Protein Domain : IPR017974

Type:  Conserved_site Name:  Claudin, conserved site
Description:  Zona occludens (ZO), or tight junctions (TJ), are specialised membrane domains found at the most apical region of polarised epithelial and endothelial cells. They create a primary barrier, preventing paracellular transport of solutes, and restricting the lateral diffusion of membrane lipids and proteins, thus maintaining cellular polarity []. They also act as diffusion barriers within plasma membranes, creating and maintaining apical and basolateral membrane domains. Under freeze-fracture electron microscopy, TJs appear as a network of continuous anastomosing intramembranous strands. These strands consist mainly of claudins and occludin (), which are transmembrane proteins that polymerise within plasma membranes to form fibrils [].Recently, the molecular architecture of tight junctions has begun to be elucidated. One group of proteins thought to be major components of TJs is the claudin family []. Immunofluorescence studies have shown that claudins are targeted to and incorporated into tight junctions []. Furthermore, when claudins are introduced into cells that lack tight junctions, networks of strands and grooves form at cell-cell contact sites that closely resemble native TJs [].The claudin protein family is encoded by at least 17 human genes, with many homologues cloned from other species. Tissue distribution patterns for the claudin family members are distinct. Claudin-1 and -2, for example, are expressed at high levels in the liver and kidney, whereas claudin-3 mRNA is detected mainly in the lung and liver [, ]. This suggests that multiple claudin family members may be involved in tight junction strand formation in a tissue-dependent manner. Hydropathy analysis suggests that all claudins share a common transmembrane (TM) topology. Each family member is predicted to possess four TM domains with intracellular N and C termini. Although their C-terminal cytoplasmic domain sequences vary, most claudin family members share a common motif of -Y-V in this region. This has been postulated as a possible binding motif for PDZ domains of other tight junction-associated membrane proteins, such as ZO-1 ().This entry represents a conserved region located in an extracellular loop between the first and second transmembrane regions. Short Name:  Claudin_CS
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0 Child Features

0 Contains

1 Cross References

Identifier
PS01346

17 Found Ins

DB identifier Type Name
IPR004031 Family PMP-22/EMP/MP20/Claudin superfamily
IPR006187 Family Claudin
IPR013287 Family Claudin-12
IPR003548 Family Claudin-1
IPR003549 Family Claudin-3
IPR003550 Family Claudin-4
IPR003551 Family Claudin-5
IPR003552 Family Claudin-7
IPR003553 Family Claudin-9
IPR003554 Family Claudin-10
IPR003555 Family Claudin-11
IPR003556 Family Claudin-14
IPR003925 Family Claudin-6
IPR003926 Family Claudin-8
IPR003927 Family Claudin-16
IPR003928 Family Claudin-18
IPR008094 Family Claudin-15

2 GO Annotations

GO Term Gene Name
GO:0005198 IPR017974
GO:0005923 IPR017974

2 Ontology Annotations

GO Term Gene Name
GO:0005198 IPR017974
GO:0005923 IPR017974

0 Parent Features

0 Proteins

5 Publications

First Author Title Year Journal Volume Pages PubMed ID
            10370242
            9647647
            9892664
            9786950
            11283726