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PR01379

Identifier
CLAUDIN4  [View Relations]  [View Alignment]  
Accession
PR01379
No. of Motifs
3
Creation Date
27-JUL-2000
Title
Claudin-4 signature
Database References
PRINTS; PR01077 CLAUDIN
Literature References
1. TSUKITA, S. AND FURUSE, M.
Occuldin and claudins in tight-junction strands: leading or supporting
players?
TRENDS CELL BIOL. 9 268-273 (1999).
 
2. FURUSE, M., FUJITA, K., HIIRAGI, T., FUJIMOTO, K. AND TSUKITA, S.
Claudin-1 and -2: novel integral membrane proteins localizing at tight 
junctions with no sequence similarity to occludin.
J.CELL BIOL. 141 1539-1550 (1998).
 
3.FURUSE, M., SASAKI, H., FUJIMOTO, K. AND TSUKITA, S.
A single gene product, claudin-1 or -2, reconstitutes tight junction 
strands and recruits occludin in fibroblasts.
J.CELL BIOL. 143 391-401 (1998).
 
4. MORITA, K., FURUSE, M., FUJIMOTO, K. AND TSUKITA, S.
Claudin multigene family encoding four-transmembrane domain protein
components of tight junction strands.
PROC.NATL.ACAD.SCI.U.S.A. 96 511-516 (1999).

Documentation
Tight junctions (TJs) 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 lateral diffusion of membrane lipids and proteins. They also 
act as diffusion barriers within plasma membranes, creating and maintaining
apical and basolateral membrane domains.
 
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 [1]. Immunofluorescence studies have shown that 
claudins are targeted to and incorporated into tight junctions [2]. 
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 [3].
 
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 [2,4]. 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.
 
Claudin-4 was originally termed Clostridium perfringens enterotoxin 
receptor (CPE-R). It was reclassified as claudin-4 on the basis of cDNA 
sequence similarity with claudins-1 and -2, and antibody studies that
showed it to be expressed at tight junctions [4].
 
CLAUDIN4 is a 3-element fingerprint that provides a signature for claudin-4
proteins. The fingerprint was derived from an initial alignment of 3 
sequences: the motifs were drawn from conserved regions within the 
C-terminal two thirds of the alignment, focusing on those sections that 
characterise claudin-4 and distinguish it from other family members - motif
1 lies in the second TM domain; motif 2 resides within the second 
extracellular loop; and motif 3 lies in the cytoplasmic C-terminal region.
A single iteration on SPTR37_10f was required to reach convergence, no 
further sequences being identified beyond the starting set.
Summary Information
3 codes involving  3 elements
0 codes involving 2 elements
Composite Feature Index
3333
2000
123
True Positives
O14493        O19005        O35054        
Sequence Titles
O14493      CPE-RECEPTOR - HOMO SAPIENS (HUMAN).          
O19005 CPE-RECEPTOR - CERCOPITHECUS AETHIOPS (GREEN MONKEY) (GRIVET).
O35054 CPE-RECEPTOR - MUS MUSCULUS (MOUSE).
Scan History
SPTR37_10f 1  300  NSINGLE    
Initial Motifs
Motif 1  width=8
Element Seqn Id St Int Rpt
ALGVLLSV O14493 92 92 -
ALGVLLSV O19005 92 92 -
ALGMLLSV O35054 92 92 -

Motif 2 width=8
Element Seqn Id St Int Rpt
PLVASGQK O14493 150 50 -
PLVASGQK O19005 150 50 -
PMVASGQK O35054 150 50 -

Motif 3 width=10
Element Seqn Id St Int Rpt
AARSAAASNY O14493 199 41 -
AARSAAASNY O19005 199 41 -
AARSVPASNY O35054 200 42 -
Final Motifs
Motif 1  width=8
Element Seqn Id St Int Rpt
ALGVLLSV O14493 92 92 -
ALGVLLSV O19005 92 92 -
ALGMLLSV O35054 92 92 -

Motif 2 width=8
Element Seqn Id St Int Rpt
PLVASGQK O14493 150 50 -
PLVASGQK O19005 150 50 -
PMVASGQK O35054 150 50 -

Motif 3 width=10
Element Seqn Id St Int Rpt
AARSAAASNY O14493 199 41 -
AARSAAASNY O19005 199 41 -
AARSVPASNY O35054 200 42 -