MAGUK proteins: structure and role in the tight junction

2000 ◽  
Vol 11 (4) ◽  
pp. 315-324 ◽  
Author(s):  
Lorenza González-Mariscal ◽  
Abigail Betanzos ◽  
Antonia Ávila-Flores
Keyword(s):  
Tight Junction ◽  
Maguk Proteins

scholarly journals The Unique-5 and -6 Motifs of ZO-1 Regulate Tight Junction Strand Localization and Scaffolding Properties

2007 ◽  
Vol 18 (3) ◽  
pp. 721-731 ◽  
Author(s):  
Alan S. Fanning ◽  
Brent P. Little ◽  
Christoph Rahner ◽  
Darkhan Utepbergenov ◽  
Zenta Walther ◽  
...  
Keyword(s):  
Tight Junction ◽  
Tight Junctions ◽  
Cultured Cells ◽  
Variable Region ◽  
Binding Studies ◽  
Vitro Binding ◽  
Complex Protein ◽  
Regulatory Functions ◽  
Maguk Proteins

The proper cellular location and sealing of tight junctions is assumed to depend on scaffolding properties of ZO-1, a member of the MAGUK protein family. ZO-1 contains a conserved SH3-GUK module that is separated by a variable region (unique-5), which in other MAGUKs has proven regulatory functions. To identify motifs in ZO-1 critical for its putative scaffolding functions, we focused on the SH3-GUK module including unique-5 (U5) and unique-6 (U6), a motif immediately C-terminal of the GUK domain. In vitro binding studies reveal U5 is sufficient for occludin binding; U6 reduces the affinity of this binding. In cultured cells, U5 is required for targeting ZO-1 to tight junctions and removal of U6 results in ectopically displaced junction strands containing the modified ZO-1, occludin, and claudin on the lateral cell membrane. These results provide evidence that ZO-1 can control the location of tight junction transmembrane proteins and reveals complex protein binding and targeting signals within its SH3-U5-GUK-U6 region. We review these findings in the context of regulated scaffolding functions of other MAGUK proteins.

The Nature of the Intramembrane Particle

1980 ◽  
Vol 38 ◽  
pp. 688-691
Author(s):  
A.J. Verkleij
Keyword(s):  
Escherichia Coli ◽  
Tight Junction ◽  
Gap Junction ◽  
The Other ◽  
Fracture Face ◽  
Band 3 Protein ◽  
Satisfactory Explanation ◽  
Freeze Fracturing ◽  
Intramembrane Particle ◽  
Luminal Membrane

Freeze-fracturing splits membranes into two helves, thus allowing an examination of the membrane interior. The 5-10 rm particles visible on both monolayers are widely assumed to be proteinaceous in nature. Most membranes do not reveal impressions complementary to particles on the opposite fracture face, if the membranes are fractured under conditions without etching. Even if it is considered that shadowing, contamination or fracturing itself might obscure complementary pits', there is no satisfactory explanation why under similar physical circimstances matching halves of other membranes can be visualized. A prominent example of uncomplementarity is found in the erythrocyte manbrane. It is wall established that band 3 protein and possibly glycophorin represents these nonccmplanentary particles. On the other hand a number of membrane types show pits opposite the particles. Scme well known examples are the ";gap junction',"; tight junction, the luminal membrane of the bladder epithelial cells and the outer membrane of Escherichia coli.

Rho GTPase overactivation by E. coli CNF-1 disrupts epithelial tight junction structure and barrier function

2001 ◽  
Vol 120 (5) ◽  
pp. A110-A110
Author(s):  
A HOPKINS ◽  
S WALS ◽  
P VERKADE ◽  
P BOQUET ◽  
A NUSRAT
Keyword(s):  
Tight Junction ◽  
Barrier Function ◽  
Rho Gtpase ◽  
E Coli ◽  
Epithelial Tight Junction ◽  
Junction Structure

Tight junction proteins in HCC and metastatic liver tumours

2005 ◽  
Vol 43 (05) ◽  
Author(s):  
Cs Páska ◽  
E Orbán ◽  
A Kiss ◽  
Zs Schaff ◽  
A Szijjártó ◽  
...  
Keyword(s):  
Tight Junction ◽  
Tight Junction Proteins ◽  
Liver Tumours ◽  
Metastatic Liver ◽  
Junction Proteins
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