TPC1 Antibody
Description
Definition and Function
TPC1 antibodies are immunological tools used to study the localization, expression, and interactions of TPC1 in cellular and tissue models. These antibodies bind specifically to epitopes on the TPC1 protein, enabling detection via techniques such as:
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Western blot (WB)
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Immunohistochemistry (IHC)
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Immunofluorescence (IF/ICC)
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ELISA
The antibody’s epitope is typically derived from conserved regions of TPC1, ensuring cross-reactivity with human, mouse, and rat orthologs .
Applications in Research
TPC1 antibodies have been employed in diverse studies to elucidate TPC1’s role in cellular processes:
Cross-Reactivity and Species Specificity
TPC1 antibodies exhibit broad species compatibility due to conserved TPC1 sequences across mammals:
| Species | Reactivity | Applications Validated |
|---|---|---|
| Human | High | WB, IHC, IF/ICC |
| Mouse | High | WB, IHC, IF/ICC |
| Rat | Moderate | WB, IHC |
Note: Reactivity may vary depending on the antibody’s immunogen and host species (e.g., rabbit vs. mouse) .
TPC1 Localization in Endosomal Compartments
TPC1 antibodies revealed its predominant localization to early and recycling endosomes in HeLa cells and murine macrophages. Co-localization with markers (e.g., Rab4, Rab11) confirmed its role in Ca²⁺-regulated vesicle fusion .
TPC1’s Role in Mast Cell Function
In TPC1-deficient mice, antibodies were used to verify knockout efficiency and study mast cell degranulation:
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Reduced Mast Cell Numbers: Peritoneal mast cells were halved in Tpc1−/− mice .
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Enhanced Anaphylaxis: TPC1 knockout led to amplified histamine release and delayed recovery in systemic anaphylaxis models .
| Parameter | Wild-Type (Tpc1+/+) | TPC1-Deficient (Tpc1−/−) |
|---|---|---|
| Body Temperature Drop (°C) | ~1.0 | ~2.0 |
| Mast Cell Percentage | 4.78% | 2.01% |
| Recovery Time | 2 hours | Prolonged (hours) |
Interactions with Syntaxins
Proteomic studies using TPC1 antibodies identified syntaxins 7, 8, and 12 as direct binding partners, suggesting TPC1’s involvement in SNARE-mediated vesicle fusion .
Table 1: Antibody Performance in Immunohistochemistry
| Tissue | Antigen Retrieval | Primary Antibody Dilution | Signal Quality |
|---|---|---|---|
| Mouse Heart | TE buffer (pH 9.0) | 1:50–1:500 | Strong |
| Rat Aorta Smooth Muscle | Citrate buffer (pH 6.0) | 1:50–1:500 | Moderate |
Table 2: TPC1 Antibody Limitations
Product Specs
Constituents: 50% Glycerol, 0.01M PBS, pH 7.4
Target Background
- Structural basis for activation of voltage sensor domains in an ion channel TPC1. PMID: 30190435
- The variant (TPC1D454N) depolarizes endomembranes by increasing cation fluxes towards the cytosol PMID: 28885692
- The ion selectivity of AtTPC1 was determined and compared with the selectivity of human TPC2. TPC1 exhibits selectivity for Ca(2+) over Na(+), but is nonselective among monovalent Li(+), Na(+), and K(+)). AtTPC1 can be converted to a Na(+)-selective channel by mimicking the selectivity filter of HsTPC2. Key residues were identified in the TPC filters that differentiate this selectivity. A Na+-selective mutant was characterized. PMID: 28096396
- TPC1 plays a role in the systemic response to salt stress PMID: 27261066
- Structure-function analysis of the Arabidopsis TPC1 channel in planta confirmed that helix S10 serves as the primary voltage-sensing site, with Glu450 and Glu478 identified as possible ion-pair partners for voltage-sensing Arg537. PMID: 27270880
- The domain architecture of TPC1 has been discussed. PMID: 27156118
- This study revealed that the dimerization of a predicted helix within the carboxyl-terminus is essential for the activity of TPC1. PMID: 26781468
- The crystal structure of TPC1 from Arabidopsis thaliana at 2.87 A resolution provides a foundation for understanding ion permeation, channel activation, the location of voltage-sensing domains and regulatory ion-binding sites. PMID: 26961658
- The crystal structure of a vacuolar two-pore channel from Arabidopsis thaliana, AtTPC1, has been determined, revealing its function as a homodimer. PMID: 26689363
- The SV channel fou2 mutation in TCP1 altered sensitivity to luminal Ca2+ levels. PMID: 19298454
- TPC1 contains a N-terminal dileucine motif (EDPLI) critical for vacuolar targeting. PMID: 22490017
- TPC1 plays a role in maintaining differential K and Ca storage across the leaf; it releases Ca2+ from epidermal and bundle sheath cell vacuoles to maintain low [Ca]vac. PMID: 22067997
- EF-hand 1 modulates the Ca2+-sensitivity of TPC1, while EF-hand 2 is essential for the Ca2+-dependent channel opening. PMID: 21736651
- Results indicate that Glu-450 and Asp-454 of the slow vacuolar channel TPC1 are directly involved in Ca2+ binding, whereas Glu-456 and Glu-457 likely play a role in connecting the luminal Ca2+ binding site to the channel gate. PMID: 21764990
- AtTPC1 functions in response to external Ca2+ but not to abscisic acid and methyl jasmonate in Arabidopsis guard cells. PMID: 20061305
- Findings suggest that members of the TPC1 channel family are reactive oxygen species-responsive calcium channels and may be the targets of aluminum-dependent inhibition. PMID: 15464979
- A tpc1 knockout mutant lacks functional slow vacuolar channel activity and exhibits defects in both abscisic acid-induced repression of germination and the response of stomata to extracellular calcium. PMID: 15772667
- A genetic screen designed to identify misregulated activity of 13-lipoxygenase revealed a missense mutation in TPC1, suggesting that cation fluxes regulate a positive feedback loop for jasmonic acid synthesis. PMID: 17253984
- Results indicate that wild-type TPC1 contributes to the expression of PDF1.2a and THI2 through mechanisms distinct from those affecting their expression in fou2. PMID: 17981874
- A study found that the loss of TPC1 did not alter membrane hyperpolarization-activated Ca(2+)-permeable channel activity. We conclude that TPC1, under physiological conditions, functions as a vacuolar cation channel without significantly impacting cytosolic Ca(2+) homeostasis. PMID: 18028262
