Cell Signaling Technology
XP Monoclonal Antibody

Product Pathways - Cytoskeletal Signaling

ZO-3 (D57G7) XP® Rabbit mAb #3704

Applications Reactivity Sensitivity MW (kDa) Isotype
W IF-IC H Endogenous 140 Rabbit IgG

Applications Key:  W=Western Blotting  IF-IC=Immunofluorescence (Immunocytochemistry)
Reactivity Key:  H=Human
Species cross-reactivity is determined by western blot. Species enclosed in parentheses are predicted to react based on 100% sequence homology.

Protocols

Specificity / Sensitivity

ZO-3 (D57G7) XP® Rabbit mAb detects endogenous levels of total ZO-3 protein.

Source / Purification

Monoclonal antibody is produced by immunizing animals with a synthetic peptide corresponding to carboxy-terminal residues of human ZO-3.

Western Blotting

Western Blotting

Western blot analysis of extracts from MCF-7, HT-29 and HCT-15 cells using ZO-3 (D57G7) XP® Rabbit mAb.

IF-IC

IF-IC

Confocal immunofluorescent analysis of MCF-7 cells using ZO-3 (D57G7) XP® Rabbit mAb (green). Blue pseudocolor = DRAQ5® #4084 (fluorescent DNA dye).

Background

Tight junctions, or zona occludens, form a continuous barrier to fluids across the epithelium and endothelium. They function in regulation of paracellular permeability and in the maintenance of cell polarity, blocking the movement of transmembrane proteins between the apical and the basolateral cell surfaces (reviewed in 1). Zona occludens proteins ZO-1, -2, and -3 (also known as TJP1, 2, and 3) are peripheral membrane adaptor proteins that link junctional transmembrane proteins such as occludin and claudin to the actin cytoskeleton (reviewed in 2). ZO-1 and -2 are required for tight junction formation and function (3,4). In subconfluent proliferating cells, ZO-1 and ZO-2 have been shown to colocalize to the nucleus and play a role in transcriptional regulation, possibly through facilitating nuclear import/export of transcriptional regulators (5-7). The ZO-2 gene is transcribed from two promoters, generating the ZO-2A and ZO-2C isoforms. ZO-2C lacks a 23 amino acid amino-terminal sequence found in other ZO-2 isoforms. While both isoforms appear to be widely expressed, abnormal regulation of the ZO-2 gene may be correlated with development of ductal cancer (8).

Exogenous expression of the amino terminal portion of ZO-3 exerts a dominant negative effect that interferes with assembly of tight junctions and adherens junctions (9). However, additional evidence indicates that tight junctions do form in the absence of ZO-3 protein (10), and that mice lacking ZO-3 appear to develop normally (11).

  1. Shin, K. et al. (2006) Annu Rev Cell Dev Biol 22, 207-35.
  2. Matter, K. and Balda, M.S. (2007) J Cell Sci 120, 1505-11.
  3. Hernandez, S. et al. (2007) Exp Cell Res 313, 1533-47.
  4. Umeda, K. et al. (2006) Cell 126, 741-54.
  5. Betanzos, A. et al. (2004) Exp Cell Res 292, 51-66.
  6. Traweger, A. et al. (2003) J Biol Chem 278, 2692-700.
  7. Huerta, M. et al. (2007) Mol Biol Cell 18, 4826-36.
  8. Chlenski, A. et al. (2000) Biochim Biophys Acta 1493, 319-24.
  9. Wittchen, E.S. et al. (2000) J Cell Biol 151, 825-36.
  10. Adachi, M. et al. (2006) Mol Cell Biol 26, 9003-15.
  11. Xu, J. et al. (2008) Mol Cell Biol 28, 1669-78.

Application References

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Companion Products

For Research Use Only. Not For Use In Diagnostic Procedures.

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