Protein-binding domains of the tight junction protein, ZO-2, are highly conserved between avian and mammalian species

Biochem Biophys Res Commun. 1998 Nov 27;252(3):617-22. doi: 10.1006/bbrc.1998.9710.


The tight junction is composed of many proteins and includes three members of the MAGUK (membrane-associated, guanylate kinase-like) protein family: ZO-1, ZO-2, and ZO-3. ZO-2 was cloned and sequenced from embryonic chicken retina. Antibodies against a short ZO-2 peptide immunolabeled the outer limiting membrane (an adherens junction of the neural retina) and the apical junctional complexes of the retinal pigment epithelium. Each ZO family member contains a homologous series of protein-binding domains: three distinct PDZ domains and src homology 3 (SH3), guanylate kinase-like (GuK), and acidic domains. Compared with human and canine ZO-2s, the PDZ and SH3 domains are the most conserved (90-95% amino acid sequence identity). These domains are only 50-71% identical with the homologous domains of ZO-1 and ZO-3. Although the sequence is less conserved for regions that link the protein-binding domains, the length of those regions is conserved in ZO-2s. The postacidic (C-terminal) region is the least conserved. The evolutionary pressure to maintain the sequence of the protein-binding domains suggests that homologous domains have different functions in ZO-1, ZO-2, and ZO-3.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Carrier Proteins / chemistry
  • Chick Embryo
  • Conserved Sequence
  • Dogs
  • Humans
  • Membrane Proteins / chemistry*
  • Molecular Sequence Data
  • Phosphoproteins / chemistry
  • Polymerase Chain Reaction
  • Protein Binding
  • Zonula Occludens Proteins
  • Zonula Occludens-1 Protein
  • Zonula Occludens-2 Protein


  • Carrier Proteins
  • Membrane Proteins
  • Phosphoproteins
  • TJP1 protein, human
  • TJP2 protein, human
  • TJP3 protein, human
  • Zonula Occludens Proteins
  • Zonula Occludens-1 Protein
  • Zonula Occludens-2 Protein

Associated data

  • GENBANK/AF085184