S Tsukita

..Specific signals activate ERM proteins to bind actin filaments and the plasma membrane; these include phosphoinositides and/or phosphorylation mechanisms, which might be located downstream from the Rho-dependent pathway...

..In good agreement, PDZ1 and PDZ2 domains of ZO-1/ZO-2/ZO-3 were also recruited to claudin-based TJs, when introduced into cultured epithelial cells. The possible molecular architecture of TJ plaque structures is discussed...

..From these findings, we conclude that ERM proteins bind to integral membrane proteins bearing a positively charged amino acid cluster in their juxta-membrane cytoplasmic domain...

..Furthermore, immunodetection with a phosphorylated ERM-specific antibody and site-directed mutagenesis suggested that ERM proteins phosphorylated at their COOH-terminal threonine residue represent activated ERM proteins...

..We also discuss the importance of this model from the perspective of the general molecular mechanisms behind the recruitment of PAR proteins to plasma membranes...

..These findings indicated that multiple claudin family members are involved in the formation of TJ strands in various tissues...

..Furthermore, we showed that outside the NB6-4T lineage most glial cells appeared independently of Pros...

....

..In addition, ZO-1 but not occludin were localized weakly at the outer root sheath and intensely at the hair cortex/matrix...

..e., the extracellular face-associated TJs. These findings indicated that claudin-5/TMVCF is an endothelial cell-specific component of TJ strands...

....

..These findings indicated that ZO-2 forms a complex with ZO-1/occludin or ZO-1/alpha catenin to establish TJ or AJ domains, respectively...

..We concluded that distinct species of claudins can interact within and between TJ strands, except in some combinations. This mode of assembly of claudins could increase the diversity of the structure and functions of TJ strands...

..These findings favor the notion that ERM proteins are functionally redundant at the cellular as well as the whole body level...

..These findings suggested that claudin-1 and -2 are mainly responsible for TJ strand formation, and that occludin is an accessory protein in some function of TJ strands...

....

..The physiological relevance of this ERM protein-based microvillar breakdown in apoptosis will be discussed...

..These findings indicate that Odf2 is a widespread KI-insoluble scaffold component of the centrosome matrix, which may be involved in the maturation event of daughter centrioles...

....

..Our studies showed that the interaction of alpha-catenin with the actin-based cytoskeleton through the ZO-1-binding domain is required for the strong state of E-cadherin-based cell adhesion activity...

..These findings indicate that there are as yet unidentified TJ integral membrane protein(s) which can form strand structures, recruit ZO-1, and function as a barrier without occludin...

....

..These findings suggest that the phosphorylation of occludin is a key step in tight junction assembly...

..Furthermore, the exclusive concentration of occludin at tight junctions in epithelial cells was confirmed by immunoreplica electron microscopy...

....

..These findings indicate that Rho regulates the CD44/ERM complex formation in vivo and that the phosphatidylinositol turnover may be involved in this regulation mechanism...

..In addition, connexin-immunoreactivity was also observed along tight junctional strands, suggesting that the gap junction may also form along the tight junctions...

....

..Furthermore, identification of the neurofibromatosis type 2 tumour suppressor, which shows striking sequence similarity to ERM proteins, has increased interest in this family...

..Now that claudins have been identified, the structure and functions of TJs should be determined in detail in molecular terms...

..Taken together with the biochemical and the crystal structural results obtained to date, the closed and open forms represent the inactive and active forms of radixin as cross-linkers between actin filaments and plasma membranes...

..This review discusses current understanding of the molecular architecture of tight-junction strands, focusing on the recent discovery of two distinct types of tight-junction-specific integral membrane proteins, occludin and claudins...

..The epidermis, which is a typical stratified epithelium, has tight junctions (TJs) in the granular layer, as do simple epithelia. So far, abnormalities of TJs and involvement of claudin-1 have been reported in tumours of simple epithelia...

..Implications of these data and novel experimental options in cell biological research are discussed...

..Here, we present an overview of current progress in the identification of TJ-specific integral membrane proteins...

..New insights into the molecular architecture of tight junctions allow us to now discuss the structure and functions of this unique cell-cell adhesion apparatus in molecular terms...

..These results showed that NB6-4T, but not NB6-4A, requires cell cycle progression for acquisition of glial fate, suggesting that distinct mechanisms trigger glial differentiation in the different lineages...

..These results strongly suggest that Drosophila has a cell adhesion machinery homologous to the vertebrate cadherin-catenin system...

..9 (2), b = 151.2 (2), c = 71.2 (1) A, and contain two protein complexes in the crystallographic asymmetric unit. A 2.9 A resolution data set was collected using synchrotron radiation at SPring-8...

..These findings showed that the APC-EB1 interaction is regulated within cells and is allowed near the ends of microtubules only under restricted conditions...

..Our results imply that claudin-1 is involved in the beta-catenin-Tcf/LEF signaling pathway, and that increased expression of claudin-1 may have some role in colorectal tumorigenesis...

....

..44 (9), c = 99.49 (6) A, and contain one complex in the crystallographic asymmetric unit. An intensity data set was collected to a resolution of 2.60 A...

..We propose that there is a fundamental difference in the mode of classic cadherin-mediated cell-cell adhesion between chordate and nonchordate metazoans...

..Thus, claudins are responsible for TJ-specific obliteration of the intercellular space...

..Possible functions of the 220-kD protein (ZO-1) are discussed with special reference to the molecular mechanism for adherens and tight junction formation...

..These findings indicate that genetic abnormality of beta-catenin is one of the mechanisms responsible for loosening of cell-cell contact, and may be involved in enhancement of tumor invasion in human cancers...

..These findings suggest that the desmoyokin/AHNAK protein is a ubiquitous molecule with a unique structure and appears to have different distributions (and probably different functions) among different cells...

..The possible functions of beta catenin are discussed with a special reference to its role as a negative regulator for the cadherin-mediated cell adhesion system...

..The coincidence of the sequence necessary for the ZO-1 association with that for the TJ localization suggests that the association with underlying cytoskeletons through ZO-1 is required for occludin to be localized at TJ...

..1 protein described in this study favors the idea that radixin plays a crucial role in the association of the barbed ends of actin filaments with the plasma membrane in the cell-to-cell adherens junction and the cleavage furrow...

..The same effect was observed by introducing N- or P-cadherin into L cells...

..In addition, occludin expression can serve as a histopathological indicator for differentiation in gastrointestinal adenocarcinomas...

..Our data indicate that regulation of occludin expression may be a crucial determinant of the tight junction permeability properties of endothelial cells in different tissues...

..These results suggest that ERM as well as Rho GDI and the Rho GDP/GTP exchange factor are involved in the activation of the Rho subfamily members, which then regulate reorganization of actin filaments through the ERM system...

..These results suggest that l-afadin serves as a linker of the actin cytoskeleton to the plasma membrane at cell-to-cell AJ...

..Moreover, the processes responsible for loss of epithelial cell polarity and elimination of preexisting DE-cadherin-based epithelial junctions during early mesodermal morphogenesis are discussed...

..We conclude that at least one of the members of the ezrin-radixin-moesin family is concentrated at specific regions where actin filaments are densely associated with plasma membranes...

..Thus, the Dalpha-catenin-GFP fusion protein is a helpful tool to simultaneously observe morphogenetic movements and AJ dynamics at high spatio-temporal resolution...

..In this study, we describe the initial characterization of these new members and discuss the evolution of the band 4.1 superfamily...

....

..This study provides a new animal model of autoimmune myocarditis which may shed light on the pathogenesis of dilated cardiomyopathy...

..These findings revealed that an integral membrane protein localizing at tight junctions is now identified, which we designated as "occludin."..

..2% homologous. Analysis by reverse transcription-PCR revealed that this gene is expressed ubiquitously in normal tissues. It was mapped to chromosome band 5q31 by fluorescent in situ hybridization...

..Our results favored a treadmilling model for actin behavior in border cell lamellipodia...

..Movies available on-line: http://www.biologists.com/JCS/movies/jcs2073.html..

..These phenotypes suggested that the functions of TJs as well as occludin are more complex than previously supposed...

..These deletions were probably produced by an error of RNA splicing, presenting one possible mechanism for the loss of intact alpha-catenin expression...

..We conclude that E14 is a novel undercoat-constitutive protein found in certain types of cell-to-cell adherens junctions...

..This study aimed at functional characterization of the tight junction protein occludin using the occludin-deficient mouse model...