| First Author | Kubota K | Year | 1999 |
| Journal | Curr Biol | Volume | 9 |
| Issue | 18 | Pages | 1035-8 |
| PubMed ID | 10508613 | Mgi Jnum | J:113790 |
| Mgi Id | MGI:3687671 | Doi | 10.1016/s0960-9822(99)80452-7 |
| Citation | Kubota K, et al. (1999) Ca(2+)-independent cell-adhesion activity of claudins, a family of integral membrane proteins localized at tight junctions. Curr Biol 9(18):1035-8 |
| abstractText | In multicellular organisms, various compositionally distinct fluid compartments are established by epithelial and endothelial cellular sheets. For these cells to function as barriers, tight junctions (TJs) are considered to create a primary barrier for the diffusion of solutes through the paracellular pathway [1] [2] [3]. In ultrathin sections viewed under electron microscopy, TJs appear as a series of apparent fusions, involving the outer leaflets of plasma membranes of adjacent cells, to form the so-called kissing points of TJs, where the intercellular space is completely obliterated [4]. Claudins are a family of 16 proteins whose members have been identified as major integral membrane proteins localized exclusively at TJs [5] [6] [7] [8]. It remains unclear, however, whether claudins have the cell-adhesion activity that would explain the unusual intercellular adhesion at TJs. Using mouse L-fibroblast transfectants expressing various amounts of claudin-1, -2 or -3, we found that these claudins possess Ca(2+)-independent cell-adhesion activity. Using ultrathin-section electron microscopy, we observed many kissing points of TJs between adjacent transfectants. Furthermore, the cell-adhesion activity of occludin, another integral membrane protein localized at TJs [9] [10] [11], was negligible when compared with that of claudins. Thus, claudins are responsible for TJ-specific obliteration of the intercellular space. |
