TJP2 Antibody, FITC conjugated
Description
Introduction to TJP2 Antibody, FITC Conjugated
TJP2 (Tight Junction Protein 2) antibody conjugated with fluorescein isothiocyanate (FITC) is a fluorescently labeled reagent used to detect and visualize the TJP2 protein in biological samples. TJP2, also known as Zonula Occludens-2 (ZO-2), is a critical component of tight junctions in epithelial and endothelial cells, regulating cell polarity, barrier function, and signal transduction . The FITC conjugation enables high-sensitivity detection via fluorescence-based techniques such as flow cytometry, immunofluorescence (IF), and immunohistochemistry (IHC) .
Key Features of FITC-Conjugated TJP2 Antibody
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Target: Human, mouse, and rat TJP2 protein (cross-reactive) .
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Conjugate: FITC (excitation/emission maxima at ~498 nm/~519 nm) .
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Recommended Applications: Flow cytometry, IF, IHC, Western blot (WB) .
FITC Conjugation Process
FITC binds to lysine residues on the antibody via primary amine groups. Optimal conjugation ratios (typically 3–6 FITC molecules per antibody) balance brightness and solubility while avoiding quenching . Critical steps include:
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Sodium Azide Removal: Residual sodium azide inhibits FITC conjugation .
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Titration Optimization: Testing FITC:antibody ratios (e.g., 10–400 µg FITC per mg antibody) ensures optimal signal-to-noise .
Validation and Performance Data
| Cell Line | Treatment | Whole-Cell FI | Cytoplasmic FI | Membrane FI |
|---|---|---|---|---|
| PC-1.0 (invasive) | None | 1160.7 ± 259.1 | 3273.7 ± 131.2 | 69.5 ± 38.0 |
| PC-1.0 | U0126 (MEK inhibitor) | 1009.4 ± 257.8 | 2814.8 ± 297.0 | Increased membrane localization |
| PC-1 (non-invasive) | DF-CM (dissociation factor) | 182.3 ± 48.2 | 52.1 ± 16.4 | Disrupted membrane localization |
Role in Disease Pathogenesis
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Progressive Familial Intrahepatic Cholestasis (PFIC): Biallelic TJP2 variants (e.g., c.1202A>G, c.2668-11A>G) disrupt cytoskeletal regulation, contributing to PFIC type 4 .
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Pancreatic Cancer Metastasis: TJP2 expression correlates with cell dissociation; U0126 treatment restores membrane localization in invasive PC-1.0 cells .
Functional Insights from Knockdown Studies
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siRNA Knockdown: Reduces cell proliferation, induces apoptosis, and disrupts F-actin organization in LO2/HepG2 cells.
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Gene Expression Profiling: Downregulates microtubule cytoskeleton pathways, linking TJP2 to structural integrity.
Technical Considerations
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Photostability: FITC’s moderate photostability makes it suitable for short-duration imaging; alternatives like Cyanine 5.5 are preferable for prolonged exposure .
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Multiplexing Compatibility: Pair with TRITC or Cy3 for dual-target detection .
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Storage: Lyophilized antibodies retain stability; reconstitute in PBS for immediate use .
Product Specs
Constituents: 50% Glycerol, 0.01M PBS, pH 7.4
Target Background
- Biochemistry and microscopy studies in T cells have confirmed the PDZ-dependent interaction between SNX27 and ZO-2. These studies have demonstrated the role of this interaction in controlling the dynamic localization of ZO-2 at the immunological synapse. PMID: 28477369
- A significant percentage (61%) of cases of cholestatic liver disease involve a likely causal mutation spanning numerous genes, including TJP2 and VIPAS39, which are rarely reported as causes of this condition. PMID: 28039895
- Research indicates the modular and supramodular organization of zonula occludens protein 2 (ZO-2), enabling it to interact with a wide array of molecules, including cell-cell adhesion proteins, cytoskeletal components, and nuclear factors. PMID: 28415133
- Data has identified two disease-causing genes, TJP2 and GJB2, in a Chinese family with autosomal dominant nonsyndromic hereditary hearing impairment. PMID: 26668150
- TJP2 deficiency may predispose individuals to hepatocellular carcinoma in early childhood. PMID: 25921221
- Claudin-19, the most abundant claudin in myelin, does not exhibit binding to ZO2. PMID: 25712527
- JAM-A regulates epithelial permeability through its association with ZO-2, afadin, and PDZ-GEF1, leading to the activation of Rap2c and control over the contraction of the apical cytoskeleton. PMID: 23885123
- Protein-truncating mutations in the tight junction protein 2 gene disrupt protein localization and tight-junction structure, resulting in severe cholestatic liver disease. PMID: 24614073
- Studies have shown that ZO-2 inhibition increases the invasive and migratory capacities of invasive tumor cells. This is associated with an increase in MT1-MMP. PMID: 23605953
- The Alu-related transcript of the TJP2 gene (TJP2-Alu transcript) has been found to be differentially expressed between colorectal tumor and normal tissues, suggesting its potential as a diagnostic marker for colorectal cancer. PMID: 23612256
- ZO-2 inhibits the Wnt signaling pathway, reduces cell proliferation, and promotes apoptosis. Its absence, mutation, or overexpression is associated with various human diseases, including deafness and cancer. PMID: 22671599
- AmotL1 and ZO-2 are potential targets for controlling the oncogenic function of YAP. PMID: 21685940
- These findings suggest the involvement of a ZO-2 tight junction independent signaling complex containing Jak1 and uPAR in vascular smooth muscle cell intercellular communications. PMID: 21679692
- ZO-2 interacts with YAP2 to form a complex. ZO-2 facilitates both the nuclear translocation of YAP2 and its pro-apoptotic function. The YAP2/ZO-2 complex appears to play a role in cell detachment. PMID: 20868367
- The identification of ZASP helps to elucidate the complex nuclear molecular arrays that form on ZO-2 scaffolds. PMID: 20868680
- The first PDZ domain of zona occludens-1 (ZO-1) and 2 (ZO-2) interacts with the carboxy-terminal PDZ binding motif of TAZ. PMID: 20850437
- TJP2- and GSK-3beta-mediated increased susceptibility to apoptosis of cells in the inner ear is the mechanism for adult-onset hearing loss in this kindred and may serve as a model for age-related hearing loss in the general population. PMID: 20602916
- Research shows that ZO isoforms bind PtdInsPs and provides an alternative regulatory mechanism for the formation and stabilization of protein complexes in the nucleus. PMID: 19784548
- Familial hypercholanemia in Amish individuals is associated with mutations in tight junction protein 2 (encoded by TJP2, also known as ZO-2) and bile acid Coenzyme A: amino acid N-acyltransferase (encoded by BAAT). PMID: 12704386
- Sertoli cells associated with carcinoma in situ of the testicles exhibit an altered distribution of ZO-2 and loss of blood-testis barrier function. PMID: 17217619
- TJP2 did not reveal a otosclerosis-causing mutation. PMID: 18224337
- Upregulation of ZO-2 by Angiopoietin-1 reduces vascular endothelial growth factor-induced brain endothelial permeability. PMID: 19148554
- Structural comparison indicates that the ZO-2 PDZ2 homodimer may have a similar ligand-binding pattern to the ZO-1 PDZ2-connexin 43 complex. PMID: 19342771
- The tight junction protein ZO-2 is involved in the regulation of vascular smooth muscle cell growth control upon vascular injury, mediated by the transcription factor Stat1. PMID: 19380416
- ZO-2 may serve to anchor regulatory proteins at gap junctions composed of Cx36. PMID: 19418635
