| First Author | Adachi M | Year | 2006 |
| Journal | Mol Cell Biol | Volume | 26 |
| Issue | 23 | Pages | 9003-15 |
| PubMed ID | 17000770 | Mgi Jnum | J:117589 |
| Mgi Id | MGI:3696930 | Doi | 10.1128/MCB.01811-05 |
| Citation | Adachi M, et al. (2006) Normal establishment of epithelial tight junctions in mice and cultured cells lacking expression of ZO-3, a tight-junction MAGUK protein. Mol Cell Biol 26(23):9003-15 |
| abstractText | ZO-1, ZO-2, and ZO-3 are closely related MAGUK family proteins that localize at the cytoplasmic surface of tight junctions (TJs). ZO-1 and ZO-2 are expressed in both epithelia and endothelia, whereas ZO-3 is exclusively expressed in epithelia. In spite of intensive studies of these TJ MAGUKs, our knowledge of their functions in vivo, especially those of ZO-3, is still fragmentary. Here, we have generated mice, as well as F9 teratocarcinoma cell lines, that do not express ZO-3 by homologous recombination. Unexpectedly, ZO-3(-/-) mice were viable and fertile, and rigorous phenotypic analyses identified no significant abnormalities. Moreover, ZO-3-deficient F9 teratocarcinoma cells differentiated normally into visceral endoderm epithelium-like cells in the presence of retinoic acid. These cells had a normal epithelial appearance, and the molecular architecture of their TJs did not appear to be affected, except that TJ localization of ZO-2 was upregulated. Suppression of ZO-2 expression by RNA interference in ZO-3(-/-) cells, however, did not affect the architecture of TJs. Furthermore, the speed with which TJs formed after a Ca(2+) switch was indistinguishable between wild-type and ZO-3(-/-) cells. These findings indicate that ZO-3 is dispensable in vivo in terms of individual viability, epithelial differentiation, and the establishment of TJs, at least in the laboratory environment. |
