 protein provides essential context for appreciating the utility and applications of antibodies directed against it.

Structure and Function

PRPF18, also known as HPRP18, is a 342 amino acid protein that plays a critical role in the second step of pre-mRNA splicing . As a member of the PRP18 family, this protein contains seven WD repeats, which are structural motifs typically involved in protein-protein interactions within multi-component molecular complexes . These structural features enable PRPF18 to function effectively within the spliceosome, the complex molecular machinery responsible for removing introns from pre-mRNA molecules during RNA processing.

The protein localizes predominantly to nuclear speckles, which are subnuclear structures enriched in pre-mRNA splicing factors and other RNA processing components . This localization pattern directly correlates with its functional role in RNA splicing activities. PRPF18 exists as two alternatively spliced isoforms, adding another layer of complexity to its functional profile and potentially influencing its interactions with other splicing components .

Genetic Information and Conservation

The PRPF18 gene resides on human chromosome 10p13, a region that contains numerous genes implicated in various biological processes and disease states . Chromosome 10 harbors over 800 genes spanning approximately 135 million nucleotides, including the PTEN tumor suppressor gene, which, when defective, contributes to Cowden syndrome, a genetic predisposition to cancer development .

The PRPF18 protein demonstrates remarkable evolutionary conservation across mammalian species, with certain regions showing 100% sequence identity between human and mouse orthologs and 99% identity with rat orthologs . This high degree of conservation suggests that PRPF18 performs essential cellular functions that have been preserved throughout mammalian evolution, underscoring its biological significance.

Types of PRPF18 Antibodies

PRPF18 antibodies are available in several formats, each with distinct characteristics suited to particular experimental applications.

Polyclonal PRPF18 Antibodies

Polyclonal antibodies against PRPF18 derive from the serum of animals (typically rabbits) immunized with PRPF18-specific peptides or protein fragments. These antibodies recognize multiple epitopes on the PRPF18 protein, potentially offering enhanced sensitivity for detecting low-abundance targets, albeit sometimes with reduced specificity compared to monoclonal alternatives.

A notable example is the PRPF18 Polyclonal Antibody from Invitrogen (Thermo Fisher), which researchers generate using a specific immunogen sequence corresponding to selected regions of the human PRPF18 protein . This antibody demonstrates high ortholog reactivity, exhibiting 100% sequence identity with mouse PRPF18 and 99% with rat PRPF18, making it particularly versatile for cross-species research applications .

Another example is the rabbit polyclonal antibody to PRPF18 available from antibodies.com (catalog number A28103), which is generated using a synthetic peptide corresponding to amino acids 223-268 of human PRPF18 . This antibody is specifically validated for Western blotting (WB) and immunocytochemistry (ICC) applications .

Monoclonal PRPF18 Antibodies

Monoclonal antibodies target specific epitopes on the PRPF18 protein and derive from single B-cell clones, ensuring consistent specificity across different production lots. The PRPF18 (52) monoclonal antibody from Santa Cruz Biotechnology (catalog number sc-136529) represents a mouse-derived monoclonal antibody that specifically targets amino acids 33-226 of isoform 1 of human PRPF18 . Notably, this antibody does not cross-react with isoform 2 of PRPF18, making it particularly valuable for isoform-specific studies .

Comparative Analysis of Available PRPF18 Antibodies

Table 1 presents a comprehensive comparison of different PRPF18 antibodies currently available for research applications.

Applications of PRPF18 Antibodies

PRPF18 antibodies serve multiple purposes in molecular and cellular biology research, with applications spanning various experimental techniques.

Western Blotting

Western blotting represents one of the primary applications for PRPF18 antibodies, enabling researchers to detect and quantify PRPF18 protein in cell or tissue lysates. Both the polyclonal antibody from antibodies.com and the monoclonal antibody from Santa Cruz Biotechnology are validated for Western blotting applications . For the monoclonal antibody, the recommended starting dilution is 1:200, with a dilution range of 1:100-1:1000 . The PRPF18 protein typically appears at approximately 40 kDa on Western blots .

Immunocytochemistry and Immunofluorescence

Immunocytochemistry and immunofluorescence applications allow visualization of PRPF18 within cellular compartments, confirming its reported nuclear speckle localization. Both the polyclonal antibody from antibodies.com and the monoclonal antibody from Santa Cruz are suitable for these applications . For the monoclonal antibody, the recommended starting dilution for immunofluorescence is 1:50, with a dilution range of 1:50-1:500 .

Immunoprecipitation

Immunoprecipitation techniques are valuable for investigating PRPF18's protein-protein interactions within the spliceosome complex. The monoclonal antibody from Santa Cruz is validated for immunoprecipitation, with a recommended usage of 1-2 μg per 100-500 μg of total protein . This antibody is also available conjugated to agarose specifically for immunoprecipitation applications .

Application-Specific Parameters

Table 2 summarizes the specific application parameters for different PRPF18 antibodies.

Immunogen and Specificity

The specificity and performance characteristics of PRPF18 antibodies directly relate to the immunogens used in their production and their cross-reactivity profiles.

Target Sequences and Immunogens

The polyclonal antibody from Invitrogen was generated using an immunogen sequence corresponding to a specific region of the PRPF18 protein: "SNPVLELELA EEKLPMTLSR QEVIRRLRER GEPIRLFGET DYDAFQRLRK IEILTPEVNK GLRNDLKAAL DKIDQQYLNE IVG" . This detailed sequence information proves valuable for researchers assessing potential cross-reactivity with other proteins or designing blocking experiments to validate antibody specificity.

The polyclonal antibody from antibodies.com was produced using a synthetic peptide corresponding to amino acids 223-268 of human PRPF18 , while the monoclonal antibody from Santa Cruz Biotechnology targets amino acids 33-226 of isoform 1 .

Species Reactivity and Cross-Reactivity

All the PRPF18 antibodies described in the available information demonstrate reactivity with human, mouse, and rat PRPF18 proteins . This cross-species reactivity is supported by the high sequence conservation between human PRPF18 and its mouse and rat orthologs, with up to 100% sequence identity in some regions . This high degree of cross-reactivity makes these antibodies particularly versatile for comparative studies across different mammalian model systems.

Validation and Control Reagents

For validation purposes, a recombinant protein control fragment corresponding to amino acids 62-144 of human PRPF18 is available from Invitrogen . This fragment serves as a valuable tool in blocking experiments with the corresponding antibody (PA5-58031). The recommended protocol involves using a 100x molar excess of the protein fragment control and pre-incubation of the antibody-protein control fragment mixture for 30 minutes at room temperature before application in experimental procedures .

Antibody Formats and Conjugates

The monoclonal antibody from Santa Cruz is available in several formats to accommodate different experimental requirements:

• Unconjugated format (sc-136529)

• Conjugated to agarose for immunoprecipitation applications (sc-136529 AC), with 500 μg/0.25 ml agarose in 1 ml

• Conjugated to HRP for Western blotting, immunohistochemistry, and ELISA applications (sc-136529 HRP), at a concentration of 200 μg/ml

Complementary Research Tools

For use with the PRPF18 polyclonal antibody from antibodies.com, several secondary antibodies are recommended to optimize detection:

• Goat Anti-Rabbit IgG H&L Antibody (AP) (A294874)

• Goat Anti-Rabbit IgG H&L Antibody (Biotin) (A294795)

• Goat Anti-Rabbit IgG H&L Antibody (FITC) (A294887)

• Goat Anti-Rabbit IgG H&L Antibody (HRP) (A294888)

Additionally, the monoclonal antibody from Santa Cruz can be used in conjunction with various RNA interference tools for gene knockdown studies, including:

• PRPF18 siRNA (h): sc-90497

• PRPF18 siRNA (m): sc-152492

• PRPF18 shRNA Plasmid (h): sc-90497-SH

• PRPF18 shRNA Plasmid (m): sc-152492-SH

• PRPF18 shRNA (h) Lentiviral Particles: sc-90497-V

• PRPF18 shRNA (m) Lentiviral Particles: sc-152492-V

These complementary tools expand the experimental possibilities when working with PRPF18 antibodies, enabling more comprehensive studies of PRPF18 function through both detection and functional manipulation approaches.

Research Applications

PRPF18 antibodies serve as valuable tools across numerous research applications focused on RNA processing mechanisms and cellular biology.

Investigation of RNA Splicing Mechanisms

Given PRPF18's critical role in the second step of pre-mRNA splicing, antibodies targeting this protein prove invaluable for investigating splicing mechanisms. Researchers can employ immunoprecipitation techniques using PRPF18 antibodies to isolate and characterize spliceosome complexes, identifying interaction partners and examining the dynamic assembly and disassembly of these critical RNA processing machines.

Analysis of Nuclear Speckle Organization

The localization of PRPF18 to nuclear speckles makes PRPF18 antibodies excellent tools for studying these subnuclear structures. Immunofluorescence microscopy using these antibodies allows researchers to visualize the distribution and dynamics of nuclear speckles under various physiological and experimental conditions, providing insights into the organization of RNA processing centers within the nucleus.

Expression Profiling Across Tissues and Conditions

Western blotting with PRPF18 antibodies enables researchers to examine expression patterns of this protein across different tissues, developmental stages, or disease states. Such analyses may reveal tissue-specific functions or aberrant expression patterns associated with pathological conditions, potentially uncovering new roles for PRPF18 beyond its established function in pre-mRNA splicing.

Isoform-Specific Studies

The availability of antibodies that specifically recognize isoform 1 of PRPF18, such as the monoclonal antibody from Santa Cruz Biotechnology , facilitates studies investigating isoform-specific functions and expression patterns. This specificity allows researchers to distinguish between different splice variants of PRPF18 and examine their potentially distinct roles in cellular processes.