APLP2 (Ab-755) Antibody
Description
Introduction
The APLP2 (Ab-755) Antibody is a rabbit polyclonal antibody specifically designed to target the Amyloid-like protein 2 (APLP2), a key protein involved in cellular processes such as glucose homeostasis, cell proliferation, and immune regulation. This antibody is optimized for Western blotting (WB) and is widely used in research to study APLP2’s role in diseases like pancreatic cancer and its interaction with MHC class I molecules .
Pancreatic Cancer Studies
The APLP2 (Ab-755) Antibody has been instrumental in identifying APLP2’s role in pancreatic cancer. Studies using this antibody demonstrated that APLP2 C-terminal fragments are abundant in pancreatic cancer cells and that β-secretase inhibitors targeting APLP2 cleavage reduce tumor cell viability . This highlights APLP2 as a potential therapeutic target in oncology.
MHC Class I Regulation
Research employing this antibody revealed that APLP2 binds to MHC class I molecules (e.g., Kd) at the cell surface, promoting their endocytosis and lysosomal degradation. Overexpression of APLP2 reduces MHC class I surface expression, with implications for immune evasion in cancer .
Cellular Trafficking Mechanisms
The antibody has been used to study APLP2’s internalization via clathrin-dependent pathways. Mutations in APLP2’s cytoplasmic tail disrupted its interaction with adaptor proteins, impairing its ability to regulate MHC class I trafficking .
Pricing and Availability
| Catalog Number | Package Size | Price | Shipping |
|---|---|---|---|
| A41342 | 50 µl | $275 | $40 (St. Louis, MO) |
| A41342 | 100 µl | $275 |
Product Specs
Target Background
- APLP2 expression may correlate with tumor development and serve as a prognostic indicator for patients with glioblastoma. PMID: 29663738
- Studies suggest that the combined signature of APLP2, RRM2, and PRC1 could be useful for differentiating between benign (follicular adenoma) and malignant (follicular carcinoma and follicular variant of papillary carcinoma) tumors of the thyroid follicular epithelium. PMID: 27796194
- Research demonstrates a significant role for APLP2 in refractive development in mice and humans, suggesting a high degree of evolutionary conservation in the signaling pathways underlying refractive eye development. PMID: 26313004
- Evidence indicates elevated APLP2 expression in pancreatic cancer metastases. PMID: 25576918
- Data suggest that PCSK9 enhances LDLR degradation independently of APLP2 or sortilin, both ex vivo and in mice. PMID: 26085104
- Findings establish a role for APLP2 in the growth of pancreatic cancer cells and demonstrate that inhibitors preventing APLP2 cleavage reduce the viability of these cells. PMID: 22797723
- Studies indicate that amyloid precursor protein-like protein-2, but not amyloid precursor protein, participates in mediating the postendocytic delivery of PCSK9 to lysosomes, thereby playing a crucial role in PCSK9 function. PMID: 23430252
- Aberrant enhancement of YWK-II/APLP2 through the nuclear export of Bat3 may contribute to cancer development by inhibiting cell apoptosis. PMID: 22641691
- APP and its mammalian homologs, amyloid precursor-like proteins APLP1 and APLP2, participate in synaptogenesis via trans-cellular dimerization under physiological conditions. PMID: 21952790
- APLP-2 (and APLP1) possess the ability to activate gene transcription by binding to Mint3. PMID: 21178287
- APLP2 regulates the expression of major histocompatibility complex class I molecules on cancer cells. PMID: 21826533
- The interaction between APLP2 and ataxin-7, along with the proteolytic processing of APLP2, may contribute to the pathogenesis of spinocerebellar ataxia type 7. PMID: 20732423
- APLP1 and APLP2 undergo processing by gamma-secretase in a Presenilin 1-dependent manner, leading to the production of extreme carboxyl-terminal fragments (APP-like Intracellular Domain) that enhance Fe65-dependent gene activation. PMID: 12228233
- Crystals of the extracellular fragment X3 of a human sperm membrane protein YWK-II/APPH have been grown using the vapor-diffusion method. PMID: 12595709
- Sustained levels of APP and elevated levels of APLP2, despite reduced mRNA expression, are attributed to altered proteolytic processing of these proteins. PMID: 14597230
- While the APLP2 gene lacks a CAGA box, it contains a GAGA sequence in a location similar to the CAGA box found in the APP gene. PMID: 15208260
- Human and murine Abeta peptides, Abeta40 and Abeta42, interact with each other. Interspecies Abeta aggregates and fibers readily form and exhibit greater stability compared to homogenous human fibers. PMID: 15584916
- APLP2 is shed by disintegrins and metalloproteinases. Overexpression of secretase or TACE in HEK293 cells significantly increases the release of neurotrophic soluble APLP2. PMID: 16279945
- Findings indicate an increase in the immunoreactivity of the nuclear C-terminal fragments of APLP2 and GSK-3beta in the brains of Alzheimer's disease patients. PMID: 16645641
- APLP2 and APP play roles in sperm function. PMID: 17405931
- YWK-II (APLP2 protein) functions as a G(o)-coupled receptor for Mullerian inhibiting substance in mediating ERK1/2 activation, leading to anti-apoptotic activity or cell survival. PMID: 17452623
- The association of APLP2/MHC is influenced by multiple domains of the MHC class I heavy chain and the effects of beta(2)m on the conformation of the heavy chain. PMID: 18452037
- APLP2 modulates the stability and endocytosis of K(d) molecules. PMID: 18641335
- APLP2 exhibits a multistep trafficking function that influences the expression of major histocompatibility complex class I molecules at the plasma membrane. PMID: 19808674
Q&A
What is APLP2 and what are its main biological functions?
APLP2 (Amyloid-like protein 2) is a member of the amyloid precursor protein family with multiple biological functions. According to research, APLP2 plays significant roles in the regulation of hemostasis, with its soluble form potentially exhibiting inhibitory properties toward coagulation factors. Additionally, APLP2 interacts with cellular G-protein signaling pathways and may bind to specific DNA sequences such as 5'-GTCACATG-3' (CDEI box). The protein has demonstrated inhibitory effects on several proteases including trypsin, chymotrypsin, plasmin, factor XIA, and plasma and glandular kallikrein. APLP2 also participates in modulating the Cu/Zn nitric oxide-catalyzed autodegradation of GPC1 heparan sulfate side chains in fibroblasts . Recent studies have shown APLP2's involvement in regulating MHC class I molecule expression, particularly affecting cell surface presentation of various mouse MHC class I allotypes .
What species reactivity has been confirmed for APLP2 (Ab-755) antibody?
The APLP2 (Ab-755) antibody has been validated for reactivity with multiple species, making it versatile for comparative studies. According to product specifications, the antibody has confirmed reactivity with:
Western blot validation has been performed on human cell lines (SH-SY5Y, HepG2, HeLa) and brain tissue lysates from both mouse and rat, confirming specific detection of APLP2 across these species . While some researchers have inquired about potential cross-reactivity with zebrafish tissues, as indicated in customer questions, this application has not been officially validated but might be possible due to protein conservation across species .
How does APLP2 interact with MHC class I molecules and what factors influence this association?
APLP2 demonstrates variable binding affinity to different MHC class I molecules, with this interaction influenced by multiple factors. Research has shown that APLP2 binds to several mouse MHC class I allotypes with different strengths, not limited to Kᵈ as initially thought . The interaction between APLP2 and MHC class I molecules is dependent on:
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The conformation of the MHC molecule - APLP2 specifically binds to MHC molecules with properly folded outer domains (α1α2 region).
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The α3/transmembrane/cytoplasmic regions - suggesting that both conserved and polymorphic regions of MHC molecules participate in the interaction.
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β2-microglobulin (β2m) presence - human β2m transfection increases the association of APLP2 with mouse MHC class I molecules by affecting the conformation of MHC class I heavy chains .
Intracellular localization studies have revealed that while APLP2 associates with both Kᵈ and Lᵈ in the Golgi apparatus, it associates with Kᵈ in additional intracellular vesicular structures, indicating allotype-specific trafficking patterns . This differential binding and co-localization suggests APLP2 may regulate MHC class I molecules in an allotype-dependent manner, potentially affecting antigen presentation pathways.
What is the significance of the tyrosine 755 phosphorylation site targeted by the Ab-755 antibody?
The APLP2 (Ab-755) antibody specifically targets the region around the tyrosine 755 phosphorylation site (P-T-Y-K-Y) of human APLP2 . This region is of particular interest because:
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Phosphorylation of tyrosine residues often serves as a molecular switch in signaling pathways
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The antibody was generated using a non-phosphopeptide derived from this region, allowing detection of total APLP2 protein regardless of phosphorylation status
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The conservation of this region across species (human, mouse, rat) suggests functional importance
The specificity for this region enables researchers to detect endogenous levels of total APLP2 protein , making it valuable for studying APLP2 expression across different cell types and experimental conditions. While the specific functional consequences of phosphorylation at this site are not fully detailed in the provided references, the development of an antibody targeting this region suggests it may play an important role in APLP2's cellular functions, potentially affecting its interactions with other proteins or its subcellular localization.
How does APLP2 expression vary across different tissues and cell lines?
APLP2 expression demonstrates tissue and cell-type specificity, which is important to consider when designing experiments. Based on the available data:
The high expression in brain tissue across species suggests important neurological functions for APLP2, while its presence across diverse cell types indicates broader physiological roles. Customer inquiries about ovary expression indicate researchers' interest in reproductive biology applications. When designing experiments, researchers should consider these expression patterns to select appropriate positive controls and experimental systems.
What are the optimal conditions for Western blot applications using APLP2 (Ab-755) antibody?
For optimal Western blot results with APLP2 (Ab-755) antibody, the following protocol parameters have been validated:
Following these validated conditions will help ensure specific detection of APLP2 protein at the expected molecular weight range of 100-110 kDa . Researchers should optimize these conditions for their specific experimental systems, particularly when working with tissues or cell lines where APLP2 expression may vary.
Besides Western blot, what other applications have been validated for APLP2 (Ab-755) antibody?
While Western blot is the most thoroughly validated application for APLP2 (Ab-755) antibody, additional applications have been reported:
Researchers interested in applications beyond Western blot should conduct preliminary validation studies to optimize conditions for their specific experimental systems. The high sensitivity reported for ELISA applications (1:40000 dilution) suggests this antibody may be valuable for quantitative analyses of APLP2 expression across different experimental conditions or sample types.
What are the recommended storage and handling conditions for maintaining antibody activity?
Proper storage and handling of the APLP2 (Ab-755) antibody is crucial for maintaining its activity and specificity. The following recommendations have been provided:
For optimal antibody performance, it is recommended to aliquot the antibody upon receipt to minimize freeze-thaw cycles . When working with lyophilized antibody, reconstitution should be performed according to manufacturer's instructions, typically with sterile water or buffer. Proper storage and handling will help ensure consistent experimental results and extend the usable life of the antibody.
How can researchers validate the specificity of APLP2 (Ab-755) antibody in their experimental system?
Validating antibody specificity is crucial for ensuring reliable experimental results. For APLP2 (Ab-755) antibody, several approaches can be employed:
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Positive controls: Include brain tissue lysates (mouse or rat) or SH-SY5Y/HepG2/HeLa cell lysates, which have demonstrated APLP2 expression .
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Blocking peptide validation: Some suppliers provide blocking peptides for APLP2 antibodies, as mentioned in customer Q&A . Pre-incubation of the antibody with this peptide should abolish specific signals in Western blot.
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Molecular weight verification: Confirm detection of bands at the expected molecular weight range (theoretical: 87 kDa; observed: 100-110 kDa) .
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Knockdown/knockout validation: APLP2 knockdown or knockout samples provide the most stringent specificity control, though this requires additional experimental setup.
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Cross-species validation: The antibody's reactivity across human, mouse, and rat samples can be leveraged to confirm consistent detection patterns.
When interpreting results, researchers should be aware that post-translational modifications may affect the observed molecular weight of APLP2 and that expression levels vary across tissues and cell types.
What are common challenges in APLP2 detection and how can they be addressed?
Researchers may encounter several challenges when working with APLP2 (Ab-755) antibody:
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Molecular weight discrepancy: The observed molecular weight (100-110 kDa) differs from the theoretical weight (87 kDa) . This is likely due to post-translational modifications and should not be interpreted as non-specific binding.
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Variable expression levels: APLP2 expression varies across tissues and cell types. For low-expressing samples, increased loading amount, longer exposure times, or more sensitive detection methods may be necessary.
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Background signals: Optimization of blocking conditions (5% non-fat milk/TBS for 1.5 hours at RT) and antibody dilutions (typically 1:500-1:3000 for Western blot) is important to minimize non-specific background .
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Cross-reactivity concerns: While the antibody has been validated for human, mouse, and rat samples, researchers working with other species (e.g., zebrafish, as mentioned in customer inquiries) should perform additional validation.
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Buffer compatibility: Some experiments may require BSA-free antibody preparations, as indicated by customer questions . In such cases, researchers should contact manufacturers regarding availability of alternative formulations.
Addressing these challenges through careful experimental design and optimization will help ensure reliable and reproducible results when studying APLP2 expression and function.
How can researchers analyze APLP2's interaction with MHC class I molecules using this antibody?
To investigate APLP2's interaction with MHC class I molecules, researchers can employ several approaches using the APLP2 (Ab-755) antibody:
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Co-immunoprecipitation (Co-IP):
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Immunoprecipitate MHC class I molecules and probe for APLP2 using the antibody in Western blot
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Alternatively, immunoprecipitate APLP2 and probe for MHC class I molecules
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Include appropriate controls (IgG control, β2m-deficient samples)
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Subcellular co-localization:
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Expression correlation:
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Analyze how APLP2 expression levels correlate with cell surface MHC class I expression using flow cytometry in combination with Western blot
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β2m dependence:
When interpreting results, researchers should consider that:
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The interaction depends on proper folding of MHC class I outer domains
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Multiple domains of the MHC class I heavy chain contribute to the interaction
This methodological approach will help elucidate the molecular mechanisms and functional consequences of APLP2's interaction with MHC class I molecules in different cellular contexts.
What are emerging areas of investigation for APLP2 function beyond current applications?
While APLP2's interactions with MHC class I molecules and its role in various biochemical processes have been established, several promising research directions are emerging:
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Neurological functions: Given APLP2's high expression in brain tissue and its relationship to the amyloid precursor protein family, further investigation into its role in neurological development and disease is warranted.
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Reproductive biology: Customer inquiries about APLP2 expression in ovarian tissue suggest interest in reproductive functions that remain to be fully characterized.
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Immune regulation: The interaction with MHC class I molecules indicates potential roles in immune recognition and regulation that could be explored in various disease models.
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Post-translational modifications: The discrepancy between theoretical and observed molecular weights suggests extensive modifications that may regulate APLP2 function and could be characterized using phospho-specific antibodies.
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Therapeutic targeting: Understanding APLP2's precise functions could reveal opportunities for therapeutic intervention in conditions where its activity is dysregulated.
Future studies combining genetic, biochemical, and cellular approaches with APLP2-specific antibodies will help elucidate these unresolved questions and potential applications.
How might phosphorylation at tyrosine 755 affect APLP2 function?
The APLP2 (Ab-755) antibody targets the region around the tyrosine 755 phosphorylation site , but the functional significance of phosphorylation at this specific residue remains an area for investigation:
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Signaling pathway regulation: Tyrosine phosphorylation often serves as a molecular switch in signaling cascades. Researchers could investigate which kinases and phosphatases regulate phosphorylation at this site and what downstream pathways are affected.
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Protein-protein interactions: Phosphorylation may create or disrupt binding sites for interacting proteins. Using phospho-mimetic mutants (Y755E) or phospho-null mutants (Y755F) could help identify phosphorylation-dependent interactions.
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Subcellular localization: Phosphorylation might affect APLP2's trafficking between cellular compartments, potentially explaining its varied co-localization with different MHC class I molecules .
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Structural effects: Phosphorylation could induce conformational changes affecting APLP2's function, such as its inhibitory properties toward proteases or its DNA-binding capability .
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Cross-talk with other modifications: The relationship between phosphorylation at tyrosine 755 and other post-translational modifications on APLP2 could reveal complex regulatory mechanisms.
Investigating these aspects would significantly advance our understanding of APLP2 regulation and function, potentially revealing new therapeutic targets in conditions where APLP2 activity is altered.
